Natural killer cells in HIV controller patients express an activated effector phenotype and do not up-regulate NKp44 on IL-2 stimulation.

Control of HIV replication in elite controller (EC) and long-term nonprogressor (LTNP) patients has been associated with efficient CD8(+)cytotoxic T-lymphocyte function. However, innate immunity may play a role in HIV control. We studied the expression of natural cytotoxicity receptors (NKp46, NKp30, and NKp44) and their induction over a short time frame (2-4 d) on activation of natural killer (NK) cells in 31 HIV controller patients (15 ECs, 16 LTNPs). In EC/LTNP, induction of NKp46 expression was normal but short (2 d), and NKp30 was induced to lower levels vs. healthy donors. Notably, in antiretroviral-treated aviremic progressor patients (TAPPs), no induction of NKp46 or NKp30 expression occurred. More importantly, EC/LTNP failed to induce expression of NKp44, a receptor efficiently induced in activated NK cells in TAPPs. The specific lack of NKp44 expression resulted in sharply decreased capability of killing target cells by NKp44, whereas TAPPs had conserved NKp44-mediated lysis. Importantly, conserved NK cell responses, accompanied by a selective defect in the NKp44-activating pathway, may result in lack of killing of uninfected CD4(+)NKp44Ligand(+) cells when induced by HIVgp41 peptide-S3, representing a relevant mechanism of CD4(+) depletion. In addition, peripheral NK cells from EC/LTNP had increased NKG2D expression, significant HLA-DR up-regulation, and a mature (NKG2A-CD57(+)killer cell Ig-like receptor(+)CD85j(+)) phenotype, with cytolytic function also against immature dendritic cells. Thus, NK cells in EC/LTNP can maintain substantially unchanged functional capabilities, whereas the lack of NKp44 induction may be related to CD4 maintenance, representing a hallmark of these patients.

Pregnancy outcomes following exposure to efavirenz-based antiretroviral therapy in the Republic of Congo.

WHO recently recommended efavirenz (EFV) use for HIV infection through pregnancy, breastfeeding and childbearing age. However the use of EFV during pregnancy remains of concern and not all national guidelines reflect WHO advice. Few data are available concerning pregnancy outcomes. The objective of our study was to evaluate pregnancy outcomes in a cohort of women who conceived on EFV. A retrospective, multicenter cohort study was conducted in Pointe Noire, Republic of Congo (September 2005- June 2012). The following adverse pregnancy outcomes were considered: births defects, low birth weight, premature delivery, stillbirth and abortion, stratified by antiretroviral exposure at the time of conception. During the study period, 188 women conceived on antiretrovirals: 35 (18.6%) on EFV-based regimens and 153 (81.4%) on nevirapine-based regimens. Adverse pregnancy outcomes were observed in 17/35 (48.6%, 95% CI 33.0-64.4%) women in the EFV group and in 43/153 (28.1%, 95% CI 21.6-35.7%) in the non-EFV group (p=0.019). No birth defect was observed in either group. An increased incidence of adverse pregnancy outcomes was observed in the EFV group. As WHO is promoting a widespread use of EFV also for women in childbearing age, our study emphasizes the importance of launching large prospective cohort studies investigating pregnancy outcomes in exposed women.

Effectiveness of a project to prevent HIV vertical transmission in the Republic of Congo.

OBJECTIVES: To evaluate the effectiveness of a prevention programme against the vertical transmission of HIV in a resource-limited setting and to investigate variables associated with compliance. PATIENTS AND METHODS: The Kento-Mwana project (2005-2008) provided counselling, serological and biomolecular testing and prophylaxis/therapy to HIV-positive pregnant women and their children attending four antenatal clinics in Pointe Noire, Republic of Congo. Expected and actual rates of vertical transmission of HIV were compared. Univariate and multivariate analyses were performed in order to identify variables associated with non-compliance. RESULTS: The observed transmission rate in the group who completed follow-up was 5/290 (1.7%, 95% CI 0.6%-4.1%). The overall estimated transmission rate in the target population, computed taking into account the expected vertical transmission of HIV among drop-outs, was 67-115/638 (10.5%-18.0%). A comparison between this rate and the expected transmission rate in the absence of intervention (25%-40%) showed that the programme was able to prevent approximately 50% of vertical transmissions. Older age (OR 0.33, 95% CI 0.16-0.66, P = 0.002), telephone availability (OR 0.42, 95% CI 0.24-0.72, P = 0.002) and occupation (OR 0.57, 95% CI 0.29-1.10, P = 0.092) were associated with better compliance. CONCLUSIONS: Despite the vast majority of women accepting counselling and testing, many of them refused prophylaxis or dropped out, thus reducing the effectiveness of the intervention from an ideal 2% to a still important but less impressive median transmission rate of 15% (range 10.5%-18%). Promoting participation and compliance, rather than increasing the potency of antiretroviral regimens, is crucial for preventing the vertical transmission of HIV in Africa.

Fourteen-day survival among older adults with severe infection with severe acute respiratory syndrome coronavirus 2 treated with corticosteroid: a cohort study.

OBJECTIVE: To assess the effectiveness of corticosteroids among older adults with coronavirus disease 2019 (COVID-19) pneumonia requiring oxygen. METHODS: We used routine care data from 36 hospitals in France and Luxembourg to assess the effectiveness of corticosteroids with at least 0.4 mg/kg/day equivalent prednisone (treatment group) versus standard of care (control group). Participants were adults aged 80 years or older with PCR-confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection or CT scan images typical of COVID-19 pneumonia, requiring oxygen ≥3 L/min, and with an inflammatory syndrome (C-reactive protein ≥40 mg/L). The primary outcome was overall survival at day 14. In our main analysis, characteristics of patients at baseline (i.e. time when patients met all inclusion criteria) were balanced by using propensity-score inverse probability of treatment weighting. RESULTS: Among the 267 patients included in the analysis, 98 were assigned to the treatment group. Their median age was 86 years (interquartile range 83-90 years) and 95% had a SARS-CoV-2 PCR-confirmed diagnosis. In total, 43/98 (43.9%) patients in the treatment group and 84/166 (50.6%) in the control group died before day 14 (weighted hazard ratio 0.67, 95% CI 0.46-0.99). The treatment and control groups did not differ significantly for the proportion of patients discharged to home/rehabilitation at day 14 (weighted relative risk 1.12, 95% CI 0.68-1.82). Twenty-two (16.7%) patients receiving corticosteroids developed adverse events, but only 11 (6.4%) from the control group. CONCLUSIONS: Corticosteroids were associated with a significant increase in the overall survival at day 14 of patients aged 80 years and older hospitalized for severe COVID-19.

HIV serological screening in a population of pregnant women in the Republic of Congo: suitability of different assays.

Different strategies can be applied for the screening of HIV infection, depending on the local seroprevalence. Within a WHO type III strategy, we compared the results of two different second-line methods for HIV screening of a population of pregnant women in the Republic of Congo. Sera from 3614 consecutive pregnant women were tested for HIV with Genescreen Plus Ag/Ab EIA assay; positive specimens were retested with two different second-line methods. (Determine HIV-1/2 rapid test and Vironostika HIV Ag/Ab specific EIA assay). Discordant samples were tested with HIV-1/2 Western Blot and, if necessary, HIV RNA molecular assay. Of the 3614 sera, 221 were positive with Genscreen. Among them, 21 and 10 tested negative with Vironostika and Determine, respectively. A 100% correspondence with 3rd line confirmation test results was found in Genscreen positive/Vironostika negative samples, whereas a 5.5% overestimation of HIV seroprevalence was observed when Determine, instead of Vironostika, was used as second-line test. The choice of appropriate assays in adequate sequence, within the correct WHO strategy, is pivotal to minimize the risk of overtreatment of HIV infection.

Incidence, risk factors, and predictors of outcome of candidemia. Survey in 2 Italian university hospitals.

In recent decades, Candida spp. emerged as the fourth most common cause of nosocomial bloodstream infections. The incidence of candidemia was 0.13 per 100 persons. Eighty-three cases (61%) of candidemia were due to Candida albicans and 53 (39%) to nonalbicans Candida spp. Twelve strains of Candida (9%) had shown in vitro resistance to fluconazole, 5 (4%) to itraconazole, 2 (1.5%) to voriconazole, 12 (9%) to 5-flucytosine, and 1 (0.7%) to amphotericin B. Multivariate logistic regression analysis of risk factors showed that length of hospitalization, presence of a central venous catheter, previous episodes of candidemia or bacteremia, parenteral nutrition, and chronic renal failure were variables independently associated with the development of candidemia. Multivariate logistic regression analysis of prognostic indicators showed that the independent variables associated with poor prognosis were inadequate initial therapy (P < .001) and high APACHE III score (P = .004). The inadequate initial therapy associated with mortality indicates the need for additional investigations to define high-risk patients for beneficial antifungal prophylaxis.

Prevalence of HIV-1 Subtypes and Drug Resistance-Associated Mutations in HIV-1-Positive Treatment-Naive Pregnant Women in Pointe Noire, Republic of the Congo (Kento-Mwana Project).

The Kento-Mwana project was carried out in Pointe Noire, Republic of the Congo, to prevent mother-to-child HIV-1 transmission. To determine the prevalence of different subtypes and transmitted drug resistance-associated mutations, 95 plasma samples were collected at baseline from HIV-1-positive naive pregnant women enrolled in the project during the years 2005-2008. Full protease and partial reverse transcriptase sequencing was performed and 68/95 (71.6%) samples were successfully sequenced. Major mutations to nucleoside reverse transcriptase inhibitors, nonnucleoside reverse transcriptase inhibitors, and protease inhibitors were detected in 4/68 (5.9%), 3/68 (4.4%), and 2/68 (2.9%) samples, respectively. Phylogenetic analysis of HIV-1 isolates showed a high prevalence of unique recombinant forms (24/68, 35%), followed by CRF45_cpx (7/68, 10.3%) and subsubtype A3 and subtype G (6/68 each, 8.8%). Although the prevalence of transmitted drug resistance mutations appears to be currently limited, baseline HIV-1 genotyping is highly advisable in conjunction with antiretroviral therapy scale-up in resource-limited settings to optimize treatment and prevent perinatal transmission.

Discordances with HIV-1 RNA quantitative determinations by three commercial assays in Pointe Noire, Republic of Congo.

Accurate HIV-1 RNA quantitation is required to support the scale up of antiretroviral therapy in African countries. Extreme HIV-1 genetic variability in Africa may affect the ability of commercially available assays to detect and quantify HIV-1 RNA accurately. The aim of this study was to compare three real-time PCR assays for quantitation of plasma HIV-1 RNA levels in patients from the Republic of Congo, an area with highly diversified HIV-1 subtypes and recombinants. The Abbott RealTime HIV-1, BioMérieux HIV-1 EasyQ test 1.2 and Cobas AmpliPrep/Cobas TaqMan HIV-1 1.0 were compared for quantitation of HIV-1 RNA in 37 HIV-1 seropositive pregnant women enrolled in the Kento-Mwana project for prevention of mother-to-child transmission in Pointe-Noire, Republic of Congo. The sample panel included a variety of HIV-1 subtypes with as many as 21 (56.8%) putative unique recombinant forms. Qualitative detection of HIV-1 RNA was concordant by all three assays in 33/37 (89.2%) samples. Of the remaining 4 (10.8%) samples, all were positive by Roche, three by Abbott and none by BioMérieux. Differences exceeding 1Log in positive samples were found in 4/31 (12.9%), 10/31 (32.3%) and 5/31 (16.1%) cases between Abbott and BioMérieux, Roche and BioMérieux, and Abbott and Roche, respectively. In this sample panel representative of highly polymorphic HIV-1 in Congo, the agreement among the three assays was moderate in terms of HIV-1 RNA detectability and rather inconsistent in terms of quantitation.

Successfully treated HIV-infected patients have differential expression of NK cell receptors (NKp46 and NKp30) according to AIDS status at presentation.

Differences in innate immune responses may be associated with different capabilities of controlling HIV infection, not necessarily reflected by CD4(+) T-cell counts alone. We investigated by cytofluorometry the expression of NK cell receptors and ligands in 19 treated HIV-infected patients with CD4(+)<220 ml(-1) at presentation (11 AIDS, 8 non-AIDS) and 10 healthy donors. Expression of NKp46 and NKp30 was significantly higher in non-AIDS vs. AIDS patients. Overall, the level of NKp46 expression directly correlated with the degree of NK cell cytotoxicity. As compared to healthy donors, in both groups, there was a similar increase of CD69 and HLA-DR expression in NK cells that directly correlated with the presence of activation markers (HLA-DR) on CD4(+) and CD8(+) T cells. As compared to AIDS, in non-AIDS patients in vitro activated CD4(+) showed higher expression of MIC-A (NKG2D ligand), with significantly higher Nectin-2/DNAM-1 and MIC-A/NKG2D ratios. Thus, NK cell responses in AIDS and non-AIDS patients with similar CD4(+) counts significantly differ despite similar treatment. This suggests an involvement of innate mechanisms, in preventing AIDS-defining opportunistic infections in HIV infection and further suggests, that CD4(+) absolute counts alone, may be inadequate to explain differences in the clinical outcome.

Impact of extensive HIV-1 variability on molecular diagnosis in the Congo basin.

BACKGROUND: Previous studies have shown a high HIV-1 genetic variability in the Republic of Congo. This can greatly influence the performance of molecular assays for HIV-1 diagnosis. OBJECTIVES: To define a reliable test for detection of HIV-1 DNA in this area. STUDY DESIGN: We compared a commercial nested PCR (C-PCR) assay and an in house nested PCR (H-PCR) assay for the detection of HIV-1 DNA in the first 30 seropositive pregnant women enrolled into the ongoing "Kento-Mwana" project, for the prevention of HIV mother-to-child transmission in the city of Pointe Noire, Republic of Congo, Africa. Sequencing and phylogenetic analysis of partial HIV-1 pol sequences were also performed. RESULTS: C-PCR detected HIV-1 DNA in only 15/30 samples from seropositive women (50.0%), as opposed to 29/30 (96.6%) by H-PCR (P<0.0001). Phylogenetic analysis and bootscanning showed that only 10 sequences could be assigned to known clades (seven pure subtypes and three circulating recombinant forms), whereas the other 20 sequences were unique recombinant forms. CONCLUSIONS: The great genetic variability of HIV-1 in this area strongly advises to for using molecular methods only after local validation to avoid false negative results.