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Biomedical subjects

G Martina

Publications and source records attributed to G Martina.

84 records · Page 5Linked to original sources
PubMedDate not supplied

Extrahepatic immunological manifestations of hepatitis C virus in dialysis patients.

BACKGROUND: Hepatitis C virus (HCV) infection may be associated with various extrahepatic immunological disorders. Uremic patients on chronic regular dialytic treatment (RDT) frequently develop immunological abnormalities. The aim of this study was to evaluate the probability that HCV infection creates an increased risk for extrahepatic immunological abnormalities in chronic RDT patients. SUBJECTS AND METHODS: In a series of one hundred sixteen chronic RDT patients, HCV status was determined by anti-HCV antibodies, polymerase chain reaction (PCR) RNA and viral genotyping. After excluding four anti-HCV negative/PCRRNA positive patients, a comparison was made between 51 anti-HCV negative/PCR-RNA negative and 61 anti-HCV positive patients, this latter group including seventeen PCR-RNA negative, fifteen genotype 1, thirteen genotype 2, three genotype 3, four genotype 4, four undeterminable genotype and five mixed genotypes. The following investigations were performed: cryoglobulinemia (presence, titer and, when possible, identification), monoclonal gammopathy, antineutrophil cytoplasm antibodies, antidouble stranded DNA antibodies, circulating immunocomplexes and immunoglobulin levels. RESULTS: Cryoglobulinemia was found in 77% of anti-HCV positive versus 29% of anti-HCV negative patients, and cryocrit > 1% in 50% versus 9.8% respectively, p=<0.01. Also cryoglobulin concentration was higher (logarithmic transformation: 4.38 +/- 0.94 vs 3.11 +/- 1.06, p =< 0.001) in anti-HCV positive versus negative patients. Multivariate logistic regression analysis showed a significantly increased odds ratio (12.0, confidence interval 3.0 to 48.3) for having high levels of cryoglobulins (cryocrit >1%) after adjusting for age and dialytic age. The prevalence of this abnormality did not differ significantly among patients infected with different genotypes, but a tendency towards a lower frequency was observed in the anti-HCV positive/PCR negative subgroup. Cryoglobulins were identified as type I (2 anti-HCV positive case), type II (2 anti-HCV positive and 1 anti-HCV negative case) and type 3 (1 anti-HCV negative case). The frequency of monoclonal gammopathy was not significantly different between anti-HCV positive and anti-HCV negative patients (6.5% versus 2%) as well as that of the other parameters evaluated except for IgG concentration which was higher in the anti-HCV positive group (1,685 +/-605 versus 1349 +/- 352 mg/dl, p 0.006). Five events, potentially linked to HCV infection, occurred in our anti-HCV positive patients: 2 cases of porphyria cutanea, 1 case of unexplained peripheral neuropathy, 1 cutaneous leukocytoclastic vasculitis, 1 death for non-Hodgkin's lymphoma. In one anti-HCV positive patient treated with interferon-alpha, the presence of cryoglobulins, monoclonal gammopathy and high IgG levels strictly paralleled that of viremia, disappearing during the recovery phase under treatment and reappearing shortly after stopping treatment. CONCLUSIONS: HCV infection provides a significantly increased risk for developing extrahepatic immunological abnormalities also in chronic RDT patients. It is possible that the clinical relevance of this event might be scant because of the low level of these abnormalities, but an awareness of its possibility should to be taken into account.

Adult↗
PubMedDate not supplied

[Effects of erythropoietin on the cardiovascular system and the intradialytic hemodynamic behavior].

The aim of the study was to evaluate, before and after hemodialysis (HD), the effects of partial correction of anemia with erythropoietin on: cardiac index (CI), stroke index (SI), heart rate (HR), ventricular ejection index (EVI), mean arterial pressure (PAM) and systemic vascular resistance index (SVRI). Cardiac parameters were gathered by means of transthoracic bioimpedance (BoMed). Twelve patients (6 M, 6 F) aged 50.6 +/- 5 years, on HD for 92.8 +/- 15.9 months, were studied twice (basal, end of follow-up). Before rHuEPO therapy, 6 patients had a "pathologic" cardiac response to HD (defined as an increase of CI despite the reduction of pre-load). After rHuEPO, 5 out of 6 patients with a "pathologic" response reverted to a "normal" response, and 1 hypertensive patient from a "normal" to a "pathologic" response. The EVI, CI and SI of patients with "pathological" response significantly improved after rHuEPO as compared with pre rHuEPO values (EVI 1.36 +/- 0.14 vs 1.07 +/- 0.08, p = 0.023; CI 3.18 +/- 0.24 vs 1.78 +/- 0.27, p less than 0.01; SI 43 +/- 3.7 vs 24 +/- 3.8, p less than 0.01). In conclusion, partial correction of anemia with rHuEPO induces an improvement of myocardial performance, without significant hemodynamic adverse effects. Our results suggest also that anemia could play a significant role in the pathogenesis of myocardial disfunction in HD patients.

Adult↗
PubMedDate not supplied

[Biofiltration without buffering substances in the dialysate].

A new hemodiafiltration technique, acetate free biofiltration (AFB), has been recently introduced in the treatment of chronic uremia. It is performed with a buffer free dialysate and a simultaneous infusion in post-dilution mode of a sodium bicarbonate solution (concentration 145-166 mEq/l; infusion rate 1.2-2 l/h). A polyacrylonitrile hollow fiber AN69 HF 1.2 sqm dialyzer is employed. In acute studies pCO2 remains stable throughout the treatment, as well as pCO2. We have found a significant inverse correlation between delta[HCO3-] pre and post treatment and basal [HCO3-] (r = -0.88; p less than 0.001), with an excellent correction of uremic acidosis, avoiding post dialytic alkalosis. Our long term experience on 6 patients followed up to 31 months, allows us to consider AFB as a feasible and safe treatment, offering a good correction of uremic acidosis and an excellent hemodynamic tolerance. We propose AFB as a competitive technique with respect to bicarbonate hemodialysis, hemodiafiltration and standard biofiltration.

Acidosis↗
PubMedDate not supplied

[Specificity, sensitivity and reproducibility of 2 methods of determining serum immunocomplexes (solid-phase C1q and polyethylene glycol precipitation)].

In the last years a few tests for the detection of circulating immune complexes (CIC) have been published. Nevertheless the data concerning their sensitivity and reproductibility are often partial. The Authors have here analysed, following this point of view, two methods for the detection of CIC, based on different mechanisms and therefore able to identify different kinds of CIC; the tests are: the PEG precipitation test and the C1q solid phase method. The reproductibility of the two methods is good, even when the samples have been many times thawn or kept at 20 degrees C for a few weeks; C1q test sensibility appears distinctly better than PEG test sensibility. By the two methods, but particularly with the PEG, it is possible to identify fluctuation of the IC levels during the day. The contemporaneous use of these two techniques can give results really useful to clinically monitorize some immune complexes diseases, such as many human glomerulonephrites.

Antigen-Antibody Complex↗