Erectile insufficiency as first symptom of HTLV I/II associated myelopathy. Case report.

A case of HTLV-I/II myelopathy in which the initial complaint was erectile insufficiency (EI) is reported. The only abnormalities found on the neurological exam were discrete weakness of the psoas and increased knee jerk reflexes. Diagnosis was made by demonstrating antibodies anti-HTLV I/II in the serum and cerebrospinal fluid (with the techniques of ELISA and Western blot), with confirmation by the polymerase chain reaction (PCR). EI can thus be the first symptom of HTLV-I/II infection and patients with EI of unknown etiology should be tested for HTLV-I/II in endemic areas.

HIV-1 detection and subtyping by PCR and heteroduplex mobility assay in blood donors: can these tests help to elucidate conflicting serological results?

Testing blood donors for the human immunodeficiency viruses (HIV-1 and 2), requires serological tests that are frequently inconclusive. Peripheral blood mononuclear cells of 50 blood donors with the screening test (ELISA) reactive to HIV-1, but with indeterminate results in the first Western Blot (WB) performed, were submitted to the polymerase chain reaction (PCR) and heteroduplex mobility assay (HMA), a nonsequencing method that can distinguish between HIV-1 subtypes (A to I). PCR amplification of HIV-1 env gene regions has been obtained in 12 (24.0%) samples. HMA of the amplified DNA showed that 12 belonged to HIV-1 B subtype and one to F subtype. PCR testing of the amplified DNA helped to elucidate doubtful serological results and HMA proved to be a relatively simple and rapid way of subtyping HIV-1 for epidemiological purposes.

Presence of human immunodeficiency virus (HIV) and T-lymphotropic virus type I and II (HTLV-I/II) in a haemophiliac population in Belo Horizonte, Brazil, and correlation with additional serological results.

The aim of this study was to determine the prevalence of human immunodeficiency virus type 1 (HIV-1) and human T lymphotropic virus types I and II (HTLV-I/II) infections in 226 haemophiliac patients treated at Fundação Hemominas in Belo Horizonte, Minas Gerais State, Brazil, and to verify association with other serological results. Patients positive for HTLV-I/II had also a neurological, haematological and ophthalmological evaluation. Fundação Hemominas offers comprehensive care for all haemophiliac patients in Minas Gerais. Thirty-six (15.9%) of the 226 patients showed reactive results to HIV-1 [ELISA, Abbott, USA, confirmed by Western blot (WB), Cambridge Biotech, USA, and/or immunofluorescence, Fiocruz, Brazil] and 16 (7.1%) had reactive sera to HTLV-I/II (ELISA, Ortho). Eleven of these 16 (4.9%) were positive, 3/16 (1.3%) were indeterminate and 2/16 (0.9%) were negative in the HTLV WB (Cambridge Biotech). Neurological, haematological and ophthalmological examination of 9/16 patients revealed no abnormality suggestive of HTLV disease. Of the 16 patients reactive to HTLV-I/II ELISA test, six (37.5%) were also positive to HIV-1 (chi 2 = 5.92; P = 0.01). Seropositivity for HTLV-I/II and HIV-1 was associated with advancing age and positive results for hepatitis C virus (HCV), Chagas' disease (T. cruzi infection) and syphilis. No association between the presence of HTLV with type and severity of haemophilia and hepatitis B results was detected. The prevalence of antibodies against HIV-1 is approximately three times that of HTLV-I/II and a patient positive for HTLV-I/II had a significantly increased risk of being positive for HIV-1, HCV and T. cruzi.

HTLV-I associated uveitis, myelopathy, rheumatoid arthritis and Sjögren's syndrome.

A 62 year-old white female presented with a 10-year-history of slowly progressive spastic paraparesis, pain and dysesthesia in the lower limbs and sphincter disturbance. A few years after the onset of the neurologic symptoms she developped migratory arthritis with swelling of the knees and pain on palpation of knees and fingers, dry eyes, mouth and skin. Two months before admission she presented bilateral nongranulomatous anterior uveitis. Examination revealed spastic paraparesis with bilateral Babinski sign, a decreased sensation level below L3, decreased vibration sense in the lower extremities, and a postural tremor of the upper limbs. Laboratory work-up disclosed HTLV-I positive tests in the blood and cerebrospinal fluid (CSF), and a mild pleocytosis in the CSF with a normal protein content. Nerve conduction velocity studies were normal. The present case shows the association of uveitis, arthritis and Sjögren's syndrome in a patient with tropical spastic paraparesis/human T-cell lymphotropic virus type I (HTLV-I) associated myelopathy (TSP/HAM), and illustrates the wide spectrum of clinical manifestations which may accompany this infection with this virus.

Antibody-dependent cell cytotoxicity against Trypanosoma cruzi is only mediated by protective antibodies.

The antibody-dependent cell cytotoxicity (ADCC) to Trypanosoma cruzi blood forms (Btry) using non-adherent spleen cells is only mediated by sera from chronic chagasic patients or mice. Both display 'lytic antibodies' (LA), which are immunoglobulins directed against epitopes only present in living BTry, and 'conventional serology antibodies' (CSA), which are responsible for the positive diagnostic tests in Chagas disease. Sera from mice immunized with different T. cruzi antigens or from treated patients (displaying only CSA but not LA) are unable to mediate ADCC. These data confirm the central role played by LA in the host resistance against T. cruzi. Moreover, they probably explain why most immunizing agents used as vaccines in Chagas' disease and which elicit CSA but not LA, do not display significant protection against T. cruzi. We also demonstrate that trypsinization of BTry increases significantly the rate of parasite destruction by ADCC, suggesting that enzyme sensitive membrane components may help BTry to evade from this immune effector mechanism.