Maria Edvige Fasano

HLA‐DQB1 alleles in Italian patients with mucous membrane pemphigoid predominantly affecting the oral cavity

Background Mucous membrane pemphigoid (MMP) used to be considered as a single entity but it is now evident that a range of variants exists. Among them, pure ocular cicatricial pemphigoid (OCP) and pure oral pemphigoid (OP) appear to be very different subsets. Previous immunogenetics studies have found increased occurrence of the DQB1*0301 allele mainly in patients with OCP whereas in patients with OP the data are more open to doubt.

Cytokines and chronic rejection: a study in kidney transplant long-term survivors.

Background. In part, the long-term survival of kidney transplants depends on the efforts to perform grafts with good human leukocyte antigen (HLA) compatibility, but there are other mechanisms that must induce some sort of tolerance and impair the anti-graft immune reaction. Because cytokines are one of the main components of immune response, we evaluated single nucleotide polymorphisms (SNPs) of several cytokine genes that may influence the production of a given cytokine and therefore the features of immune reactions. Methods. A total of 416 first cadaveric kidney transplants were monitored for HLA matching. After 10 years, the graft was still functional in 171 of 416 patients; 102 of 171 patients were also typed for cytokine polymorphisms. Results. The mismatch distributions in patients who underwent transplantation were not statistically different from the entire group of patients who underwent transplantation during the same time period. Moreover, it seems that almost all of the HLA class I incompatible long-term survivors are homozygous for GG at the −1082 interleukin (IL)-10 or CC at the −33IL4. Conclusions. We observed that a match for class I and class II HLA antigens apparently does not favor the long-term survival of transplanted kidneys. In fact, matched grafts are lost before 10 years in the same proportion as the mismatched grafts. We also demonstrated (1) that patients who are homozygous for GG at the SNP −1082IL10 (high IL-10 producers) and HLA class I mismatched (but matched for class II) are protected from chronic rejection, and (2) that patients who are homozygous for CC at the SNP −33IL4 (low IL-4 producers) and HLA class I mismatched (regardless of matching for class II) are protected from chronic rejection.

Angiotensin I-converting enzyme genotype significantly affects progression of IgA glomerulonephritis in an italian population.

To evaluate the role of angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism in the progression of immunoglobulin A glomerulonephritis (IgA-GN), genotype distribution in 81 biopsy-proven cases of IgA-GN was studied. A logistic regression model showed that the risk for homozygous DD was not significantly elevated in patients with IgA-GN compared with healthy subjects (odds ratio = 1.16; confidence interval [CI], 0.4 to 3.3). However, the 5-year (78% v 90%) and 10-year (52% v 82%) renal survival rates for 47 patients with serum creatine (Cr) levels of 1.5 mg/dL or less at biopsy was significantly less in DD patients (n = 18; chi2 = 5.41; P = 0.02). The hazard ratio (HR) for DD (multivariate analysis from Cox proportional model after adjustment for known factors of progression, such as hypertension [HPT] and proteinuria [PTO]) was 3.07 (CI, 1.1 to 9.4). The HR for heavy PTO was 6.1 (CI, 1.9 to 19). The association of DD genotype with progression was even more striking when patients with other risk factors (heavy proteinuria) were excluded, as shown by DD-related risk in the absence (HR = 3.6; CI, 1.1 to 12) and presence (HR = 2; CI, 0.4 to 10) of PTO. The risk ratio was further increased by the coexistence of DD + PTO (HR = 9.16; CI, 1.8 to 15.7). Furthermore, in a cross-sectional study among patients with IgA-GN, a logistic regression model showed that the risk for homozygous DD was greater, although not at a statistically significant level in the end-stage renal failure subgroup compared with the normal renal function subgroup (odds ratio = 3.16; CI, 0.7 to 13.7) after adjustment by sex, age at biopsy, HPT, PTO, and therapy. Last, DD was significantly more frequent in those patients who started hemodialysis at an earlier age (chi2 for trend = 6.81; P = 0.009). Our study further supports that ACE genotype is a risk factor not for the development, but for the worsening of IgA-GN clinical course. However, on the basis of current knowledge, we cannot exclude that I/D polymorphism may simply serve as a prognostic marker, eventually linked with other discrete loci involved in the progression of renal damage.

Cytokine gene polymorphisms in hepatitis C virus‐related oral lichen planus

Abstract:  Cytokine polymorphisms may influence both the risk of developing oral lichen planus (OLP) and the outcome of hepatitis C virus (HCV)‐infected patients and OLP has been frequently associated with HCV infection. The aim of the present study was to analyse whether cytokine polymorphisms may influence the susceptibility to HCV‐related OLP. Thirty‐five patients with OLP and chronic HCV infection (OLP–HCV+ve) took part in the study. As controls, 44 patients with OLP but without HCV (OLP–HCV−ve) infection and 140 healthy donors were studied. Thirteen cytokine genes with 22 single nucleotide polymorphisms (SNP) were studied. IFN‐γ UTR 5644 genotype frequencies showed an increase in number of A/T heterozygote in OLP–HCV+ve patients compared with OLP–HCV−ve that approached the statistical significance [P = 0.03, P‐corrected (PC) = 0.66]. Contrarily, in OLP–HCV+ve patients, the frequency of genotype −308 G/A of the TNF‐α was decreased, whereas the genotype −308 G/G was increased compared with OLP–HCV−ve (P = 0.0005, PC = 0.011 and P = 0.0016, PC = 0.0352, respectively). OLP patients with and without HCV infection showed a different genetic cytokine background suggesting distinct pathogenetic mechanisms.

Prognostic values of soluble CD30 and CD30 gene polymorphisms in heart transplantation.

Pretransplant soluble CD30 (sCD30) is a predictor of kidney graft outcome. Its status as a predictor of heart transplant (HT) outcome has not been established. We have studied this question by assessing sCD30 levels and the number of (CCAT)n repeats of the microsatellite in the CD30 promoter region, which is able alone to repress gene transcription, in the sera of 83 HT patients and 77 of their donors. sCD30 was non-significantly increased in the patients, whereas there were no differences in the CD30 microsatellite allele frequencies. A negative correlation between the number of (CCAT)n and sCD30 levels was evident in the donors. Patients with pretransplant sCD30≤30 U/ml displayed a significantly better survival. In conclusion, sCD30 levels are predictive of HT outcome.

The distribution of KIR-HLA functional blocks is different from North to South of Italy

The killer cell immunoglobulin-like receptor (KIR)-human leukocyte antigen (HLA) interaction represents an example of genetic epistasis, where the concomitant presence of specific genes or alleles encoding receptor-ligand units is necessary for the activity of natural killer (NK) cells. Although KIR and HLA genes segregate independently, they co-evolved under environmental pressures to maintain particular KIR-HLA functional blocks for species survival. We investigated, in 270 Italian healthy individuals, the distribution of KIR and HLA polymorphisms in three climatic areas (from cold north to warm south), to verify their possible geographical stratification. We analyzed the presence of 13 KIR genes and genotyped KIR ligands belonging to HLA class I: HLA-C, HLA-B and HLA-A. We did not observe any genetic stratification for KIR genes and HLA-C ligands in Italy. By contrast, in a north-to-south direction, we found a decreasing trend for the HLA-A3 and HLA-A11 ligands (P = 0.012) and an increasing trend for the HLA-B ligands carrying the Bw4 epitope (P = 0.0003) and the Bw4 Ile80 epitope (P = 0.0005). The HLA-A and HLA-B KIR ligands were in negative linkage disequilibrium (correlation coefficient -0.1211), possibly as a consequence of their similar function in inhibiting NK cells. The distribution of the KIR-HLA functional blocks was different along Italy, as we observed a north-to-south ascending trend for KIR3DL1, when coupled with HLA-B Bw4 ligands (P = 0.0067) and with HLA-B Bw4 Ile80 (P = 0.0027), and a descending trend for KIR3DL2 when coupled with HLA-A3 and HLA-A11 ligands (P = 0.0044). Overall, people from South Italy preferentially use the KIR3DL1-HLA-B Bw4 functional unit, while those from the North Italy equally use both the KIR3DL2-HLA-A3/A11 and the KIR3DL1-HLA-B Bw4 functional units to fight infections. Thus, only KIR3DL receptors, which exert the unique role of microbial sensors through the specific D0 domain, and their cognate HLA-A and HLA-B ligands are selectively pressured in Italy according to geographical north-to-south distribution.

HLA-C/KIR GENOTYPES IN ORAL LICHEN PLANUS PATIENTS INFECTED OR NON INFECTED WITH HEPATITIS C VIRUS

OBJECTIVES Oral Lichen Planus (OLP) is associated with hepatitis C virus (HCV) infection and resembles graft-versus-host disease (GVHD) both clinically and histologically. The killer cell immunoglobulin-like receptor (KIR) genes encode a family of receptors expressed on NK and T cells and are supposed to play a significant role in GVHD and HCV infection. The aim of this study was to analyze the association among OLP, HCV infection and variants in KIR gene expression. METHODS A total of 81 patients with OLP (36 HCV+ve and 45 HCV-ve) and 217 healthy controls (HCV-ve) were typed for the presence of eight KIR genes and of HLA-Cw* alleles by polymerase chain reaction-sequence specific primer. RESULTS There were no significant differences in the frequency of the KIR genes and HLA-C1/C2 group alleles between cases and controls. We only found a significant difference in the frequency of the gene KIR2DL2 between HCV+ve and HCV-ve OLP patients. CONCLUSIONS The present data suggest that OLP is not associated with particular KIR genes or with HLA-Cw* alleles in patients without HCV infection. Contrarily, the role of the genes in OLP-HCV+ve patients remains unclear and might warrant further researches.

Association of HLA class I markers with multiple sclerosis in the Italian and UK population: evidence of two independent protective effects

Background The association of HLA A*02 with multiple sclerosis (MS) was recently confirmed by the authors, and it was observed that the combined presence of HLA Cw*05 significantly enhanced (threefold) the protective effect of HLA A*02. Objectives and methods Since A*02-Cw*05 is carried by two HLA extended haplotypes characterised by the B*4402 and B*1801 alleles, respectively, the association analysis was extended to HLA B*44 and B*18 in an Italian sample (1445 MS cases and 973 controls) and these associations were verified in a UK cohort (721 MS cases, 408 controls and 480 family trios). Results A strong protective effect, independent of DR15, of the A*02-Cw*05 combination carrying B*44 (OR 0.27, p=3.3×10-5) was seen in the Italian samples and confirmed in UK family trios (OR 0.33, p=5.5×10-4) and in a combined cohort of UK families and case–controls (OR 0.53, p=0.044). This protective effect was significantly stronger than that mediated by A*02 alone. Logistic regression showed that A*02-Cw*05 maintained a significant protection when adjusted for B alleles (Italy: OR 0.38, p=6.5×10-7; UK: OR 0.60, p=0.0029), indicating that it was not secondary to linkage disequilibrium with B*44. Different from A*02, the other HLA class I tested markers individually showed no significant (Cw*05, B*18) or a modest (B*44) protection when adjusted for the remaining markers. Conclusions This study identified at least two independent protective effects which are tagged by A*02–Cw*05 and A*02, respectively. Further studies are needed to elucidate whether this protective effect is due to the presence of an unanalysed factor characterising the HLA extended haplotype(s) carrying A*02 and Cw*05 or to a direct interaction between these alleles.

Interleukin-4RA gene polymorphism is associated with oral mucous membrane pemphigoid.

OBJECTIVE The aim of this study was to analyse whether the polymorphisms of several pro- and anti-inflammatory cytokines may influence the susceptibility to predominantly oral Mucous membrane pemphigoid (MMP) in a Northern Italian population. MATERIAL AND METHODS DNA was obtained from 41 MMP patients (29 with exclusively oral pemphigoid [OP]) and 140 unrelated bone marrow donors. Thirteen cytokine genes with 22 single-nucleotide polymorphisms (SNP) were studied by a sequence-specific PCR assay. RESULTS There was no significant difference between the patients taken together and healthy controls for any cytokine gene polymorphism studied. However, the allele A of the IL-4 receptor A (IL-4RA) was significantly more frequent in OP than controls (P < 0.05), causing an increased frequency of genotype A/A in OP patients (89.7 vs. 67.9, odds ratio: 4.11, 95% confidence intervals 1.18-14.28, P = 0.023, Pc = 0.046). CONCLUSION IL-4RA-1902 A/A genotype has been associated with a reduced response to IL-4 and has been found in 90% OP patient. Giving the supposed importance of IL-4 in MMP fibrotic process, our results can partially explain the low likelihood of scarring in OP patients.

Association of the CBLB gene with multiple sclerosis: new evidence from a replication study in an Italian population

Background The T allele of rs9657904 within the CBLB gene was recently found to be significantly associated with multiple sclerosis (MS) in a genome-wide association study in Sardinia. Objective To replicate this association in an independent population with a different genetic background. Methods The rs9657904 variant was typed in a sample of 1435 cases and 1466 controls from the Italian mainland. Results It was found that in this sample also, the common allele T of rs9657904 is significantly positively associated (one-tailed p=7.35×10-5) and with a comparable effect size with MS (OR=1.31, 95% CI 1.14 to 1.52). Conclusion These data provide further evidence of the association of MS disease with variation within CBLB.