Manifestações neurológicas e características imunológicas da coinfecção pelos vírus da imunodeficiência humanatipo 1 e vírus linfotrópico humano de células tipo 1

Abstract

INTRODUCTION: HIV-1/HTLV-1 coinfection occurs in about 10% to 16.3% of the Brazilian HIV-1infected population. Human retroviruses exhibit tropism for nervous tissue but little is known about the immune mechanisms of the spinal cord injury observed in HTLV- 1/HIV-1 co-infection. Cytokines and chemokines are important inflammatory mediators and should be involved on the occurrence of myelitis. To our knowledge, no studies on chemokines have been published in co-infected individuals. OBJECTIVE: To compare the neurological manifestations and immunological characteristics of HIV-1/HTLV-1 coinfected individuals with control subjects (blood donors), monoinfected by HTLV-1 and HIV-1. METHODS: This is a descriptive cross-sectional study of 16 coinfected patients (HIV- 1/HTLV-1), 20 blood donors, 56 infected by HTLV-1 and 49 by HIV-1. Volunteers in the study groups were submitted to neurological examination, dosage of cytokines and chemokines by Cytometric Bead Array technique (CBA) and HTLV-1 proviral load. Other tests included blood T CD4+ cell counts, viral load, serology for viral hepatitis B and C and syphilis. For statistical analysis the SPSS package and the GraphPad Prism were used. The serum levels of cytokines and chemokines were measured and the individuals were classified as high and low producers. We considered high-producer individuals those who presented serum cytokines and chemokines levels above the median value of the blood donors. RESULTS: The prevalence of HTLV-1 coinfection in HIV-1 infected subjects was of 2.6%. A higher frequency of tinnitus, urinary incontinence, difficulty in climbing stairs and the presence of the Romberg sign was described in coinfected individuals. The occurrence of myelopathy did not differ between the coinfected and the monoinfected HTLV-1 group (p=0.918). The mean T CD4+ cell count was higher in the coinfected group (p=0.014). There was no difference in the proviral load (HTLV-1) and viral load (HIV-1) between the study groups. Higher serum TNF- and decreased IL-4 and CCL5/RANTES were found in the coinfected group as compared to the HTLV-1 group and lower levels of IFN- and IL-4 as compared to the HIV-1 group. High-producers analysis revealed that the IL-6 levels weresimilar among the three study groups. CONCLUSION: The coinfected individuals presented a higher frequency of tinnitus, difficulty in climbing stairs, urinary incontinence and the Romberg sign. Higher serum TNF- and decreased IL-4 and CCL5/RANTES were found in the coinfected group as compared to the HTLV-1 group and lower levels of IFN- and IL-4 as compared to the HIV-1 group.