Adele Zanetti

Novel association of HLA-haplotypes with primary sclerosing cholangitis (PSC) in a southern European population

AIMS In patients with with primary sclerosing cholangitis we investigated the major histocompatibility complex (MHC) genes and mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. METHODS In 64 PSC patients and 183 normal controls of the same population (Northern Italy), allelic polymorphisms at the DNA level were investigated in MHC region genes: HLA-DRB1, HLA-DQB1 and HLA-B, tumour necrosis factor A (TNFA), and in CFTR gene, with polymerase chain reaction-based methodologies. RESULTS Frequencies of DRB1*01, DQA1*0101, DQB1*0102 (14 vs. 8%, p<0.05), DRB1*16, DQA1*0102, DQB1*0502 (8 vs. 3%, p<0.025) and DRB1*04, DQA1*03, DQB1*0301 (10 vs. 4%, p<0.005) haplotypes were more elevated in PSC patients. The frequency of patients positive for HLA DRB1*01, *1601 or *04 related haplotypes was significantly increased (32 vs. 14%, p<0.00025). DRB1*07, DQA1*0201, DQB1*02 haplotype frequency was significantly decreased (4 vs. 15%, p<0.001). After removing HLA-DRB1*01, *1601, *04 related haplotype sharing patients, HLA-DRB1*03, DQA1*0501, DQB1*02 haplotype frequency was significantly increased (32 vs. 14%, p<0.01). TNFA2 allele frequency was significantly increased in PSC patients (23 vs. 14%, p<0.025), as well as the TNFA2 homozygous genotype (9 vs. 0.5%, p=0.0013). No mutations were found on the CFTR gene and the allelic frequency of the 5T polymorphism in intron 8 was not increased. CONCLUSION These data suggest that the role of genes in the HLA region is relevant, but not necessarily disease-specific and it might be different in populations with divergent ancestries.

HLA and killer immunoglobulin-like receptor genes as outcome predictors of hepatitis C virus-related hepatocellular carcinoma.

Purpose: We evaluated the impact of the killer immunoglobulin-like receptors (KIR) of natural killer (NK) cells and of their HLA ligands over the clinical outcome of hepatitis C virus (HCV)–related hepatocellular carcinoma after curative treatment by either surgical resection or radiofrequency thermal ablation (RTA). Experimental Design: Sixty-one consecutive patients with HCV-related hepatocellular carcinoma underwent KIR genotyping and HLA typing. A phenotypic/functional characterization of NK cells was carried out in patients with different KIR/KIR-ligand genotype. Results: Activating KIR2DS5 was associated with significantly longer time to recurrence (TTR) and overall survival (OS; P < 0.03 each). Homozygous HLA-C1 (P < 0.02) and HLA-Bw4I80 (P < 0.05) were expressed by patients with significantly better OS, whereas HLA-C2 (P < 0.02) and HLA-Bw4T80 (P < 0.01) were associated with a worse OS. Multivariate analysis identified as parameters independently related to TTR the type of treatment (surgical resection vs. RTA; P < 0.03) and HLA-C1 (P < 0.03), whereas only KIR2DS5 was an independent predictor of longer OS (P < 0.05). Compound KIR2DL2-C1 and KIR3DS1-Bw4T80 genotypes were associated with better TTR (P < 0.03) and worse OS (P = 0.02), respectively. A prevalent cytotoxic (CD56dim) NK phenotype was detected in patients with both longer TTR and OS. Cytotoxic capacity measured by upregulation of CD107a was significantly higher in subjects with HLA-C1 alone or combined with KIR2DL2/KIR2DL3. Conclusions: These results support a central role of NK cells in the immune response against hepatocellular carcinoma, providing a strong rationale for therapeutic strategies enhancing NK response and for individualized posttreatment monitoring schemes. Clin Cancer Res; 19(19); 5465–73. ©2013 AACR.

Association of HLA-DRB1*0401 allele with chronic pancreatitis.

Introduction Chronic pancreatitis (CP) is characterized by irreversible morphologic and functional alterations of the pancreas, clinically presenting with upper abdominal pain as well as exocrine and endocrine insufficiencies. According to a more recent hypothesis, the pathogenesis may involve genetic and immunologic factors. Aim To investigate the major histocompatibility complex (MHC) genes as a genetic background of chronic pancreatitis. Methodology Allelic polymorphisms were investigated in the genes of the MHC region (HLA B, DRB, DQB) with PCR-based methodologies (PCR-SSP) in 56 patients with CP (44 males and 12 females) and 183 normal controls (78 males and 105 females) of the same ethnic group. All patients and controls gave their informed consent. Results Among HLA-DRB1 genes, DRB1*04 was significantly higher in CP patients than in controls (26.78% versus 8.1%;pc < 0.003; OR = 4.1; CI = 1.85–9.06). DRB1*04 allele specificities in the DRB1*04-positive patients demonstrated significantly higher frequencies of DRB1*0401 allele (14.3% versus 1.1%;p = 0.00017; OR = 15.08; CI = 3.1–73.36). Neither HLA-B nor HLA-DQB1 associations with the disease were found. Conclusions This study supports a role of HLA-DRB1*0401 as a susceptibility factor for patients with CP. HLA DRB1*0401 contains the 70QKRAA74 amino acid sequence, which is also expressed by several human pathogens, including Epstein-Barr virus. T cells may be triggered in the pancreatic tissue upon exposure to foreign peptides similar enough to cross-react and to break immunologic tolerance.