Molecular Detection and Clinical Implications of HTLV-1 Infections among Antiretroviral Therapy-Naïve HIV-1-Infected Individuals in Abuja, Nigeria

Abstract

BACKGROUNDIndividuals with human T-cell lymphotrophic virus type-1 (HTLV-1)/HIV-1 coinfection have been demonstrated to undergo CD4+ lymphocytosis even in the face of immunodeficiency and increased vulnerability to opportunistic pathogens that can lead to poor prognosis.OBJECTIVEThis study investigated the prevalence as well as the effects of HIV-1/HTLV-1 coinfection on CD4+ cell counts, routine hematology, and biochemical parameters of study participants.MATERIALS AND METHODSThis prospective cross-sectional study involved 184 blood samples collected from HIV-1-seropositive individuals attending HIV-special clinic of the University of Abuja Teaching Hospital, Gwagwalada, Nigeria. These samples were analyzed for anti-HTLV-1/2 IgM antibodies using enzyme-linked immunosorbent assay, CD4+ cell counts, and some routine hematological and biochemical parameters. All samples were also tested for HTLV-1 provirus DNA using real-time polymerase chain reaction (PCR) assay.RESULTSOf the 184 subjects studied, 9 (4.9%) were anti-HTLV-1/2 IgM seropositive; however, upon real-time PCR testing, 12 (6.5%) had detectable HTLV-1 provirus DNA. The CD4+ cell count was significantly high in HTLV-1-positive (742 ± 40.2) subjects compared to their HTLV-1-negative (380 ± 28.5) counterpart (P-value = 0.025). However, there was no significant association between HTLV-1 positivity with other hematology and biochemical parameters studied (P > 0.05).CONCLUSIONAll subjects (100%) who were HTLV-1/HIV-1-coinfected had normal CD4+ counts. This gives contrasting finding on the true extent of immunodeficiency of subjects. So it is suggested to be very careful in using only CD4+ counts to monitor disease progression and as indicators for antiretroviral therapy (ART) in resource-limited settings. In such conditions, there may be a need to test for HTLV-1 alongside HIV viral loads in order to begin appropriate ART regimens that contain both pathogens.

Assessment of risk factors associated with HTLV-1/-2 infection among people living with HIV/AIDS in Bauchi State, Nigeria

“…In our study, the highest prevalence of anti-HTLV-1/-2 IgG was highest among subjects within 15-24 years (20.0%) and least among those within 24-35 years (4.2%). This agreed with findings of Nasir et al [11] who reported the highest prevalence of HTLV-1 among the age group 21-30 years. This could be because this population age range represents the leading sexually active age group in Nigeria.…”

“…The prevalence rate of 19.8% for recent HTLV-1/-2 infection in HIV/AIDS patient reported in this study was lower than 25.7% HTLV −1/-2 IgM seroprevalence reported by Adeoye et al [6]. However, IgM seroprevalence was significantly higher than 4.9% seroprevalence of HIV-1/HTLV co-infection in Abuja [11], and 1.8% HTLV/HIV-1 coinfection in KwaZulu-Natal by Rego et al [14] and 5.2% HTLV/ HIV coinfection prevalence in Guinea-Bissau [15]. The difference is most likely due to the difference in the laboratory protocol in detecting HTLV.…”

“…A seroprevalence of 4.9% HTLV-1 was reported in the study on ART-naïve HIV infected attending the University of Abuja Teaching Hospital [11]. However, the study did not differentiate the various categories of infection using IgG and IgM and did not determine risk factors associated with the HIV/HTLV coinfections.…”

“…The subjects were divided into two study groups viz; 80 (44.0%) ART-naïve and 102 (56.0%) ARTexperienced. The sample size was determined from a previous cross-sectional study that reported 4.9% seroprevalence of HTLV among HIV infected person in Abuja, Nigeria [11], a minimum sample size of 73 was calculated. However, to improve the statistical credence of the study, the size was increased to 182 voluntary participants.…”

HTLV-1, ATLL, severe hypercalcaemia and HIV-1 co-infection: an overview

“…The triad presentation of HTLV-1, ATLL and severe/refractory hypercalcaemia has been described in case reports [ 6 - 9 ]. However, the true prevalence of this presentation is unknown, largely due to misdiagnosis and underreporting as HTLV-1 is seldom considered for investigation in HIV infected individuals [ 10 ]. Current areas of uncertainty surrounding HTLV-1 co-infection include its impact on the progression of HIV disease and the initiation of antiretroviral therapy in countries where access to these drugs are restricted [ 3 , 11 ].…”