Human Leukocyte Antigen Compatibility and De Novo Donor-Specific Antibodies in Long-term Renal Transplant Patients With Stable Graft Function.

PURPOSE: De novo donor-specific antibodies (DSA) are associated with antibody-mediated rejection leading to late renal transplant failure. The aim of this study was to evaluate whether HLA compatibility is associated with sensitization along with other risk factors. METHODS: Eighty-nine stable renal transplant recipients (47 men) were studied. Patients were classified into 2 groups according to HLA compatibility between donor and recipient, group A (1-4/8 matches) and group B (5-8/8 matches). Cold ischemia time (CIT) and delayed graft function (DGF) were recorded along with time with a functional graft. Anti-HLA antibodies were detected using a Luminex single-antigen bead assay and were further classified into DSA and non-DSA. RESULTS: HLA group A consisted of 49 (56%) transplant recipients while 38 (44%) were classified to group B, with functional grafts for 10.9 ± 6.7 and 14.8 ± 8.5 years, respectively (P = .019). Group A patients had more anti-HLA antibodies than group Β (P = .001) and this correlation was retained for DSA patients. De novo anti-HLA were detected in 40 patients; DSA were detected in 19 (21.8%). DSA (+) patients had recorded with functional renal grafts for 11 ± 5 years, compared to 14.4 ± 8.6 years (P = .048) for anti-HLA negative patients. Increased CIT and DGF were associated with anti-HLA antibodies detection but no with DSA. CONCLUSION: HLA compatibility is probably correlated with DSA in a context of a more general anti-HLA sensitization, and both have a negative effect on long-term renal graft outcome.

Prevalence and Impact of Reformed and De Novo Anti-HLA Donor-Specific Antibodies in Liver Transplantation.

INTRODUCTION: The prevalence and impact of pre-existing and de novo anti-HLA donor-specific antibodies (DSAs) after orthotopic liver transplantation (OLT) is still controversial. We investigated the prevalence of DSAs and their implication in the development of allograft dysfunction after OLT. PATIENTS AND METHODS: A total of 65 liver transplant patients were tested for anti-HLA antibodies, with single antigen bead technology, before, 1, 3, 6, and 12 months after transplantation, and thereafter annually, along with other risk factors. Sixteen out of 65 patients (24.6%) had circulating pre-existing anti-HLA antibodies, and 4 of them (25%) had DSAs. All patients positive for anti-HLA antibodies (100%) presented allograft dysfunction. Fourteen out of 65 patients (21.5%) had circulating de novo DSAs, and 12 out of 14 (85.7%) presented allograft dysfunction. The investigated risk factors for allograft dysfunction were: recipient and donor age, time on the waiting list, cold ischemia time, cytomegalovirus infection, immunosuppression regimen, de novo DSAs, Model for End-Stage Liver Disease, aspartate aminotransferase, alanine aminotransferase, gamma-glutamyl transpeptidase (GGT), direct bilirubin and total bilirubin peak post-transplant, and alkaline phosphatase. The multivariate analysis showed that de novo DSAs and time on the waiting list were independent risk factors for allograft dysfunction. CONCLUSION: Our results show that de novo DSAs are an independent risk factor for allograft dysfunction, along with time on the waiting list.

Hepatitis B reactivation in a renal transplant patient due to a surface antigen mutant strain: a case report.

INTRODUCTION: Reactivation of hepatitis B virus (HBV) is a complication of immunosuppressive treatment in patients with a history of HBV exposure. CASE PRESENTATION: Herein we have reported a case of reactivation after renal transplantation in a 52-year-old male chronic HBV carrier who was treated with hepatitis B immunoglobulin (HBIg) prophylaxis immediately after transplantation in addition to cyclosporine, mycophenolate mofetil and prednisolone for maintenance immunosuppression. After application of rituximab, the patient developed clinical hepatitis with a high load of HBV DNA. Sequence analysis of the surface (S) antigen corresponding to the amino acid residues 101-186 (including the a-determinant region) revealed a genotype D mutant strain, subtype ayw3 with a single amino acid substitution D144E within the S gene. CONCLUSION: This case suggested that immunosuppressive treatment enhanced with rituximab promoted the emergence of an HBV mutant within the determinant region of the S antigen, which escaped HBIg immunoprophylaxis causing HBV reactivation in a kidney transplant recipient.

Measles and mumps immunity in Northern Greece, 2004-2007.

A cross-sectional study was conducted in order to determine the prevalence of mumps and measles antibodies in a representative sample of the general population in Northern Greece between January 2004 and May 2007. Overall, 900 healthy individuals participated in the study. The great majority were found to be protected against measles. The total protection rate against mumps was significantly less (87% versus 72%, respectively; p<0.01). Compared to all other age groups, statistically significantly lower protection rates were found in children younger than 1.5 years (p<0.01). The lowest rates of all adult groups were found in the age group of 21 to 30 years (86% and 68% for measles and mumps, accordingly). In conclusion, protection rates against both measles and mumps seem to be lower than expected in certain age groups, such as infants and young adults.

Rubella immunity and vaccination coverage of the population of northern Greece in 2006.

This study was prompted by two rubella outbreaks that occurred in northern Greece in the last decade (1993 and 1999) and by periodic changes to the immunisation strategy. It was designed to determine the current status of rubella immunity and vaccination coverage in this region, eight years after the last outbreak in 1999 and seven years after the last epidemiological study in the area. Among the 685 subjects studied the seroprevalence was 83.7% and the total vaccination rate was 31.3%. In people born before the introduction in 1989 of the measles/mumps/rubella (MMR) vaccine into the national immunisation programme, higher rates of rubella seropositivity (88.1%) were observed compared to those born after 1989 (77.1%). The vaccination rates for these age groups were 14.8% and 58.1%, respectively. The reason for this difference is the lack of vaccination at the time these people were children, and it underlines the need for a vaccination strategy targeting older people as well. Among women of reproductive age (16-40 years), who represented 44.8% of the study population, 13.9% were susceptible to rubella and only 18.5% were vaccinated. These results indicate that there is a great need for a comprehensive policy designed to protect mostly young adults and women of childbearing age in order to prevent congenital rubella infections. This policy should also include competent surveillance systems for rubella and congenital rubella syndrome and an evaluation of existing immunisation programmes.