Human leukocyte antigen and adult living-donor liver transplantation outcomes: an analysis of the organ procurement and transplantation network database.

Human leukocyte antigen (HLA) compatibility has no clinically significant impact in cadaveric liver transplantation. Less is known regarding living-donor liver transplantation (LDLT). Our prior analysis of the Organ Procurement and Transplantation Network (OPTN) database suggested a higher graft failure rate in patients who underwent LDLT from donors with close HLA match. We further investigated the effect of HLA-A, -B, and -DR matching on 5-yr graft survival in adult LDLT by analyzing OPTN data regarding adult LDLT performed between 1998 and 2005. We evaluated associations between 5-yr graft survival and total, locus-specific, and haplotype match levels. Separate analyses were conducted for recipients with autoimmune (fulminant autoimmune hepatitis, cirrhosis secondary to autoimmune hepatitis, primary biliary cirrhosis, primary sclerosing cholangitis) or nonautoimmune liver disease. Multivariable Cox proportional hazard models were used to evaluate interactions and adjust for potential confounders. Among 631 patients with available donor/recipient HLA data, the degree of HLA match had no significant effect on 5-yr graft survival, even when analyzed separately in recipients with autoimmune vs. nonautoimmune liver disease. To be able to include all 1,838 adult LDLTs, we considered a first-degree related donor as substitute for a close HLA match. We found no difference in graft survival in related vs. unrelated pairs. In conclusion, our results show no detrimental impact of close HLA matching on graft survival in adult LDLT, including in recipients with underlying autoimmune liver disease.     

Renal transplantation from elderly living donors

A worldwide shortage of cadaveric donors has led to the increased utilization of elderly living donors, with controversial results. In an attempt to assess the effect of donor age on graft survival and subsequent renal function, we analyzed our clinical results in 276 consecutive recipients of living related renal transplants spanning both the cyclosporine and the azathioprine eras, of whom a total of 44 recipients received kidneys from donors over 55 years old. All recipients were otherwise similar in age, race, haplotype mismatch, number of retransplants, and number of pretransplant transfusions, apart from an increased number of diabetics among the CsA-treated recipients of elderly kidneys (38% vs. 14%). The cumulative patient and graft survival rates at 1 and 5 years were independent of donor age whether CsA or AZA was utilized. Nor was the incidence of rejection or infection significantly different in the older donor group when compared with the younger cohort. Short-term and intermediate-term renal function, as assessed by serum creatinine, was however poorer but stable in the older donor group when compared with the younger one. The mean serum creatinine levels at 1 year in the CsA- and AZA-treated recipients of kidneys from older donors were 2.4 and 2.0 mg/dl, respectively, compared with 1.6 and 1.4 mg/dl, respectively, when the donor age was less than 55 years (P less than 0.001). Since renal function at the end of the first posttransplant year is considered a determinant of long-term graft survival, this is a cause for concern, but in view of the universal shortage of organs and the negligible morbidity to donors, renal transplantation from elderly living donors remains an acceptable practice.     

Non-isotopic hybridization assays for bacterial DNA samples

The background problem associated with the use of streptavidin in detecting biotin-labelled probes hybridized to DNA in crude bacterial extracts has been investigated. We have found that streptavidin binds specifically to a limited number of polypeptides which are difficult to remove by rapid extraction processes. Altering the hybridization and detection protocols results in a marked but not complete reduction of non-specific background in streptavidin-biotin assays. Complete elimination of non-specific background was achieved only when streptavidin was replaced with antibodies for the detection of biotinylated or sulphone-modified probes. The antibody-sulphone and streptavidin-biotin dot blot assays described here require 4.5-5 hours to perform and can detect DNA sequences in samples extracted from 2 x 10(7) cells or fewer.     

Alpha 1-antitrypsin deficiency and anti-proteinase 3 antibodies in anti-neutrophil cytoplasmic antibody (ANCA)-associated systemic vasculitis.

alpha 1-antitrypsin (alpha 1-AT) is a naturally occurring inhibitor of proteinase 3 (PR3) and elastase, two of the target antigens of anti-neutrophil cytoplasmic antibodies (ANCA). An increased incidence of alpha 1-AT phenotypes associated with dysfunctional alpha 1-AT or low serum levels has been reported in patients with anti-PR3 antibodies. We have studied the relationship between ANCA, and phenotypes and serum levels of alpha 1-AT. Phenotypes usually associated with a moderate or severe reduction in alpha 1-AT serum levels or in dysfunctional activity were found more often in individuals with anti-PR3 antibodies than in the general population: four of the 31 patients (13%) with anti-PR3 antibodies had phenotypes MZ (n = 2), S (n = 1) or Z (n = 1) (P < 0.05). However, the corresponding alpha 1-AT serum levels were normal (n = 3) or elevated (n = 1). None of the 31 sera with anti-PR3 antibodies had low levels of alpha 1-AT. No abnormal alpha 1-AT phenotype was demonstrated in seven patients with anti-elastase antibodies, despite a low level of alpha 1-AT in one serum. Anti-myeloperoxidase antibodies are common in patients with ANCA, but no abnormal phenotype or low serum alpha 1-AT level was demonstrated in any of 29 sera containing these antibodies. Finally anti-glomerular basement membrane (GBM) antibodies occur occasionally in patients with ANCA-associated diseases, but again none of 10 sera had an abnormal alpha 1-AT phenotype or low serum level. ANCA were not demonstrated by indirect immunofluorescence in any serum from 73 patients with abnormal alpha 1-AT phenotypes. These results confirm that patients with anti-PR3 antibodies often have alpha 1-AT phenotypes that are usually associated with low serum levels of alpha 1-AT or with dysfunctional protein. Nevertheless, the incidence of anti-PR3 antibodies in patients with abnormal alpha 1-AT phenotypes is very low. This probably reflects the rarity of Wegener's granulomatosis, the major disease associated with anti-PR3 antibodies, and the relative frequency of abnormal alpha 1-AT phenotypes. The mechanism for the development of anti-PR3 antibodies in patients with abnormal alpha 1-AT phenotypes is not clear, but may relate to the increased propensity of unbound and uninhibited PR3 to stimulate autoantibody production.     

An examination of polymorphic genes and folate metabolism in mothers affected by a spina bifida pregnancy

The effect of four polymorphic genes of folate-dependent methionine biosynthesis have been investigated in mothers affected by a neural tube defect pregnancy (NTD) and matched controls. The influence of the various genotypes on total red cell 5-methyl-H(4)folate,5,10-methenyl-H(4)folate, and 5-formyl-H(4)folate is reported, as is the effect on homocysteine and radioassay folate in both serum and red cells. All of the single nucleotide polymorphisms studied would seem to contribute to the cellular folate profile in some way. From the data presented, and from the work of others, it is likely that C677T 5,10-methylenetetrahydrofolate reductase is the most important of these polymorphisms. Control mother folate profiles seem reasonably predictive of any given methionine cycle mutation, but profiles in NTD mothers do not. On this basis, it seems likely that some other, as yet unidentified folate lesion is causal for NTD. In NTD-C677T 5,10-methylenetetrahydrofolate reductase in particular, indexes of folate depletion such as high-performance liquid chromatography (HPLC) folate level, oligo-gamma-glutamyl chain length, homocysteine, and radioassay folate values all seem to deteriorate with increased mutant allele carriage. This indicates that this folate polymorphism may provide a critical threshold effect that helps to promote NTD occurrence in the presence of another, as yet unidentified folate-related factor. In more general terms, on a by genotype basis, all 11 genotypes studied give NTD mothers a higher homocysteine compared to controls. Furthermore, a trend that is less universal indicates that NTD mothers have higher 5,10-methenyl-H(4)folate and 5-methyl-H(4)folate levels and lower 5-formyl-H(4)folate and H(4)PteGlu(1) levels than do controls. One of the most consistent, and possibly specific, differences between participant groups is a statistically significant elevation of 5,10-methenyl-H(4)folate in NTD mothers (affects three genotypes). Possible interpretations of this finding are discussed.     

Studies in gastric carcinogenesis. II. Absence of elevated concentrations of N-nitroso compounds in the gastric juice of Greek hypochlorhydric individuals

The concentrations of nitrate, nitrite, N-nitrate compoundsand bacteria were measured in 96 samples of fasting gastricjuice, pH 0.90–8.50, obtained from 56 individuals justbefore or at various times (8 days –1 year) after gastricoperation. The mean pH of the post-operative samples [4.66 ±0.39 (SEM)] was significantly higher than that of the pre-operativeones [3.29 ± 0.33 (SEM]. A positive correlation withpH was observed for the concentrations of total and nitrate-reducingbacteria (median values 5.0 x 10⁵ organisms/ml and 9.2 x 10⁴organisms/ml, respectively, for samples with pH6.5, and 1.2x 10³ organisms/ml and 0 organisms/ml, respectively, for sampleswith pH 2.5) and nitrite [mean values 22.5 ± 3.1 (SEM)µM and 3.20 ± 0.5 (SEM) uM for samples with pH6.5 and pH 2.5, respectively]. No correlation with pH was seenfor the concentrations of nitrate [mean value 0.48 ±0.06 (SEM) mM] or N-nitroso compounds [mean value 0.30 ±0.06 (SEM) µM]. The concentrations of bacteria and nitrite,although increased in hypochlorhydric individuals, were lowerthan those reported for corresponding individuals in other,primarily British, studies. It is suggested that the relativelylow concentrations of nitrite observed in our hypochlorohydricpopulation may account for the absence of elevated concentrationsof N-nitroso compounds and that the latter phenomenon may berelated to the relatively low frequency of gastric cancer inGreece.