The impact of immunogenetics and clinical factors on the outcome of unrelated cord blood transplantation: the Milano Cord Blood Bank data.

In this article we examined the role of HLA incompatibility, of KIR C1 and C2 ligands and of other clinical factors on 99 cord blood transplants performed using single units from Milano Cord Blood Bank (MICB). We analyzed the occurrence of rejection, overall patient survival (OS) and occurrence of acute GvHD >or= 2 grade (severe aGvHD). No correlation was found between the end points and the number of HLA-A,-B, -DRB1 and -DQB1 mismatches. Only HLA-C disparities are associated with the occurrence of rejection (P=0.03). Our results showed that the presence of the C1 ligand in the donor decreased the occurrence of aGvHD (grade >or= 2) in the recipient while recipients of donors expressing the C2 KIR ligand experienced more frequently aGvHD (P=0.03). The HLA-C1 ligand, therefore, proved to have a protective effect towards severe aGvHD. The probability of rejection increased in KIR epitope-mismatched recipient/donor pairs (P=0.01). Finally the stage of disease at transplantation and cell dose were important for patient survival (P=0.003, P=0.048 respectively).

Detection of viral DNA in kidney graft preservation and washing solutions is predictive of posttransplant infections in pediatric recipients.

BACKGROUND: In pediatric kidney transplant recipients, viral infections occur soon after transplant and may be transmitted from the graft. METHODS: This study of 75 pediatric kidney transplants investigated whether genome sequences of parvovirus B19, Epstein-Barr virus (EBV), human cytomegalovirus (HCMV), and BK polyomavirus (BKV) could be detected in kidney graft samples (graft biopsy samples and preservation and washing solutions) collected before implantation and whether their presence was a risk factor for infections in the recipient. RESULTS: B19 DNA was detected in approximately 30% of graft biopsy samples, preservation solutions, and washing solutions; EBV DNA was detected in approximately 20% of preservation and washing solutions but rarely in biopsy samples; and HCMV DNA and BKV DNA were rarely detected in graft biopsy samples. Seronegative recipients of B19 DNA-positive and EBV DNA-positive grafts had a significantly higher risk of infection during the early posttransplant period than did recipients of negative grafts. In particular, none of the B19-seronegative recipients of B19 DNA-negative grafts experienced infection soon after transplant, whereas most recipients of B19 DNA-positive grafts experienced infection within the first month after transplant. CONCLUSIONS: Molecular testing of donor grafts for viruses that infect circulating and resident cells in the graft-such as B19 in the kidney-could be useful (in association with donor/recipient serostatus) for identifying recipients at high risk for posttransplant infections.

Killer cell immunoglobulin-like receptor genotype and killer cell immunoglobulin-like receptor-human leukocyte antigen C ligand compatibility affect the severity of hepatitis C virus recurrence after liver transplantation.

In 20% to 30% of infected individuals, hepatitis C virus (HCV) can cause cirrhosis and hepatocellular carcinoma, for which liver transplantation is the best treatment available. HCV re-infection is universal, and hepatitis disease recurrence occurs in most cases with a 30% probability of progression to graft cirrhosis at 5 years post-transplant. The immunological response to HCV involves natural killer (NK) cells and killer cell immunoglobulin-like receptors (KIRs), which specifically recognize human leukocyte antigen (HLA) class I antigens present on target cells. The effector functions of NK cells are influenced by inhibitory KIR interaction with self-HLA class I ligands, with HLA-C being the most predominant. This study examines the roles of KIR genotypes and their HLA ligands in both HCV disease recurrence and its progression. A total of 151 patients were included in the cohort, and their clinical details were recorded. Liver biopsies were used to define the absence/presence of recurrent hepatitis, the degree of fibrosis, and the progression to cirrhosis over a 10-year period. Mismatching of KIR-HLA-C ligands between donor-recipient pairs was associated with the recurrence of hepatitis (P = 0.008). The presence of KIR2DL3 in the recipient correlated with progression to liver fibrosis (P = 0.04). The mismatching of HLA-KIR ligands favored the progression of the recurrent hepatitis to fibrosis only in the presence of KIR2DL3 (P = 0.04). These preliminary results indicate that the KIR genotype and KIR-HLA-C ligand compatibility play roles in the recurrence and progression of hepatitis C disease in liver transplant recipients.

Peculiar HLA polymorphisms in Italian patients with primary biliary cirrhosis.

BACKGROUND/AIMS: Primary biliary cirrhosis (PBC) is an autoimmune cholestatic liver disease of unknown etiology with a highly variable progression rate and prevalence among different geographical areas. Data concerning human leukocyte antigen (HLA) polymorphisms in PBC come from a limited number of geographical areas, from which the association with the HLA-DRB1*08 allele has been consistently reported. METHODS: To investigate whether HLA polymorphisms contribute toward disease susceptibility, we compared 186 well-defined Italian PBC patients with 558 healthy subjects matched by age, gender and geographical area (Northern, Central and Southern Italy). Patients and controls were HLA typed at low resolution by PCR-sequence specific oligonucleotides for the loci A and B; HLA-DRB1 alleles were typed by reverse line blot assay of PCR-amplified DNA. RESULTS: HLA-DRB1*11 was associated with a markedly reduced risk of developing PBC (OR: 0.3; 95% CI: 0.2-0.5). No association was found with HLA-DRB1*08. The B*15 (2.5; 1.3-4.6), B*41 (12.0; 2.7-72.1), B*55 (2.9; 1.1-7.5) and B*58 alleles (6.8; 1.1-46.3) were more frequent in PBC. The frequency of HLA polymorphisms was similar in PBC patients with progressive or non-progressive disease, and in those with or without anti-mitochondrial antibodies. CONCLUSIONS: Our data on a large series of Italian patients suggest that PBC may have a peculiar genetic background in the Mediterranean area.