Performance of genotypic algorithms for predicting tropism of HIV-1CRF02_AG subtype.

BACKGROUND: Several genotypic rules for predicting HIV-1 non-B subtypes tropism are commonly used, but there is no consensus about their performances. OBJECTIVES: Three genotypic methods were compared for CRF02_AG HIV-1 tropism determination. STUDY DESIGN: V3 env region of 178HIV-1 CRF02_AG from Pitié-Salpêtrière and Saint-Antoine Hospitals was sequenced from plasma HIV-1 RNA. HIV-1 tropism was determined by Geno2Pheno algorithm, false positive rate (FPR) 5% or 10%, the 11/25 rule or the combined criteria of the 11/25 and net charge rule. RESULTS: A concordance of 91.6% was observed between Geno2pheno 5% and the combined criteria. The results were nearly similar for the comparison between Geno2pheno 5% and the 11/25 rule. More mismatches were observed when Geno2pheno was used with the FPR 10%. A lower nadir CD4 cell count was associated with a discordance of tropism prediction between Geno2pheno 5% and the combined criteria or the 11/25 rule (p=0.02 and p=0.03, respectively). A lower HIV-1 viral load was associated with some discordance for the comparison of Geno2pheno 10% and the combined rule (p=0.02). CONCLUSION: Geno2pheno FPR 5% or 10% predicted more X4-tropic viruses for this set of CRF02_AG sequences than the combined criteria or the 11/25 rule alone. Furthermore, Geno2pheno FPR 5% was more concordant with the 11/25 rule and the combined rule than Geno2pheno 10% to predict HIV-1 tropism. Overall, Geno2pheno 5% could be used to predict CRF02_AG tropism as well as other genotypic rules.

Early legume responses to inoculation with Rhizobium sp. NGR234.

Interactions between legumes and rhizobia are controlled by the sequential exchange of symbiotic signals. Two different techniques, 2D-PAGE electrophoresis and differential display were used to study the effects of rhizobial signals on legume development. Application of variously substituted lipo-oligo-saccharidic Nod-factors to roots of Vigna unguiculata resulted in changes in the phosphorylation patterns of microsomal proteins. Reliable amino-acid sequences were obtained for one Nod-factor enhanced protein which was highly homologous to the 57-kDa subunit from Arabidopsis thaliana vacuolar membrane H(+)-ATPase. Immuno-blotting techniques demonstrated that Nod-factors cause rapid and massive increases of this enzyme in treated roots, suggesting that H(+)-ATPases play symbiotic roles. Concomitantly, we used differential display (DD) techniques on mRNA isolated from root-hairs to analyse early root responses to NGR234. Significant matches of several DD clones to known sequences were found. Clone D2.62 was homologous to a multitude of receptor kinases including S receptor-like kinases of A. thaliana and clone D4.1 showed similarities to Lotus japonicus phosphatidylinositol transfer-like protein III and late nodulin 16. Independent confirmatory analyses of these differentially expressed clones indicated expression at very low levels.

Assessment of cetirizine, an antihistamine, to prevent cutaneous reactions to nevirapine therapy: results of the viramune-zyrtec double-blind, placebo-controlled trial.

We conducted a 12-week, multicenter, randomized, double-blind, placebo-controlled trial of cetirizine to assess the ability of antihistamines to prevent nevirapine-associated rash in patients infected with human immunodeficiency virus type 1. Patients initiating treatment with nevirapine were randomized to receive either cetirizine, 10 mg q.d. (104 patients), or placebo (96 patients) during the first 6 weeks of therapy. Rash occurred in 22 (11%) of 200 patients; 10 (9.6%) were in the cetirizine group and 12 (12.5%) were in the placebo group (odds ratio [OR], 0.75; 95% confidence interval [CI], 0.31-1.81; P=.5). Five of 22 rashes were cases of hypersensitivity syndrome. The rate of nevirapine discontinuation due to rash was similar in the 2 groups (7.7% and 6.25% in the cetirizine and placebo groups, respectively; P=.4). Multivariate analysis showed no treatment-group effect but indicated that age >40 years (OR, 3.83; 95% CI, 1.4-10.46; P=.008) was associated with an increased risk of rash. Cetirizine has no preventive effect on nevirapine-associated rash.

[Predictive factors of virologic response to antiretroviral treatment with a protease inhibitor in HIV infection]. / Facteurs prédictifs de réponse virologique à un traitement antirétroviral avec inhibiteur de protéase au cours de l'infection à VIH.

OBJECTIVE: To investigate factors related to early virological response among a cohort of 224 patients who started a protease inhibitor (PI) for the first time. To determine which factors are associated with persistent response among patients with early response. PATIENTS AND METHODS: Early complete response was defined as an undetectable plasma viral load 2 to 3 months after treatment onset (< 400 copies/ml, Quantiplex HIV 2.0 Chiron diagnostics), incomplete response as at least 1 log reduction of viral load. In patients with an undetectable plasma viral load at 2 or 3 months, we also assessed the persistence of the response on the same regimen. Virology failure was defined by two consecutive viral load levels above the detection limit. RESULTS: In the total cohort, 66% of the patients had an early complete response, 11% a partial response and 23% no response. Complete virological response was significantly more frequent in naive (89%) than in pretreated (59%) patients (p < 0.001). Multivariate analysis of factors predictive of early response in pretreated patients (n = 169) showed that viral load (p = 0.001), the number of nucleoside analogs previously received (p = 0.06) and a full or partial treatment switch (p = 0.10) were associated with complete response. Analysis of later response in the 45 naive patients with prolonged follow-up showed that 22% had treatment failure after 3 to 16 months. None of the baseline variables (viral load, CD4+ cell count or nature of the PI) were associated with duration of response. The only factor associated with persistent response in pretreated patients was a low number of antiretroviral drugs previously received (log-rank test, p = 0.04). CONCLUSIONS: The absence of previous antiretroviral treatment as the main factor associated with an early complete virological response. In patients pretreated with nucleoside analogs who presented early virological success, the number of drugs previously received, often associated with full or partial switch of nucleoside analog, significantly influence the persistence of response to a given triple-drug regimen.

Plasma cytomegalovirus DNA, pp65 antigenaemia and a low CD4 cell count remain risk factors for cytomegalovirus disease in patients receiving highly active antiretroviral therapy.

OBJECTIVE: To study the natural history and the current risk factors for cytomegalovirus (CMV) disease in the context of highly active antiretroviral therapy (HAART). SETTING: Prospective multicentre cohort in 15 university hospitals in France. METHODS: A group of 198 patients with CD4 cell count < 100 x 10(6) cells/l (or < 200 x 10(6) cells/l under HAART for at least 2 months), no previous CMV disease and CMV-positive serology were followed every 4 months clinically and for virological testing including HIV RNA and CMV blood markers (culture, pp65 antigenaemia, plasma CMV DNA and CMV late mRNA by the polymerase chain reaction). RESULTS: At inclusion, median CD4 was 77 x 10(6) cells/l (0-308) and 85% of the patients received protease inhibitors. The percentage of patients receiving HAART reached 99% at 12 months. After a follow-up of 23.6 months, the incidence of CMV disease was 3.2/100 patient-years [95% confidence interval (CI) 1.3-5.0]. In univariate Cox models, all the CMV markers, a CD4 cell count remaining < 75 x 10(6) cells/l and an HIV viral load > 100,000 copies/ml were predictive for CMV disease. The hazard ratios for CMV disease were 11 for blood culture; 14 and 70 for pp65 antigenaemia of > or = 1 and > or = 100 nuclei/200,000 cells, respectively; 35 for plasma CMV DNA; 6 for CMV mRNA; 29 for CD4 < 75 x 10(6) cells/l; and 12 for HIV RNA > 100,000 copies/ml. In a stepwise multivariate analysis, only three covariates were independently associated with the occurrence of a disease: plasma CMV DNA, pp65 antigenaemia > or = 100 nuclei/200,000 cells and a CD4 count < 75 x 10(6) cells/l. CONCLUSION: CMV blood markers and CD4 count < 75 x 10(6) cells/l remain risk factors for CMV disease in patients receiving HAART. Analysis of plasma CMV DNA by the polymerase chain reaction is a reproducible and standardized tool that could be used as a decision marker for initiating CMV pre-emptive therapy.

Induction and maintenance therapy of cytomegalovirus central nervous system infection in HIV-infected patients.

OBJECTIVE: To evaluate the efficacy and safety of the foscarnet-ganciclovir combination in induction therapy (IT) and maintenance therapy (MT) for cytomegalovirus (CMV) central neurological disorders in HIV-infected patients. DESIGN: An open pilot non-comparative multicentre study. METHODS: Thirty-one patients with acute CMV encephalitis (CMVe) (n = 17) or CMV myelitis (CMVm) (n = 14) during the era before highly active antiretroviral therapy (HAART) received intravenous IT with foscarnet 90 mg/kg plus ganciclovir 5 mg/kg twice a day followed by MT. The primary endpoint was clinical efficacy, assessed at the end of the induction phase. RESULTS: The foscarnet-ganciclovir combination in IT resulted in a 74% (23 out of 31 patients) clinical improvement or stabilization. Eight patients did not respond clinically. Side-effects leading to drug discontinuation occurred in 10 patients during IT. Among the 23 patients who qualified for the maintenance phase, CMV disease progressed in 10, with a median time to the first relapse of 126 days (range 64-264 days). Overall, the median survival time was 3 months [95% confidence interval (CI), 2-4 months]. CONCLUSION: The combination of foscarnet and ganciclovir can safely be used for CMV central nervous system (CNS) infection, with an improvement or stabilization in 74% of patients. Life-long MT with this combination is recommended as long as the immune system is profoundly impaired.

Parvovirus B19 infection, hepatitis C virus infection, and mixed cryoglobulinaemia.

BACKGROUND: Infection with human parvovirus B19 (B19) has been reported in a few patients with various vasculitis syndromes. Mixed cryoglobulinaemia (MC), a model of small vessel size vasculitis, may result from numerous infectious diseases, particularly hepatitis C virus (HCV) infection. AIM: To assess the prevalence of seric B19 infection markers in a large series of patients with MC, with or without HCV infection. PATIENTS AND METHODS: Sixty-four patients were studied: essential MC (EMC, n = 19), MC associated with non-infectious diseases (non-essential MC, n = 9), and patients with HCV infection with (HCV-MC, n = 18) or without MC (HCV-no-MC, n = 18). Patients were considered to have MC if two successive determinations of their serum cryoglobulin concentration were above 0.05 g/l. Serum samples were analysed for specific IgG and IgM antibodies to B19 by enzyme immunoassay. B19 DNA detection was performed by polymerase chain reaction using a set of primers located in the VP1 gene, separately in serum and in cryoprecipitates to investigate a possible capture of B19 DNA in cryoprecipitate. The study also looked for a possible enrichment for of IgG antibodies to B19 in MC. RESULTS: The presence of specific IgG antibodies to B19 was found in 68% EMC, 56% non-essential MC, 78% HCV-MC, and 78% HCV-no-MC. No patient of either group had specific IgM antibodies to B19, or B19 DNA in serum or in cryoprecipitate. Overall, IgG antibodies to B19 were found in 46 of 64 (72%) serum samples, a prevalence quite similar to the prevalence in general adult population (> 60%). A specific enrichment of IgG antibodies to B19 in the MC was not found. CONCLUSION: These results suggest that B19 infection is neither an aetiological factor of EMC, nor a cofactor that may lead to MC production in patients with chronic HCV infection.