Difficulties in the diagnosis of HTLV-2 infection in HIV/AIDS patients from Brazil: comparative performances of serologic and molecular assays, and detection of HTLV-2b subtype

Abstract

The current diagnosis of human T-lymphotropic virus type-2 (HTLV-2) infection is based on the search of specific antibodies; nevertheless, several studies conducted in Brazil pointed deficiencies of the commercially available kits in detecting HTLV-2, mostly in HIV/AIDS patients. This study searched for the presence of HTLV-1 and -2 in 758 HIV/AIDS patients from Londrina, Paraná, Brazil. Serum samples were screened for HTLV-1/2 antibodies using two EIA kits (Vironostika and Murex), and confirmed by WB (HTLV Blot 2.4, Genelabs). The results obtained by EIA disclosed 49 (6.5%) reactive sera: 43 positive by both EIA kits, and six with discordant results. WB confirmed HTLV-1 infection in seven samples (0.9%) and HTLV-2 in 21 sera (2.8%). Negative and indeterminate results were detected in four (0.5%) and 16 (2.1%) sera, respectively. Blood from 47 out of 49 HTLV seroreactive patients were collected and analyzed for the presence of env, LTR and tax genomic segments of HTLVs by PCR. PCR confirmed six cases of HTLV-1 and 37 cases of HTLV-2 infection (14 out of 16 that were found to be WB indeterminate). Restriction analysis of the env PCR products of HTLV-2 disclosed 36 isolates of HTLV-2a/c subtype, and one of HTLV-2b subtype. These results emphasize the need of improving serologic tests for detecting truly HTLV-2 infected patients from Brazil, and confirm the presence of HTLV-2b subtype in the South of this country.

Human T-Lymphotropic Virus Type 1 and Type 2 Seroprevalence, Incidence, and Residual Transfusion Risk Among Blood Donors in Brazil During 2007–2009

“…A previous study with PCR analysis of samples from HIV-positive patients from southern Brazil suggested that viral lysate EIAs were less sensitive for HTLV-2, and WB gave indeterminate results for HTLV-2 (particularly subtype 2-b) in Brazil. 28 So it is possible that some HTLV-2-infected individuals may not have been detected by the EIAs used in our studies and that some of our WB indeterminates were actually infected with HTLV-2, collectively leading us to underestimate the prevalence of that infection. However, due to differences in the Brazilian region and blood donors versus the HIV patient population, we believe that HTLV-2 prevalence in our study would be only minimally affected by this issue.…”

Short Communication: Current Prevalence and Risk Factors Associated with Human T Lymphotropic Virus Type 1 and Human T Lymphotropic Virus Type 2 Infections Among HIV/AIDS Patients in São Paulo, Brazil

“…For example, the majority of HIV/ HTLV-coinfected individuals from Salvador, Bahia (northeast Brazil) are HIV/HTLV-1 coinfected, 5,6 while in Londrina, Paraná (southeast Brazil), the majority are HIV/ HTLV-2 coinfected. 20 These differences are probably due to the genetic backgrounds of the populations who colonized these regions and to the different categories of HTLV exposure. Because São Paulo (the largest city in Latin America) has a mixed population and continuously receives migrants and immigrants from all foreign countries, both HTLV-1 and HTLV-2 circulate in this region.…”

Molecular epidemiology of HIV, HBV, HCV, and HTLV-1/2 in drug abuser inmates in central Javan prisons, Indonesia

“…For HTLV-1/2 molecular detection, nucleic acids were extracted from peripheral mononuclear blood cells (PBMCs). The LTR regions of the HTLV-1 genome were amplified using the primers LTR1/LTR3 in the first round and LTR1/LTR2 in the second round [23]. The LTR regions of the HTLV-2 genome were amplified using the primers VS1/VS2 in the first round and VS3/VS4 in the second round [23].…”

“…The LTR regions of the HTLV-1 genome were amplified using the primers LTR1/LTR3 in the first round and LTR1/LTR2 in the second round [23]. The LTR regions of the HTLV-2 genome were amplified using the primers VS1/VS2 in the first round and VS3/VS4 in the second round [23]. Appropriate internal amplification controls were included in all of molecular assays to exclude the false negative results.…”