Tissue and serum immune response in chronic hepatitis C with mild histological lesions

The immunopathogenesis of chronic hepatitis C virus (HCV) infection is a matter of great controversy and has been suggested to involve a complex balance between cytokines with pro and anti-inflammatory activity. We investigated the expression of inflammatory cells and cytokines in the liver and serum of 51 chronically HCV infected patients and compared them to data from two sets of normal controls: 51 healthy blood donors and 33 liver biopsies of healthy liver donors. We also assessed the relationship between selected cytokines and cell populations in hepatic compartments and the disease stage. Compared with controls, hepatitis C patients had a greater expression of portal TNF-á, TGF-â and CD4+ and acinar IFN-ã, TNF-á, IL-1â and IL-4, as well as a higher serum concentration of IL-2, IL-10 and TGF-â. Significant positive correlations were found between portal CD4+ and TNF-á, portal CD8+ and TGF-â, portal CD45+RO and TNF-á, acinar CD45+RO and IFN-ã and acinar CD57+ and TGF-â. In conclusion, we have shown that (i) in this sample of predominantly mild disease, the immune response was associated with a pro-inflammatory response pattern, (ii) CD4+ T-lymphocytes played a major role in orchestrating the immune response and (iii) these events primarily took place in the portal space.

Immunopathology of the duodenal mucosa of HIV-positive patients during combined antiretroviral therapy

The objective of the present study was to evaluate the duodenal mucosa of HIV-infected patients during antiretroviral therapy. This was an observational study conducted on HIV-positive patients and a control group. Group 1 comprised 22 HIV-negative individuals while 38 HIV-positive individuals were classified according to the CDC 1993 classification into group 2 (A1 or A2) or group 3 (B2, A3, B3, C2, C3). All subjects were submitted to upper gastrointestinal endoscopy with duodenal biopsies. Qualitative, semi-quantitative and quantitative histological analyses were performed. Results were considered significant when P < 0.05. A higher prevalence of inflammatory infiltrate and eosinophilia was observed in the HIV group, together with a reduction in mucosal CD4+ lymphocyte (L) counts [median (lower-upper quartiles), 12.82 (8.30-20.33), 6.36 (1.75-11.66) and 1.75 (0.87-3.14) in groups 1, 2 and 3, respectively] which was not correlated with disease stage. The extent of CD4+L count reduction was similar in blood and duodenal mucosa. Normal CD8+L and CD45RO+L counts, and normal numbers of macrophages and antigen-presenting cells were also found in the HIV patients. The cytokine pattern did not differ among groups. Tissue HIV, assessed by p24 antigen, correlated with a higher CD45RO+L count (77.0 (61-79.8) and 43.6 (31.7-62.8) in p24+ and p24-, respectively, P = 0.003), and IL-4 positivity (100 and 48.2 percent in p24+ and p24-, respectively, P = 0.005). The duodenal mucosa of HIV+ patients showed a relatively preserved histological architecture. This finding may be characteristic of a population without opportunistic infections and treated with potent antiretroviral therapy, with a better preservation of the immune status.

Pattern of mycobaterial antigen detection in leprosy

Foi realizada reacao imunohistoquimica (Peroxidase anti-peroxidase-PAP) em 52 biopsias de pele de pacientes com hanseniase com o objetivo de verificar quais os padroes antigenicos das micobacterias e estudar a sensibilidade deste metodo como auxilio diagnostico da hanseniase. Foram encontrados cinco padroes diferentes, classificados como bacilar, granular, vesicular, citoplasmatico e depositos, de acordo com a caracteristica do material antigenico. Os depositos (material finamente particulado) apareceram com maior frequencia confirmando a sensibilidade da imunohistoquimica na deteccao de pequenas quantidades de antigeno, cujo material nao e mais visto por coloracoes histoquimicas usuais.