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Evidence of hepatitis C virus passage across dialysis membrane

The passage of hepatitis C virus (HCV) across the dialysis membrane is a controversial issue. We performed a study applying extreme conditions of permeability to the dialysis membrane and avoiding the use of heparin and dialysis bath that might interfere with polymerase chain reaction (PCR) results. We obtained samples from the ultrafiltrate at the beginning of 18 hemodialysis sessions carried out in 6 HCV RNA-positive patients. HCV RNA was detected by PCR in 3 (16.7%) ultrafiltrate samples belonging to 1 of the patients. HCV genotype was the same as that found in positive ultrafiltrate samples and in the serum corresponding to this patient. The viral load of this patient was under the levels detectable by the assay employed. Therefore, contamination of the ultrafiltrate may constitute a potential risk for HCV transmission in hemodialysis units.

Hepatitis G Virus Infection in Hemodialysis Patients and Its Relationship with Hepatitis C Virus Infection

Our aim was to study the characteristics of hepatitis G virus (HGV) infection in hemodialysis (HD) patients. We evaluated 108 patients from two different units (A: 67 patients; B: 41 patients). HGV RNA and HCV RNA were detected by PCR. Nineteen patients (17.6%) were HGV RNA positive (20.9% in unit A and 12.2% in unit B (NS)). HCV RNA was positive in 19 patients (17.6%) (28.4% in unit A and 0 in unit B (p < 0.01)). Eight patients were HGV RNA and HCV RNA positive (group I), 11 HGV RNA positive (group II), 11 HCV RNA positive (group III), and 78 negative for both viruses (group IV). Time on HD was 51.3 +/- 37.0 months for group I, 36.0 +/- 27.9 months for group II, 63.5 +/- 40.2 months for group III, and 26.4 +/- 27.1 months for group IV (p < 0.01 for I and III). Seven patients (87.5%) from group I, 9 (81.8%) from group II, 10 (90.9%) from group III, and 44 (56.4%) from group IV had a history of transfusion (p < 0.03 for I, II and III). Two patients (25%) from group I, none from group II, 5 (45.4%) from group III, and 6 (7.7%) from group IV had chronic ALAT elevation (p < 0.01 for I and III). We conclude that HGV infection was frequent in our HD patients, related to transfusions and independent of HCV prevalence, and that HGV infection itself was not a cause of ALAT elevation suggesting chronic hepatitis.

Interferon DNA polymorphism in chronic leukemia.

The interferon (IFN) system (alpha, beta and gamma IFNs) is closely related to the first line of defenses against viral and tumoral diseases. Chronic leukemic and chronic lymphoproliferative patients respond in variable degrees to therapy with exogenous IFN. Remission after treatment with IFN-alpha in hairy cell leukemia (HCL) and in chronic myelogenous leukemia (CML) have been reported by other authors. In order to determine whether there are differences in IFN-alpha and beta genes between healthy and chronic leukemic individuals and among the different chronic leukemic patients, restriction fragment length polymorphism (RFLP) analyses was performed in a panel of patients with HCL, CML and chronic lymphocytic leukemia (CLL), and in a sample of healthy individuals. A significant difference in the allelic frequencies for the IFN-beta and Sst I enzyme in Chronic leukemias, mainly of myeloid origin, compared with the healthy individuals, was found.

Influence of hemodialysis procedure on HCV RNA detection in serum and peripheral blood mononuclear cells.

Aim. To assess whether hemodialysis procedure induces qualitative or quantitative changes in hepatitis C virus (HCV) RNA. Methods. We obtained blood samples in the 10 HCV RNA‐positive patients of our hemodialysis unit before (sample I) and 5 min after a dialysis session (sample II), and before the next dialysis session (sample III). HCV RNA was tested by PCR in serum and peripheral blood mononuclear cells (PBMC). Serum viral load was measured by branched‐DNA assay. Results. Serum HCV RNA was positive in samples I, II and III of the 10 patients. PBMC HCV RNA was detected in samples I, II and III of seven patients. Mean viral load was 1.43 ± 0.99 Meq genome/mL in sample I, 0.86 ± 0.40 Meq genome/mL in sample II and 1.27 ± 0.56 Meq genome/mL in sample III. Conclusions. HCV load was low in most HCV RNA‐positive patients. It had a downward trend during dialysis procedure but HCV RNA remained detectable in all serum samples and in most PBMC samples. Therefore, qualitative HCV RNA seems to be better than viral load to assess HCV infection in hemodialysis patients.

The role of transfusion-transmitted virus in patients undergoing hemodialysis.

Goals To study transfusion-transmitted virus (TTV) infection in 75 patients on hemodialysis and examine its relationship with age, sex, duration of dialysis, history of transfusion, and chronic elevation of alanine aminotransferase (ALT) levels. Study Serum TTV was analyzed by polymerase chain reaction (PCR), TTV genotypes by restriction fragment length polymorphism, and hepatitis C virus (HCV) RNA by PCR. Results Transfusion-transmitted virus was detected in 32 patients (42.7%). Transfusion-transmitted virus genotypes were as follows: G1 in 16 patients; G2, 3; G3, 1; G4, 2; G2-G5, 6; and unclassified, 4. Mean duration of dialysis was 37 ± 32 months for TTV-positive patients and 43 ± 37 months for TTV-negative patients (not significant). Twenty-seven (84%) TTV-positive patients and 27 (63%) TTV-negative patients had a history of transfusions (p = 0.04). Chronic ALT elevation was observed in 9 patients; 5 of them were TTV-positive (16%) and 4 were TTV-negative (9%) (not significant). Four (40%) HCV RNA–positive patients and 5 (8%) HCV RNA–negative patients had chronic ALT elevation (p = 0.003). Three TTV-positive patients with chronic ALT elevation were also infected with HCV. The two patients with isolated TTV infection did not have another clinical feature to explain their ALT elevation. Conclusions Transfusion-transmitted virus had a high prevalence in the patients on hemodialysis; genotype G1 accounts for half of the cases. Transfusion-transmitted virus infection depends on the transfusional antecedent but not on the duration of dialysis. Chronic ALT elevation is significantly associated with HCV infection but not TTV infection. However, TTV could be a causative agent of chronic ALT elevation in some patients.