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.

SUMMARY -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.KEY WORDS: HTLV-I/II, uveitis, myelopathy, spastic paraparesis, Sjögren's syndrome.Uveite, mielopatia, artrite reumatóide e sfndrome de Sjogren associadas ao HTLV-I RESUMO: Uma mulher branca de 62 anos foi internada apresentando história de paraparesia lentamente progressiva durante 10 anos. Dois meses antes da internação ela apresentou uveíte anterior não granulomatosa bilateral. Poucos anos após o início dos sintomas neurológicos, ela desenvolveu artrite migratória com edema dos joelhos e dor a palpação dos joelhos e dedos dos pés, boca, pele e olhos secos. Ao exame físico foi observado paraparesia espástica com sinal de Babinski positivo, sensibilidade diminuída abaixo de L3, diminuição da sensação de vibração nas extremidades inferiores, e tremor postural dos membros superiores. Apresentou testes positivos para o HTLV-I no sangue. O estudo do líquido cefalorraquidiano mostrou discreta pleocitose, proteínas normais e ELISA e Western blot positivos para o HTLV-I. O estudo da velocidade de condução dos nervos foi normal. Este caso mostra a associação de uveíte, artrite e síndrome de Sjogren em uma paciente com paraparesia espástica tropical (HTLV-I) associada a mielopatia (TSP/HAM), e ilustra o largo espectro das manifestações clínicas que podem acompanhar a infecção por este vírus. PALAVRAS-CHAVE: HTLV-I/II, uveite, mielopatia, paraparesia espástica, síndrome de Sjogren.Human T-lymphotropic virus type I (HTLV-I), a retrovirus causing adult T-cell leukemia (ATL) and lymphoma, has been also considered as an etiologic agent of a form of a chronic progressive myelopathy (TSPI HAM) occurring most commonly in some tropical countries and Japan 16,20,22,23 . It has been also found in association with acute granulomatous or nongranulomatous uveitis, then

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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.

-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.KEY WORDS: erectile insufficiency, HTLV-I/II infection, myelopathy, HAM/TSP, Brazil.

The clinical and public health importance of indeterminate results in HIV-(1/2) testing is still difficult to evaluate in volunteer blood donors. At Fundacao Hemominas, HIV-(1/2) ELISA is used as the screening test and, if reactive, is followed by Western blot (WB). We have evaluated 84 blood donors who had repeatedly reactive ELISA tests for HIV-(1/2), but indeterminate WB results. Sixteen of the 84 donors (19.0%) had history of sexually transmitted diseases; 18/84 (21.4%) informed receiving or paying for sex; 3/84 (3.6%) had homosexual contact; 2/26 women (7.6%) had past history of multiple illegal abortions and 3/84 (3.6%) had been previously transfused. Four out of 62 donors (6.5%) had positive anti-nuclear factor (Hep2), with titles up to 1:640. Parasitological examination of the stool revealed eggs of S. mansoni in 4/62 (6.4%) donors and other parasites in 8/62 (12.9%). Five (5.9%) of the subjects presented overt seroconversion for HIV-(1/2), 43/84 (51.2%) had negative results on the last visit, while 36/84 (42.9%) remained WB indeterminate. Although some conditions could be found associated with the HIV-(1/2) indeterminate WB results and many donors had past of risky behavior, the significance of the majority of the results remains to be determined.

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