Transmission of HCV infection among long-term hospitalized onco-haematological patients.

Hepatitis C virus (HCV) infection is becoming a substantial problem in long-term hospitalized patients. Onco-haematological patients undergoing chemotherapy are especially prone to HCV infection. These patients are usually immunosuppressed and therefore antibodies to HCV are not produced despite the presence of HCV RNA in peripheral blood. The aim of the study was to see how often long-term hospitalized patients acquired HCV infection, and what were the possible sources and routes of virus transmission. The study involved 129 children with lymphoproliferative diseases, 36 patients with solid tumours, and 61 healthcare workers from onco-haematological wards. All were HCV RNA and anti-HCV negative at the time of first hospitalization. During a two and a half-year follow-up study among 165 onco-haematological patients, HCV RNA appeared in 87 in subsequent hospitalizations. The majority of infections were (82/87) were 1a genotype, 2 were 1b, 1 was 1a + 1b and 1 was 1a + 3a. In an attempt to establish the origin of HCV infection, healthcare workers were screened for HCV genotyping. All HCV-infected staff working on wards had the same genotype (1a). None of the staff was infected with 1b genotype. As the most prevalent genotype in Polish blood donors is 1b, HCV infection in onco-haematological patients is most likely due to horizontal transmission, probably involving genotype 1a, and potential horizontal transmission of HCV is implied by the presence of 1a genotype of HCV in saliva and urine of selected patients. Spread of hospital HCV infection among children may be facilitated by micro-injury of the skin and mucosa. Early detection of HCV RNA is important in such immunosuppressed patients, as they are not able to produce anti-HCV antibodies. This may enable the introduction of prophylactic steps to prevent the spread of HCV infection by horizontal transmission.

Limited pattern of TCR delta chain gene rearrangement on the RNA level in multiple sclerosis.

Susceptibility to multiple sclerosis (MS) is most likely affected by a number of genes, including HLA and T-cell receptor (TCR) genes. T cells expressing gamma/delta receptors seem to contribute to autoagression in MS, as evidenced by their localization in the MS plaques in the brain. The aim of this study was to analyse the TCRdelta chain gene rearrangement at the RNA (cDNA) level and compare to the DNA pattern rearrangement. TCRdelta gene rearrangement was analysed in MS patients and healthy individuals with the use of primers specific for Vdelta1-6 and Jdelta1 genes (at the DNA level) and specific for Vdelta1-6 and Cdelta1 genes (at the cDNA level). The size of PCR products was analysed on agarose gel and by ALF-Express (Pharmacia). Additionally, the lymphocyte surface immunophenotype was studied with specific monoclonal antibodies. At the DNA level a restricted pattern of Vdelta3-Jdelta1 and Vdelta5-Jdelta1 was found only in MS patients. Contrary to DNA, mono-, oligoclonal RNA (cDNA) rearrangements were limited to Vdelta1-Cdelta1, Vdelta2-Cdelta1 and Vdelta3-Cdelta1 only in MS patients as well. Surface immunophenotype analysis revealed in MS a much higher frequency of activated gamma/delta T lymphocytes, i.e. expressing HLA-DR and CD25. An elevated level of CD56 positive cells in MS was recorded. Mono-oligoclonal pattern of TCRdelta gene rearrangement at the RNA level, along with increase in activated gamma/delta T cells, strongly argue for a significant role of gamma/delta T lymphocytes in the pathogenesis of MS.