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Hyperhomocysteinemia (Hcy) is an independent factor of cardiovascular disease, which is the main cause of morbidity and mortality both in uremic and kidney transplant patients. The aim of the study was to determine Hcy, plasminogen activator inhibitor (PAI-1) and lipoprotein (a) (Lp(a)) serum levels in 70 patients with a well functioning renal transplant. We also verified whether these levels were modified by a multivitamin therapy. The genetic polymorphism of the methylenetetrahydrofolate reductase (MTHFR) enzyme which plays a main role in Hcy metabolism, was studied as well. We found Hcy, PAI-1 and Lp(a) levels significantly elevated with respect to healthy control subjects. The thermolabile form of the MTHFR enzyme was linked to higher Hcy levels. After a short time on therapy with B6, B12 and folic acid vitamins, Hcy and PAI-1 decreased to normal levels. The authors conclude that high Hcy levels could be a relevant covariate for cardiovascular disease in transplant patients and they suggest that vitamin supplementation be recommended as a part of therapy.

Hyperhomocysteinemia is a well established risk factor for atherothrombotic disease, and the request for homocysteine determinations and the number of laboratories that need to perform this assay to assess individual risk profile is increasing. Different methods to evaluate homocysteine plasma levels are at present available. In the present study three methods, an in-house high-pressure liquid chromatographic (HPLC) method (considered as reference method) and two commercial immunoassays, an enzyme-linked immunoassay (EIA) and an automated fluorescence polarization immunoassay (FPIA), were used to measure homocysteine plasma levels in 100 samples. The median of homocysteine plasma levels obtained by HPLC was 9.0 micromol/L (range 4.2-23.0); the median of values obtained by EIA and FPIA were 10.6 micromol/L (range 3.3-21.5) and 9.6 micromol/L (4.8-20.2), respectively. The FPIA method showed the lowest within-run and between-run coefficients of variation (3.6% and 4.1%, respectively). There was a significant correlation between EIA and HPLC (r=0.81; p0.0001), and between FPIA and HPLC (r=0.85; p0.0001). The Bland-Altman analysis showed that FPIA agreed best with HPLC; EIA displayed a relatively wide scatter of difference data points. The present results indicate that the technological characteristics of the FPIA assay make this method suitable for the determination of Hcy in clinical laboratories.

In addition to its well-understood anticoagulant activity, heparin is known to modulate a variety of biological functions including immunologic responses. In order to investigate whether heparin influences the humoral immunity by interacting with cellular elements and affecting gene expression in blood circulating cells. we studied the effect of heparin on IL-1beta, IL-6 and TNFalpha mRNAs in human lipopolysaccharide-(LPS)- or interferon-gamma(IFN-gamma)-stimulated mononuclear cells. The study of mRNA was carried out by an initial PCR screening followed by a Northern blot quantitative analysis. Heparin (0.5 U/ml) turned out to inhibit all three cytokine gene expressions. The mRNA decrease was 37 +/- 6% for IL-1beta, 53 +/- 3% for IL-6 and 47 +/- 4% for TNFalpha with LPS stimulus. No differences could be observed in the inhibitory effect of heparin on IFNgamma-stimulated cells. This effect of heparin was confirmed in a subset of experiments performed on purified monocytes. These results suggest an important immunosuppressive effect of heparin on cell-mediated immune responses.

A difference in the prevalence of venous thromboembolism (TE) in major human groups has been described and an uneven distribution of FV Leiden mutation over the world has recently been reported. We investigated FV Leiden mutation in 584 apparently healthy subjects mostly from populations different from those previously investigated: 170 Europeans (Spanish, Italians), 101 sub-saharan Africans (Fon, Bariba, Berba, Dendi), 115 Asians (Indonesians, Chinese, Tharus), 57 Amerindians (Cayapa), 84 Afroamericans (Rio Cayapa, Viche), and 57 Ethiopians (Amhara, Oromo). The mutation was detected in only 1/115 Asian (Tharu) and in 5/170 Europeans (4 Italians, 1 Spanish). These data confirm that in non-Europeans the prevalence of FV mutation is at least 7 times lower than in Europeans and provide indirect evidence of a low prevalence not only of the FV Leiden gene but also of other genes leading to more severe thrombophilia. Finally, findings from the literature together with those pertaining to this study clearly show a marked heterogeneity among Europeans.