Rosana Groppa

Effect of the embolization of completely unpurified islets on portal vein pressure and hepatic biochemistry in clinical practice.

Here we report on the impact of completely unpurified islet transplantation on the portal vein pressure (PVP) and the hepatic biochemistry in the peritransplant period and on follow-up. Type I diabetic patients underwent simultaneous kidney and islet transplantation. Islets were not purified from the acinar tissue to prevent loss of endocrine mass. Each patient received a mean 521,846 ± 201,539.4 islet equivalents (7812.1 islet equivalents/kg/recipient). Immunosuppression and peritransplant medication were given according to the Giessen protocol. The islets were injected into the left hepatic lobe through the umbilical vein. PVP was recorded at time 0 and every 5 min throughout cell infusion. Liver function was assessed daily for the first 10 days, and on follow-up. Basal, peak, and final PVP were 12 ± 3.8, 25.1 ± 7.9, and 19.5 ± 6.2 mmHg, respectively (basal vs. final, p < 0.05). Bilirubin, alkaline phosphatase, prothrombin time, and APTT stayed within normal range. Peak aspartate aminotransferase (AST), alanine aminotransferase (ALT), and serum amylase were 109.4 ± 61.2 IU/L (basal vs. peak, not significant), 79.5 ± 56.9 IU/L (basal vs. peak, not significant), and 887.5 ± 153.6 IU/L (basal vs. peak, p = 0.02), respectively. In all cases AST, ALT, and amylase normalized within 6 days posttransplant and remained so on follow-up (longest control, 33 months posttransplant). Although the intrahepatic infusion of unpurified pancreatic islets affects both the portal vein pressure and the hepatic biochemical profile, this effect is transient and does not compromise the safety of the procedure.

Pharmacogenetics of Immunosuppressant Polymorphism of CYP3A5 in Renal Transplant Recipients

The tacrolimus is metabolized primarily by CYP3A5, a member of the single nucleotide polymorphism family. It shows cytochrome P450 (SNP) in intron 3, which consists of a change of base, G for A, producing a stop codon. The result is a nonfunctional protein (allele *3). Allele *1 is the wild type. The patients that show the allelic variant *3 in homozygosis (G/G) are slow metabolizers of the immunosuppressant, increasing its concentration in blood. In contrast, heterozygote A/G alleles *1/*3 are intermediate metabolizers, whereas those of allele *1 in homozygosis (A/A) are normal metabolizers. The aim of this study was to determine CYP 3A5 polymorphism among adult renal transplant recipients and the general Argentinean population. We analyzed 21 recipients and 36 healthy controls. All subjects gave written informed consent approved by the local committee. To determine the polymorphism, we extracted DNA from peripheral blood and used polymerase chain reaction (PCR) to amplify intron 3 of the CYP 3A5. The presence of variant was confirmed by direct sequencing. Among the controls the CYP3A5 genotype *3/*3 (G/G) was detected in 32 individuals, 4 showed *1/*3 (A/G), and none had *1/*1 (A/A); among the recipients, the results were as follows: 18, 2, and 1, respectively. The frequencies of polymorphism in both groups were similar, although they differed from those published for other populations. These results are the basis for the development of a pharmacogenomic program applied to organ transplantation. The genetic polymorphisms can determine responses to drugs. The molecular diagnosis must be transferred to clinical practice so as to guide selection of medicine and drug doses to be optimal for each individual.

Initial experience with clinical islet transplantation in Argentina.

WHOLE pancreas transplantation may be the best therapeutic option for type I diabetic patients in advanced stages of their disease. However, those patients who are not eligible for whole pancreas transplantation may still benefit from pancreatic cell transplantation, which in spite of its lower rate of insulin independence, involves a minor surgical procedure and a lower posttransplant risk. We herein report our initial experience on pancreatic islet transplantation at a kidney and pancreas transplantation program based in Argentina since 1995.