Expresión de proteínas del choque térmico HSP72 y HSP73 en casos colombianos de Linfoma de Hodgkin positivos y negativos para virus de Epstein Barr / Expression of heat shock proteins HSP72 and HSP73 in Epstein-Barr positive or negative Hodgkin lymphoma

Background: The expression of heat shock proteins (HSP70) in tumor cells or virus infected cells is important for the induction of specific cellular immune response. They are implicated in transport of immunodominants peptides in the endoplasmic reticulum, activation of antigen presenting cells and cross priming of CD8 T cells. Aim: To analyze the expression of HSP70 protein in its constitutive (HSP73) and inducible forms (HSP72) in Hodgkin's lymphoma (HL), infected or not by Epstein Barr virus (EBV) and to assess its relationship with pathological subtype, clinical stages and treatment response. Material and methods: The analysis of HSP73 and HSP72 was done by immunoperoxidase on routinely processed paraffin sections with prior antigen retrieval. Results: Sixty seven cases were studied. The expression of HSP73 and HSP72 was detected in 19.4 and 17.9% of samples respectively. The infiltrating lymphocytes expressed HSP72 in 58% of cases. The pathological subtypes with the higher expression in lymphocytes were mixed cellularity and nodular sclerosis. No differences in HSP70 expression were observed, according to clinical stage, treatment response or the presence of EBV. Conclusions: The expression of HSP72 on lymphocytes suggests that this protein plays an important role in the induction and amplification of anti-tumor immune response (Rev Méd Chile 2003; 131: 1375-81).

Los genotipos de helicobacter pylori en gastritis no atrófica difieren de los encontrados en úlcera péptica, lesiones premalignas y cáncer gástrico en Colombia / Helicobacter pylori genotypes in non atrophic gastritis, peptic ulcer disease, premalignant lesions and gastric cancer in Colombia

Background: Helicobacter pylori is recognized as an etiologic agent of several gastric diseases. Bacterial genotypes have been related to clinical outcome in several populations. Aim: To compare cagA, vacA and iceA genotypes of Colombian isolates from patients with several gastrointestinal diseases, including gastric cancer. Material and methods: We used polymerase chain reactions to amplify vacA, cagA and iceA genes of 137 H pylori isolates coming from 26 patients with gastric cancer (GC), 34 with peptic ulcer (PU), 19 with intestinal metaplasia (IM), 23 with atrophic gastritis (AG) and 35 with non atrophic gastritis (NAG). Results: vacA s1-m1, cagA+, iceA+ were the most frequently found genotypes. vacA s1 and m1 subtypes were found in 92 (67 percent) and 82 (60 percent) cases respectively. Sixty three percent were cagA+ and 85 percent were iceA+. There was a lower prevalence of s1 allele in cases of NAG (43 percent), compared with GC, PU and IM (81 percent, 77 percent and 81 percent prevalence, respectively, p <0.01). Isolates from NAG also showed a low frequency of vacA m1 subtype (40 percent) compared with GC or IM (81 percent and 84 percent respectively, p <0.01). The prevalence of cagA+ strains was significantly higher in GC patients (80 percent) than in NAG patients (51.4 percent, p <0.01). No differences in the frequency of vacA s1a, s1b and iceA subtypes, were observed. Conclusions: A lower frequency of cytotoxic H pylori genotypes such as cagA and vacA s1m1 and a higher frequency of non cytotoxic genotypes, was observed in patients with NAG, when compared to patients with GC or PU. These results suggest that even in Colombia, vacA and cagA could be used as markers of increased virulence