The interaction of leech-derived tryptase inhibitor (LDTI) with bovine liver capsule tryptase (BL... more The interaction of leech-derived tryptase inhibitor (LDTI) with bovine liver capsule tryptase (BLCT) and bovine trypsin has been studied using both thermo-dynamic and kinetic approaches. Several differences were detected: (i) the equilibrium affinity of LDTI for BLCT (Ka = 8.9 105 M–1) is about 600-fold lower than that for bovine trypsin (Ka = 5.1 108 M–1); (ii) LDTI be-haves as a purely non-competitive inhibitor of BLCT, while it is a purely competitive inhibitor of bovine tryp-sin. These functional data are compared with those previously reported for the LDTI binding to human tryptase, where tight inhibition occurs at two of the four active sites of the tetramer (Ka = 7.1 108 M–1). Amino acid sequence alignment of BLCT, human II-tryptase and bovine trypsin allows us to infer some possible structural basis for the observed functional differences.
The service that Global Health Telemedicine offers aims to increase the diagnostic and therapeuti... more The service that Global Health Telemedicine offers aims to increase the diagnostic and therapeutic indications of the clinical cases in the most remote areas of Africa and not only Africa.
Background. Since February 2002 the DREAM programme, run in Mozambique by the Community of Sant’E... more Background. Since February 2002 the DREAM programme, run in Mozambique by the Community of Sant’Egidio, provided free-of-charge to the patients both HAART and immunological and virological monitoring. Methods: DREAM is working in the Mozambican public health sector. HAART is offered to eligible HIV positive patients in both day hospital and home care service. Health education as well as nutritional assessment and supplementation are included in the protocol. As on 15th August 2003, 802 HIV+ individuals (510 female) are included in the community and home care programme run in the Machava center (Maputo province): close to 50% had a CD4 count below 200/mm3 and more than one third was 3-4 WHO clinical stage. Generic ARV are provided to the patients. Results: More than 50% of patients met the criteria to start ARV treatment. The overall rate of lost to follow up was 9.3%, higher in the not treated group (12.7% vs 7.2%). Patient receiving HAART had more likely a lower CD4 count (median v...
The use of dried blood spots (DBS) for HIV-1 viral load quantification can greatly improve access... more The use of dried blood spots (DBS) for HIV-1 viral load quantification can greatly improve access to viral monitoring for HIV-infected patients receiving treatment in resource-limited settings. To evaluate and validate HIV viral load measurement from DBS in sub-Saharan Africa, with a reliable, all-automated, standard commercial assay such as the Abbott m2000. A total of 277 DBS were collected in different health centres in Malawi and Mozambique and analysed for viral load determination using the Abbott m2000 assay with the corresponding plasma samples as gold standard. Samples were extracted using the m2000SP automatic extractor and then processed as the plasma samples using the specific 1.0 mL HIV-RNA DBS protocol. Among samples with detectable HIV-RNA the correlation between viral load obtained from the paired 131 plasma and DBS samples was high (r=0.946). Overall, viral load values between DBS and plasma differed by less than 0.5 log unit in 90.1% of cases and by less than 1 log unit in 100% of cases. Using a threshold of 1 000 copies/mL (defining virological failure in resource-limited settings), sensitivity was 94.2% and specificity 98.6%, and both positive and negative predictive values were high (98.5% and 94.5%, respectively). DBS extracted and processed using the Abbott automated system can be reliably used in resource-limited setting to diagnose virological failure.
Assessing treatment efficacy and early infant diagnosis (EID) are critical issues in HIV disease ... more Assessing treatment efficacy and early infant diagnosis (EID) are critical issues in HIV disease management. Point-of-care assays may greatly increase the possibility to access laboratory monitoring also in rural areas. Recently two new laboratory tests have been developed by Cepheid (Sunnyvale, California) the Xpert HIV-1 Viral Load for viral load determination and the Xpert HIV-1 Qualitative for early infant diagnosis. We conducted a study in Blantyre, Malawi, comparing the 2 methods versus the Abbott real time quantitative and qualitative assays, for viral load and EID respectively. We tested 300 plasma samples for viral load determination and 200 samples for infant diagnosis. HIV-1 RNA values of the 274 samples quantified by both assays were highly correlated (Pearson r=0.95, R(2)=0.90). In 90.9% of the cases the two methods were concordant in defining the HIV-1 RNA levels as detectable or undetectable. For EID, the Xpert HIV-1 Qualitative assay yielded the same identical results as the Abbott assay. Both the quantitative and the qualitative Xpert assays are promising tools to monitor treatment efficacy in HIV patients receiving treatment and for early diagnosis in HIV-exposed infants.
Journal of the International Association of Providers of AIDS Care, Jan 28, 2015
Combination antiretroviral therapy has been shown to reduce HIV transmission and incident infecti... more Combination antiretroviral therapy has been shown to reduce HIV transmission and incident infections. In recent years, Malawi has significantly increased the number of individuals on combination antiretroviral drugs through more inclusive treatment policies. Using a retrospective observational cohort design, records with HIV test results were reviewed for pregnant women attending a referral hospital in Malawi over a 5-year period, with viral load measurements recorded. HIV prevalence over time was determined, and results correlated with population viral load. A total of 11 052 women were included in this analysis, with 440 (4.1%) HIV infections identified. HIV prevalence rates in pregnant women in Malawi halved from 6.4% to 3.0% over 5 years. Mean viral loads of adult patients decreased from 120 000 copies/mL to less than 20 000 copies/mL. Results suggest that community viral load has an effect on HIV incidence rates in the population, which in turn correlates with reduced HIV preva...
A complementary DNA encoding a new bovine tryptase isoform (here named BLT) was cloned and sequen... more A complementary DNA encoding a new bovine tryptase isoform (here named BLT) was cloned and sequenced from lung tissue. Analysis of sequence indicates the presence of a 26-amino acid prepro-sequence and a 245 amino acid catalytic domain. It contains six different residues when compared with the previously characterized tryptase from bovine liver capsule (BLCT), with the most significant difference residing at the primary specificity S1 pocket. In BLT, the canonical residues Asp-Ser are present at positions 188–189, while in BLCT these positions are occupied by residues Asn-Phe. This finding was confirmed by mass fingerprinting of the peptide mixture obtained upon in-gel tryptic digestion of BLT. Analysis by gel filtration of the purified protein shows that BLT is probably tetrameric, similar to the previously identified tryptases from other species, with monomer migrating as 35–40 kDa multiple bands in SDS/PAGE. As expected, the catalytic abilities of the two bovine tryptases are dif...
Annali di igiene : medicina preventiva e di comunità
Kaposi Sarcoma shows several different clinical and epidemiological patterns. In Sub-Saharan Afri... more Kaposi Sarcoma shows several different clinical and epidemiological patterns. In Sub-Saharan Africa, where the HIV achieves an high prevalence of infection, the KS can be found both in HIV positive than in HIV negative patients, and the diffusion of the HHV8 virus is endemic. The aim of the work is to evaluate the HHV8 seroprevalence in Mozambique. Moreover the relationship of some main indicators, as CD4 and CD8 cells count, HIV viral load, Body Mass Index and haemoglobin values have been calculated in a part of the DREAM Cohort, (HIV positive patients enrolled in the Community of Sant'Egidio program to fight AIDS in the Sub-Saharan Africa). In the HIV positive cohort HHV8 negative and HHV8 positive groups show statistical significance (p < 0.05) in CD4 cells count, a strong significance (p = 0.01) in CD8 cells count and a significance also in Haemoglobin levels (p = 0.35). The difference in Haemoglobin levels (0.5 g/dl) is related more to a statistical than a clinical signi...
Bovine tryptase, a mast cell trypsin-like protease, was isolated from liver capsula and from mast... more Bovine tryptase, a mast cell trypsin-like protease, was isolated from liver capsula and from mast cells obtained from the same tissue. The purification procedure which leads to an increase in tryptase activity of 850 fold, involves high salt extraction, hydrophobic interaction chromatography on octyl-Sepharose and affinity chromatography on heparin-Sepharose. The enzyme is oligomeric, with an apparent M(r) of 360,000 +/- 40,000 (as obtained by gel filtration in high salt). The constituent subunits with M(r) 39,000 and 41,000 Da are both labeled with [3H] diisopropyl fluorophosphate and cross-react with anti-rat tryptase immunoglobulins. Only a single N-terminal sequence was found, identical to that of human, dog and rat tryptases. Tripeptide fluorogenic substrates with basic residues in P1 and P2 positions are preferentially hydrolyzed by this enzyme, suggesting a possible processing role as proposed for other tryptases. Bovine tryptase activity is inhibited by NaCl and is insensitive to high molecular weight inhibitors, such as alpha 1 antitrypsin and soybean trypsin inhibitor, as for human and dog tryptases. However it is inhibited by low molecular weight serine protease inhibitors and, similarly to rat tryptase, by the bovine pancreatic trypsin inhibitor (BPTI or aprotinin), in a pH dependent fashion.
Nevirapine (NVP) is a non-nucleoside reverse transcriptase inhibitor, widely prescribed for type ... more Nevirapine (NVP) is a non-nucleoside reverse transcriptase inhibitor, widely prescribed for type 1 human immunodeficiency virus infection. A small proportion of individuals treated with NVP experience severe cutaneous adverse events, including Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). Our aim was to verify whether genetic variability in NVP-metabolizing cytochromes or in transporter genes could be involved in susceptibility to SJS/TEN. Twenty-seven patients with NVP-induced SJS/TEN and 78 controls, all from Mozambique, were genotyped for the ABCB1 and ABCC10 transporter genes and for CYP2B6, CYP3A4 and CYP3A5 cytochrome gene variants. A case-control and a genotype-phenotype analysis were performed. CYP2B6 G516T and T983C single nucleotide polymorphisms (SNPs) were found to be associated with SJS/TEN susceptibility. The 983C allele in particular was found to be highly associated with a higher risk to develop SJS/TEN [odds ratio (OR) 4.2, P = 0.0047]. The GT haplotype (wildtype for both SNPs) showed a protective effect, with an OR = 0.33 (P = 0.0016). This is the first study showing that genetic variability in a metabolizing enzyme can also contribute to NVP-induced SJS/TEN susceptibility.
Nevirapine (NVP) is an anti-retroviral drug used for the treatment of HIV infection, that may cau... more Nevirapine (NVP) is an anti-retroviral drug used for the treatment of HIV infection, that may cause several severe adverse events, including Stevens Johnsons Syndrome/Toxic Epidermal Necrolysis (SJS/TEN). A recent whole genome association study highlighted a strong association with allopurinol-induced SJS/TEN within the HCP5 and PSORS1C1 genes in the Japanese population. Our aim was to verify the contribution of these two genes in the susceptibility to NVP-induced SJS/TEN in a population from Mozambique. Genotyping of PSORS1C1 rs2233945 and HCP5 rs3099844 SNPs was performed in a sample of 27 patients with SJS/TEN and 76 controls. A case-control and a haplotype analysis were performed. The HCP5 rs3099844 variant allele was significantly associated with the SJS/TEN susceptibility (OR = 2.03 and P = 0.039). The TA haplotype, carrying both the variant alleles of the two genes, showed a higher risk for developing SJS/TEN (OR = 3.44and P = 0.003). The regression analysis confirmed the contribution of HCP5 rs3099844 SNP (OR = 2.05, P = 0.047). By a log-linear model, we also investigated for interaction between HCP5 rs309844 and PSORS1C1 rs2233945 SNPs with respect to SJS/TEN risk, and we observed a strong interaction between the two SNPs (P = 0.005). We confirmed the association of HCP5 with the SJS/TEN susceptibility in a population from Mozambique treated with NVP.
Limited information is available on antiretroviral concentrations in women/infant pairs receiving... more Limited information is available on antiretroviral concentrations in women/infant pairs receiving prophylaxis for breastfeeding transmission of HIV and on the relationship between drug levels and the virological and haematochemistry parameters. Patient population included HIV-positive pregnant women receiving antiretroviral prophylaxis from gestational week 25 until 6 months after delivery and their breastfed infants. Blood and breast milk samples were collected at delivery, and at months 1, 3 and 6 postpartum. Drug concentrations were measured by liquid chromatography-mass spectrometry. Overall, 66 women were studied: 29 received zidovudine (ZDV), lamivudine (3TC) and nevirapine (NVP), 28 stavudine (d4T), 3TC and NVP, and 9 ZDV, 3TC and lopinavir/ritonavir (LPV/r). Women who received &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;9 weeks of pre-partum prophylaxis were significantly more likely to have an undetectable viral load both in plasma and in breast milk at delivery. No emergence of resistance mutations was observed in breast milk. Breast milk/plasma concentration ratios were 0.6 for ZDV, 3TC and NVP, 1.0 for d4T and 0.4 for LPV/r. Only NVP reached significant levels in the infants. No correlation with any adverse events, including infant anaemia, was observed with drug concentrations. Two infants who acquired HIV infection had non-nucleoside reverse transcriptase inhibitor mutations at month 6. Maternal administration of these three regimens up to 6 months postpartum was effective and safe for both mothers and infants. No significant correlation was found between drug concentrations and infant haematological parameters, supporting the hypothesis that other factors may contribute to the development of anaemia in these settings.
The pH and temperature dependence of both the kinetic and thermodynamic properties of the Thr72→I... more The pH and temperature dependence of both the kinetic and thermodynamic properties of the Thr72→Ile mutant of Scapharca inaequivalvis homodimeric hemoglobin were investigated between pH 2 and 10 and between 8 �C and 36 �C, in comparison with the wild-type recombinant protein. Results demonstrate pH-independent O2-binding properties, at least between pH 5 and 10, with the higher affinity of the mutant being related to
To avoid overdiagnosis, accuracy in the identification of true malaria cases is of critical impor... more To avoid overdiagnosis, accuracy in the identification of true malaria cases is of critical importance. Samples (either whole blood, dried blood spots or plasma/serum) collected at the time of clinically diagnosed malaria episodes in a cohort of Malawian HIV-infected mothers and their children were retrospectively tested with the enzyme-linked immunosorbent assay (ELISA) for HRP-2 (histidine-rich protein 2) detection. There were 55 and 56 clinically diagnosed cases of malaria in mothers and children, respectively, with samples available for testing. Rates of laboratory-confirmed episodes were 20% (11 of 55) in mothers and 16.1% (9 of 56) in children. Hemoglobin was lower in children with confirmed malaria compared to those with clinical malaria diagnosis. The results of our study support the widespread use of rapid diagnostic tests.
The interaction of leech-derived tryptase inhibitor (LDTI) with bovine liver capsule tryptase (BL... more The interaction of leech-derived tryptase inhibitor (LDTI) with bovine liver capsule tryptase (BLCT) and bovine trypsin has been studied using both thermo-dynamic and kinetic approaches. Several differences were detected: (i) the equilibrium affinity of LDTI for BLCT (Ka = 8.9 105 M–1) is about 600-fold lower than that for bovine trypsin (Ka = 5.1 108 M–1); (ii) LDTI be-haves as a purely non-competitive inhibitor of BLCT, while it is a purely competitive inhibitor of bovine tryp-sin. These functional data are compared with those previously reported for the LDTI binding to human tryptase, where tight inhibition occurs at two of the four active sites of the tetramer (Ka = 7.1 108 M–1). Amino acid sequence alignment of BLCT, human II-tryptase and bovine trypsin allows us to infer some possible structural basis for the observed functional differences.
The service that Global Health Telemedicine offers aims to increase the diagnostic and therapeuti... more The service that Global Health Telemedicine offers aims to increase the diagnostic and therapeutic indications of the clinical cases in the most remote areas of Africa and not only Africa.
Background. Since February 2002 the DREAM programme, run in Mozambique by the Community of Sant’E... more Background. Since February 2002 the DREAM programme, run in Mozambique by the Community of Sant’Egidio, provided free-of-charge to the patients both HAART and immunological and virological monitoring. Methods: DREAM is working in the Mozambican public health sector. HAART is offered to eligible HIV positive patients in both day hospital and home care service. Health education as well as nutritional assessment and supplementation are included in the protocol. As on 15th August 2003, 802 HIV+ individuals (510 female) are included in the community and home care programme run in the Machava center (Maputo province): close to 50% had a CD4 count below 200/mm3 and more than one third was 3-4 WHO clinical stage. Generic ARV are provided to the patients. Results: More than 50% of patients met the criteria to start ARV treatment. The overall rate of lost to follow up was 9.3%, higher in the not treated group (12.7% vs 7.2%). Patient receiving HAART had more likely a lower CD4 count (median v...
The use of dried blood spots (DBS) for HIV-1 viral load quantification can greatly improve access... more The use of dried blood spots (DBS) for HIV-1 viral load quantification can greatly improve access to viral monitoring for HIV-infected patients receiving treatment in resource-limited settings. To evaluate and validate HIV viral load measurement from DBS in sub-Saharan Africa, with a reliable, all-automated, standard commercial assay such as the Abbott m2000. A total of 277 DBS were collected in different health centres in Malawi and Mozambique and analysed for viral load determination using the Abbott m2000 assay with the corresponding plasma samples as gold standard. Samples were extracted using the m2000SP automatic extractor and then processed as the plasma samples using the specific 1.0 mL HIV-RNA DBS protocol. Among samples with detectable HIV-RNA the correlation between viral load obtained from the paired 131 plasma and DBS samples was high (r=0.946). Overall, viral load values between DBS and plasma differed by less than 0.5 log unit in 90.1% of cases and by less than 1 log unit in 100% of cases. Using a threshold of 1 000 copies/mL (defining virological failure in resource-limited settings), sensitivity was 94.2% and specificity 98.6%, and both positive and negative predictive values were high (98.5% and 94.5%, respectively). DBS extracted and processed using the Abbott automated system can be reliably used in resource-limited setting to diagnose virological failure.
Assessing treatment efficacy and early infant diagnosis (EID) are critical issues in HIV disease ... more Assessing treatment efficacy and early infant diagnosis (EID) are critical issues in HIV disease management. Point-of-care assays may greatly increase the possibility to access laboratory monitoring also in rural areas. Recently two new laboratory tests have been developed by Cepheid (Sunnyvale, California) the Xpert HIV-1 Viral Load for viral load determination and the Xpert HIV-1 Qualitative for early infant diagnosis. We conducted a study in Blantyre, Malawi, comparing the 2 methods versus the Abbott real time quantitative and qualitative assays, for viral load and EID respectively. We tested 300 plasma samples for viral load determination and 200 samples for infant diagnosis. HIV-1 RNA values of the 274 samples quantified by both assays were highly correlated (Pearson r=0.95, R(2)=0.90). In 90.9% of the cases the two methods were concordant in defining the HIV-1 RNA levels as detectable or undetectable. For EID, the Xpert HIV-1 Qualitative assay yielded the same identical results as the Abbott assay. Both the quantitative and the qualitative Xpert assays are promising tools to monitor treatment efficacy in HIV patients receiving treatment and for early diagnosis in HIV-exposed infants.
Journal of the International Association of Providers of AIDS Care, Jan 28, 2015
Combination antiretroviral therapy has been shown to reduce HIV transmission and incident infecti... more Combination antiretroviral therapy has been shown to reduce HIV transmission and incident infections. In recent years, Malawi has significantly increased the number of individuals on combination antiretroviral drugs through more inclusive treatment policies. Using a retrospective observational cohort design, records with HIV test results were reviewed for pregnant women attending a referral hospital in Malawi over a 5-year period, with viral load measurements recorded. HIV prevalence over time was determined, and results correlated with population viral load. A total of 11 052 women were included in this analysis, with 440 (4.1%) HIV infections identified. HIV prevalence rates in pregnant women in Malawi halved from 6.4% to 3.0% over 5 years. Mean viral loads of adult patients decreased from 120 000 copies/mL to less than 20 000 copies/mL. Results suggest that community viral load has an effect on HIV incidence rates in the population, which in turn correlates with reduced HIV preva...
A complementary DNA encoding a new bovine tryptase isoform (here named BLT) was cloned and sequen... more A complementary DNA encoding a new bovine tryptase isoform (here named BLT) was cloned and sequenced from lung tissue. Analysis of sequence indicates the presence of a 26-amino acid prepro-sequence and a 245 amino acid catalytic domain. It contains six different residues when compared with the previously characterized tryptase from bovine liver capsule (BLCT), with the most significant difference residing at the primary specificity S1 pocket. In BLT, the canonical residues Asp-Ser are present at positions 188–189, while in BLCT these positions are occupied by residues Asn-Phe. This finding was confirmed by mass fingerprinting of the peptide mixture obtained upon in-gel tryptic digestion of BLT. Analysis by gel filtration of the purified protein shows that BLT is probably tetrameric, similar to the previously identified tryptases from other species, with monomer migrating as 35–40 kDa multiple bands in SDS/PAGE. As expected, the catalytic abilities of the two bovine tryptases are dif...
Annali di igiene : medicina preventiva e di comunità
Kaposi Sarcoma shows several different clinical and epidemiological patterns. In Sub-Saharan Afri... more Kaposi Sarcoma shows several different clinical and epidemiological patterns. In Sub-Saharan Africa, where the HIV achieves an high prevalence of infection, the KS can be found both in HIV positive than in HIV negative patients, and the diffusion of the HHV8 virus is endemic. The aim of the work is to evaluate the HHV8 seroprevalence in Mozambique. Moreover the relationship of some main indicators, as CD4 and CD8 cells count, HIV viral load, Body Mass Index and haemoglobin values have been calculated in a part of the DREAM Cohort, (HIV positive patients enrolled in the Community of Sant'Egidio program to fight AIDS in the Sub-Saharan Africa). In the HIV positive cohort HHV8 negative and HHV8 positive groups show statistical significance (p < 0.05) in CD4 cells count, a strong significance (p = 0.01) in CD8 cells count and a significance also in Haemoglobin levels (p = 0.35). The difference in Haemoglobin levels (0.5 g/dl) is related more to a statistical than a clinical signi...
Bovine tryptase, a mast cell trypsin-like protease, was isolated from liver capsula and from mast... more Bovine tryptase, a mast cell trypsin-like protease, was isolated from liver capsula and from mast cells obtained from the same tissue. The purification procedure which leads to an increase in tryptase activity of 850 fold, involves high salt extraction, hydrophobic interaction chromatography on octyl-Sepharose and affinity chromatography on heparin-Sepharose. The enzyme is oligomeric, with an apparent M(r) of 360,000 +/- 40,000 (as obtained by gel filtration in high salt). The constituent subunits with M(r) 39,000 and 41,000 Da are both labeled with [3H] diisopropyl fluorophosphate and cross-react with anti-rat tryptase immunoglobulins. Only a single N-terminal sequence was found, identical to that of human, dog and rat tryptases. Tripeptide fluorogenic substrates with basic residues in P1 and P2 positions are preferentially hydrolyzed by this enzyme, suggesting a possible processing role as proposed for other tryptases. Bovine tryptase activity is inhibited by NaCl and is insensitive to high molecular weight inhibitors, such as alpha 1 antitrypsin and soybean trypsin inhibitor, as for human and dog tryptases. However it is inhibited by low molecular weight serine protease inhibitors and, similarly to rat tryptase, by the bovine pancreatic trypsin inhibitor (BPTI or aprotinin), in a pH dependent fashion.
Nevirapine (NVP) is a non-nucleoside reverse transcriptase inhibitor, widely prescribed for type ... more Nevirapine (NVP) is a non-nucleoside reverse transcriptase inhibitor, widely prescribed for type 1 human immunodeficiency virus infection. A small proportion of individuals treated with NVP experience severe cutaneous adverse events, including Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). Our aim was to verify whether genetic variability in NVP-metabolizing cytochromes or in transporter genes could be involved in susceptibility to SJS/TEN. Twenty-seven patients with NVP-induced SJS/TEN and 78 controls, all from Mozambique, were genotyped for the ABCB1 and ABCC10 transporter genes and for CYP2B6, CYP3A4 and CYP3A5 cytochrome gene variants. A case-control and a genotype-phenotype analysis were performed. CYP2B6 G516T and T983C single nucleotide polymorphisms (SNPs) were found to be associated with SJS/TEN susceptibility. The 983C allele in particular was found to be highly associated with a higher risk to develop SJS/TEN [odds ratio (OR) 4.2, P = 0.0047]. The GT haplotype (wildtype for both SNPs) showed a protective effect, with an OR = 0.33 (P = 0.0016). This is the first study showing that genetic variability in a metabolizing enzyme can also contribute to NVP-induced SJS/TEN susceptibility.
Nevirapine (NVP) is an anti-retroviral drug used for the treatment of HIV infection, that may cau... more Nevirapine (NVP) is an anti-retroviral drug used for the treatment of HIV infection, that may cause several severe adverse events, including Stevens Johnsons Syndrome/Toxic Epidermal Necrolysis (SJS/TEN). A recent whole genome association study highlighted a strong association with allopurinol-induced SJS/TEN within the HCP5 and PSORS1C1 genes in the Japanese population. Our aim was to verify the contribution of these two genes in the susceptibility to NVP-induced SJS/TEN in a population from Mozambique. Genotyping of PSORS1C1 rs2233945 and HCP5 rs3099844 SNPs was performed in a sample of 27 patients with SJS/TEN and 76 controls. A case-control and a haplotype analysis were performed. The HCP5 rs3099844 variant allele was significantly associated with the SJS/TEN susceptibility (OR = 2.03 and P = 0.039). The TA haplotype, carrying both the variant alleles of the two genes, showed a higher risk for developing SJS/TEN (OR = 3.44and P = 0.003). The regression analysis confirmed the contribution of HCP5 rs3099844 SNP (OR = 2.05, P = 0.047). By a log-linear model, we also investigated for interaction between HCP5 rs309844 and PSORS1C1 rs2233945 SNPs with respect to SJS/TEN risk, and we observed a strong interaction between the two SNPs (P = 0.005). We confirmed the association of HCP5 with the SJS/TEN susceptibility in a population from Mozambique treated with NVP.
Limited information is available on antiretroviral concentrations in women/infant pairs receiving... more Limited information is available on antiretroviral concentrations in women/infant pairs receiving prophylaxis for breastfeeding transmission of HIV and on the relationship between drug levels and the virological and haematochemistry parameters. Patient population included HIV-positive pregnant women receiving antiretroviral prophylaxis from gestational week 25 until 6 months after delivery and their breastfed infants. Blood and breast milk samples were collected at delivery, and at months 1, 3 and 6 postpartum. Drug concentrations were measured by liquid chromatography-mass spectrometry. Overall, 66 women were studied: 29 received zidovudine (ZDV), lamivudine (3TC) and nevirapine (NVP), 28 stavudine (d4T), 3TC and NVP, and 9 ZDV, 3TC and lopinavir/ritonavir (LPV/r). Women who received &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;9 weeks of pre-partum prophylaxis were significantly more likely to have an undetectable viral load both in plasma and in breast milk at delivery. No emergence of resistance mutations was observed in breast milk. Breast milk/plasma concentration ratios were 0.6 for ZDV, 3TC and NVP, 1.0 for d4T and 0.4 for LPV/r. Only NVP reached significant levels in the infants. No correlation with any adverse events, including infant anaemia, was observed with drug concentrations. Two infants who acquired HIV infection had non-nucleoside reverse transcriptase inhibitor mutations at month 6. Maternal administration of these three regimens up to 6 months postpartum was effective and safe for both mothers and infants. No significant correlation was found between drug concentrations and infant haematological parameters, supporting the hypothesis that other factors may contribute to the development of anaemia in these settings.
The pH and temperature dependence of both the kinetic and thermodynamic properties of the Thr72→I... more The pH and temperature dependence of both the kinetic and thermodynamic properties of the Thr72→Ile mutant of Scapharca inaequivalvis homodimeric hemoglobin were investigated between pH 2 and 10 and between 8 �C and 36 �C, in comparison with the wild-type recombinant protein. Results demonstrate pH-independent O2-binding properties, at least between pH 5 and 10, with the higher affinity of the mutant being related to
To avoid overdiagnosis, accuracy in the identification of true malaria cases is of critical impor... more To avoid overdiagnosis, accuracy in the identification of true malaria cases is of critical importance. Samples (either whole blood, dried blood spots or plasma/serum) collected at the time of clinically diagnosed malaria episodes in a cohort of Malawian HIV-infected mothers and their children were retrospectively tested with the enzyme-linked immunosorbent assay (ELISA) for HRP-2 (histidine-rich protein 2) detection. There were 55 and 56 clinically diagnosed cases of malaria in mothers and children, respectively, with samples available for testing. Rates of laboratory-confirmed episodes were 20% (11 of 55) in mothers and 16.1% (9 of 56) in children. Hemoglobin was lower in children with confirmed malaria compared to those with clinical malaria diagnosis. The results of our study support the widespread use of rapid diagnostic tests.
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Papers by Fulvio Erba