[Frequency of the mutated allele of CCR-5 receptor in HIV-1 positive and negative individuals in the Province of Chaco]. / Frecuencia del alelo mutado del receptor CCR-5 en individuos HIV-1 positivos y negativos en la provincia del Chaco.

The importance of chemokine receptors in the pathophysiology of HIV infection became apparent when it was demonstrated that persons at high risk for HIV-1 infection remain uninfected when they carry a polymorphic variant of CCR5. In individuals who are homozygous for the 32 base-pair deletion in the CCR5 gene, a functional protein cannot be synthesized and such persons are not found in HIV-1 positive cohorts. Furthermore, in individuals heterozygous for that mutation, there is an association with slow disease progression. The mutant allele of CCR-5 is present at high frequency in the Caucasian population, but is absent in the Japanese and black populations. The aim of this study was to assess the frequency of the truncated allele of CCR-5 gene in the cohort of HIV infected and non-infected subjects in the Province of Chaco, Argentina (with Guaraní and Hispanic genetic background). A total of 118 unrelated seronegative healthy blood donors and 80 seropositive HIV-1 subjects were studied. A portion of CCR-5 gene from genomic DNA was amplified by PCR and analyzed on a 3% agarose gel. The frequency of the delta CCR-5 allele was 2.5% for homozygous and 15.3% for heterozygous seronegative subjects, similar to that reported in the Caucasian population; the homozygous CCR-5 allele was absent in HIV-1 positive patients and the frequency of heterozygous was 2.5%, significantly lower than reported in the Caucasian population.

Frecuencia del alelo mutado del receptor CCR-5 en individuos HIV-1 positivos y negativos en la provincia del Chaco. / [Frequency of the mutated allele of CCR-5 receptor in HIV-1 positive and negative individuals in the Province of Chaco]

The importance of chemokine receptors in the pathophysiology of HIV infection became apparent when it was demonstrated that persons at high risk for HIV-1 infection remain uninfected when they carry a polymorphic variant of CCR5. In individuals who are homozygous for the 32 base-pair deletion in the CCR5 gene, a functional protein cannot be synthesized and such persons are not found in HIV-1 positive cohorts. Furthermore, in individuals heterozygous for that mutation, there is an association with slow disease progression. The mutant allele of CCR-5 is present at high frequency in the Caucasian population, but is absent in the Japanese and black populations. The aim of this study was to assess the frequency of the truncated allele of CCR-5 gene in the cohort of HIV infected and non-infected subjects in the Province of Chaco, Argentina (with Guaraní and Hispanic genetic background). A total of 118 unrelated seronegative healthy blood donors and 80 seropositive HIV-1 subjects were studied. A portion of CCR-5 gene from genomic DNA was amplified by PCR and analyzed on a 3

agarose gel. The frequency of the delta CCR-5 allele was 2.5

for homozygous and 15.3

for heterozygous seronegative subjects, similar to that reported in the Caucasian population; the homozygous CCR-5 allele was absent in HIV-1 positive patients and the frequency of heterozygous was 2.5

, significantly lower than reported in the Caucasian population.

[Spontaneous chagasic peritonitis in a patient with AIDS]. / Peritonitis espontánea chagásica en un enfermo de Sida.

An AIDS-Chagas association has been extensively reported in the literature specially in cardiac and cerebral localizations. A case is presented of a 36 year old male patient with a diagnosis of AIDS and positive serology for Chagas, as well as chronic hepatopathy and CD4 cell count of 31. While in the hospital he developed ascitis which revealed the presence of numerous tripomastigote forms of T. cruzi in the ascitic fluid. This clinical presentation of Chagasic reactivation has not been reported in the literature.

[Anti-neutrophil cytoplasmic antibodies (ANCA) in patients with symptomatic and asymptomatic HIV infection]. / Anticuerpos anticitoplasma de neutrófilos (ANCA) en pacientes infectados por HIV sintomáticos y asintomáticos.

The cytopathic effect of HIV on CD4 T cells, as well as the active autoimmune mechanism occurring during infection, have been documented. Of the cytokines involved in the pathogenesis of AIDS, the main one produced by the monocyte-macrophage series is tumor necrosis factor alfa (TNF alpha). This cytokine induces antigens such as proteinase 3 (Pr 3) or mieloperoxidase (MPO). Anti-neutrophil cytoplasmic antibodies (ANCA) are directed against this type of PMN antigens. In the present paper, the role of anti-neutrophil cytoplasmic antibodies (ANCA) in HIV infected patients as responsible for autoimmune phenomena in relation to opportunistic infections, was studied. A total of 88 serum samples belonging to 49 asymptomatic and 39 symptomatic HIV infected patients were tested for ANCA by an indirect immunofluorescence (IIF) test over a neutrophil substrate. ANCA were detected in 53.8% of symptomatic patients as compared to 4.1% in asymptomatic cases (p < 0.0001). A 95.9% correlation was observed between ANCA-positive samples and pulmonary infection (n = 20). In those ANCA (+) samples 95.9% correlation was found with pulmonary infection (n = 20). Pulmonary infection due to Mycobacterium tuberculosis is a frequent finding in HIV infected patients from Northeastern Argentina. When the presence of ANCA in TB(+) HIV(+) and TB(+) HIV(-) patients was studied, it was seen that positive-ANCA significantly correlated with the first group (p < 0.001). The presence of ANCA was not related to viral infections, toxoplasmosis, neurological features of AIDS, vasculitis or malignant diseases. ANCA during pulmonary infection, mostly caused by TB, as well as PMN infiltration in pulmonary parenchyma, and the deregulated immune reaction elicited by HIV, may contribute to the onset of autoimmune phenomena. The presence of human T lymphocytes reactive to heat stress proteins (Hsp), an important target of immune response against certain intracellular auto-antigens such as MPO from PMN, added to the mechanism of molecular mimicry, could explain the association of ANCA and TB in patients with severe alterations of their immune response. According to these results, the limited presence of ANCA in asymptomatic patients HIV(+) and in HIV(-) with pulmonar TB, could indicate that the virus may not be responsible for the induction of these antibodies.