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M Pappalettera

Publications and source records attributed to M Pappalettera.

30 records · Page 2Linked to original sources
PubMed1993

Genomic HLA-DR compatibility in long-term surviving recipients of cadaver kidney transplants.

The finding that HLA-DR compatibility assessed by DNA typing correlates with short-term graft outcome better than serology prompted us to study the degree of genomic HLA-DR compatibility on 55 patients with a graft functioning for more than 10 years (group A), compared with 82 patients with more recent transplants regardless of survival (group B). Because adequate blood donor samples were not available for group A long-term survivors, we used donor renal cells obtained by fine needle aspiration biopsy as a source of DNA. We found that in long-term survivors, the distribution of HLA-DR mismatches was significantly different from that observed in group B patients. In particular, whereas a similar proportion of patients with 1 mismatch was seen in both groups, 27.3% of group A patients vs. 6.1% of group B patients had no mismatch, and 23.6% of group A vs. 41.5% of group B patients received transplants with no HLA-DR compatibility (P = 0.001). We also investigated a possible correlation between number of incompatibilities and graft function. Well-matched patients received less steroid pulses than less well-matched recipients, and steroid-resistant rejection episodes were more common among less well-matched recipients. These results suggest a prognostic role of genomic HLA-DR compatibility on long-term success of cadaver kidney transplantation.

Adult↗
PubMed1992

Remissions and relapses in idiopathic membranous nephropathy.

To assess the significance of remissions and relapses in idiopathic nephrotic syndrome the outcome of 169 patients was reviewed of them III had either a complete or partial remission. The probability of obtaining a complete remission within 5 years was 44% for the whole group, being significantly higher (P = 0.015) for those patients who had been treated with steroids plus cytotoxic drugs. Of the 74 patients who had complete remission only two showed renal function deterioration over time. Relapse of non-nephrotic proteinuria occurred in 22 patients. Of these, 12 again entered complete remission spontaneously, which persisted in nine until the last observation. Relapse of nephrotic syndrome occurred in 42 of III patients. Six patients showed a moderate renal function deterioration. Of 27 untreated patients, 17 had again a partial or complete remission that persisted in 13 until the last observation. All the 15 patients submitted to treatment again entered remission, which persisted in nine of 11 patients given prednisolone and chlorambucil and only in one of four given steroids alone. In conclusion, (a) the development of complete remission is a good marker of an excellent renal outcome, (b) patients with relapse of non-nephrotic proteinuria usually carry a good prognosis, (c) about half of patients with relapse of nephrotic syndrome show a spontaneous remission, and (d) the chances of a stable remission may be increased by treatment with steroids and cytotoxic agents.

Adolescent↗
PubMedDate not supplied

A micro colorimetric assay using cryopreserved monocytes to evaluate antibody-mediated red cell-monocyte interaction.

BACKGROUND AND OBJECTIVE: A number of in vitro assays based on the interaction of red cells with monocytes have been used to determine the clinical significance of red cell antibodies. When used in our laboratory, one of these assays (the monocyte-macrophage phagocytosis assay-MMPA), was very time consuming and showed great variability. METHODS: We set up a monocyte phagocytosis colorimetric assay (MPCA), using standard microtiter plate wells coated at 37 degrees C for 1 hour with monocytes from healthy donors. After washing the wells to remove non-adherent monocytes, test red cells are added to the wells. Sensitized red cells bind to the monocytes, which are lysed after incubation to measure red cell phagocytosis. This is done by hemoglobin detection in the lysate through reaction with o-phenylenediamine and absorbance evaluation with a colorimeter. The results are expressed as the phagocytosis index (PI), which is calculated with the following formula: PI = [1-(A450 unsensitized red cells/A450 sensitized red cells)] x 100. In this study we determined: the source of MPCA variability; the precision of MPCA results; the correlation between MMPA and MPCA results; the MPCA reference values and the MPCA and MMPA execution times. RESULTS: MPCA variability depended largely on the monocyte source. The smallest variation coefficient of the results of replicate assays (19-21%) was found using pooled, cryopreserved monocytes. When performed with a pool of cryopreserved monocytes from 10 subjects, the SD of PI values obtained in replicate assays showed little variation (11-13) over the range of anti-D concentrations tested (from 18.75 to 300 ng/mL). A linear correlation coefficient r of 0.96 was obtained when MPCA and MMPA were performed in parallel, and the 95th centile of PI reference values determined with red cells of 40 non-transfused surgical patients free of irregular red cell antibodies was 7. MPCA execution time was 56% of that needed to perform MMPA. INTERPRETATION AND CONCLUSIONS: These studies show that MPCA is an easy and reproducible assay which allows objective and automated evaluation of red cell phagocytosis.

Colorimetry↗