Molecular epidemiology of human immunodeficiency virus type 1 and therapeutic monitoring of patients treated in Kinshasa/Democratic Republic of the Congo

Author(s): Erick Ntambwe Kamangu*, Roger Di-Mosi Wumba, Hippolyte Nani-Tuma Situakibanza, Prosper tshiloba Lukusa, Liévin kalala Kapend, Georges lelo Mvumbi, Marie-pierre Hayette and Richard lunganza Kalala

Context: The introduction of Antiretroviral Drugs (ARVs) has reduced morbidity and mortality associated with the Human Immunodeficiency Virus (HIV) infection. But also at the other hand, the massive use of these molecules created the emergence of mutant strains resistant to the treatment.

Objective: The objective set for this study was to determine the different variants of HIV-1 group M circulating in Kinshasa, the prevalence of mutations associated with resistance to antiretroviral treatment and their involvement in therapeutic monitoring of infected patients followed in different centers.

Methods: A prospective cohort study conducted in collaboration with 8 centers in Kinshasa from August 2013 to October 2014. One hundred fifty-three (153) subjects diagnosed positive for HIV Type 1 by serology voluntarily and naïve of treatment participated in this controlled study. Five milliliters (5 ml) of blood were collected in a tube with anticoagulant EDTA. The DNA was extracted from 200 μl of Buffy Coat using the QIAamp DNA Blood Mini Kit QIAGEN^® and RNA was extracted from 140 μl of plasma using the QIAamp RNA Mini Kit QIAGEN^®. A Quantitative PCR was performed to determine the Viral Load for all samples. A Reverse Transcription PCR (RT-PCR) and Nested PCR were performed to amplify the regions of interest for the Protease and Reverse Transcriptase (RT) for sequencing.

Results: One hundred and fifty three (153) patients infected with HIV Type 1 were selected for this work. The population consisted of 61 (39.9%) men and 92 (60.1%) women. The median age was 37 years with extremes of 18 and 65 years. The median values of Viral Loads and rate of CD4 lymphocytes at baseline were respectively 5.68 log10 RNA copies/ ml and 180 cells/ml. The subtype A is dominant with 35 cases (22.9%); followed by CRF02_AG (11.1%), C (9.8%), G (9.8%), K (9.8%), D (7.8%), H (7.8%) and J (5.0%). The most significant observed Major mutations were: L90M (2.0%), D30N (1.3%), V32I (1.3%), V82A (1.3%) and I84V (1.3%). The most frequent observed mutations for NRTI were: V75I/N/L/M (18.3%), K70E/N/R (9.8%), D67G/E/N (9.2%), M184V/L/K/R (9.2%) and T215F/N/I/L (9.2%). The most frequent mutations for NNRTI were: V179F/T/D (9.8%), K103N/I/R (8.5%), V106I/A (7.2%), Y181K/C (5.8%) and V90I/GIS (5.8%). At the 6^th month of ART (M6), 138 patients (90.2%) including 81 women (58.7%) and 57 men (41.3%) returned to their control. The median values of CD4 and VL of patients are respectively 480 cells/ ml and 0.90 log10 RNA copies/ml. Thirty-four patients (24.6%) were in virological failure.

Conclusion: This study demonstrates a strong diversity of HIV-1 in Kinshasa, which is dominated by the subtype A and CRF02_AG, and several resistances associated with the treatment detected in patients naïve of treatment. The 6^th month of treatment, the rate of virological treatment failure was of 24.6% which is highly correlated with transmitted mutations at baseline.

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