New insights into childhood Vernal keratoconjunctivitis-associated factors.

The purpose of this study was to test for detectable serum levels of antibodies usually associated with immune-related diseases in children with Vernal keratoconjunctivitis (VKC) and seek for their family history of allergies and autoimmune disorders. The association of human leukocyte antigens (HLA) with VKC was also investigated. We enrolled 181 VKC children and assessed total and specific IgE, antithyroglobulin (AbTG), antithyroidperoxidase (AbTPO), antitransglutaminase (tTG), and antinuclear antibodies (ANA) by standard procedures. Class I and II HLA typing was also carried out following standard protocols, and it was compared with that of healthy subjects. Patients were positive for AbTG (22%), AbTPO (14.6%), and ANA (15.8%), and AbTG positivity was associated with VKC severity (mean ocular score ± SD positive vs. negative: 6.56 ± 2.1 vs. 4.82 ± 2.1; p = 0.03). We found that 12.2% of VKC cases had a positive family history for psoriasis, 6.4% for other cases of VKC, and 5.2% for thyroiditis, while 50.2% of them were atopic. The expression of HLA class I B37 was significantly higher in VKC patients than in controls (7.1% vs. 2.1%, p = 0.04), although not confirmed after multiple antigens testing analysis. Our study suggests a role of common components associated with immune-based diseases in the clinical expression of VKC.

Formation of anti-platelet factor 4/heparin antibodies after cardiac surgery: influence of perioperative platelet activation, the inflammatory response, and histocompatibility leukocyte antigen status.

BACKGROUND: Anticoagulation therapy with heparin induces antibodies that recognize multimolecular complexes of platelet factor 4 bound to heparin (anti-platelet factor 4/heparin antibodies). Considering that cardiac surgery induces an intense platelet activation and proinflammatory response, we examined the relationship between formation of anti-platelet factor 4/heparin antibodies and plasma levels of platelet factor 4 and interleukin 6. We also examined the relationship between anti-platelet factor 4/heparin seroconversion and the histocompatibility leukocyte antigen system. METHODS: In 71 patients undergoing cardiac surgery, anti-platelet factor 4/heparin antibody levels were evaluated by means of enzyme-linked immunosorbent assay preoperatively and 14 days postoperatively. Platelet serotonin release assays were performed to assess the platelet-activating potential of the antibodies. Plasma levels of platelet factor 4 and interleukin 6 were assayed at prespecified time points. Histocompatibility leukocyte antigen status was assessed preoperatively in all patients and was compared with that of 6156 healthy subjects. RESULTS: Thirty-seven (52%) patients had anti-platelet factor 4/heparin antibodies with an OD value of 0.45 or greater in 1 or more of the assays. Applying strict seroconversion criteria (>2-fold increase in Optical Density), only 16 (22.5%) patients had evidence of anti-platelet factor 4/heparin antibody seroconversion after the operation. Neither the presence of anti-platelet factor 4/heparin antibodies nor seroconversion influenced postoperative outcomes. The CW4 allele was significantly more frequent among seroconverted patients (46.9% vs 19.1%, P = .002). Platelet factor 4 levels did not influence seroconversion. Patients with anti-platelet factor 4/heparin levels of 0.45 OD units or greater 14 days after the operation had significantly higher interleukin 6 levels measured 1 hour after protamine administration. DISCUSSION: Patients with a greater amount of perioperative inflammation could be more likely to have anti-platelet factor 4/heparin antibodies 1 to 2 weeks later. We provide additional evidence that the histocompatibility leukocyte antigen CW4 confers genetic susceptibility in an acquired inflammatory disorder that includes the anti-platelet factor 4/heparin immune response.

HLA-Cw allele frequencies in northern and southern Italy.

The evidence for HLA-Cw antigens' involvement in the modulation of the immune response in bone marrow transplantation, NK alloreactivity and the susceptibility and follow-up for different diseases has been growing in the recent years, but very few data on HLA-Cw distribution in healthy Italian subjects are available to date. This report presents an updated description of HLA-Cw frequencies in Italy, comparing data from the northern (Lombardia) and southern (Campania and Puglia) parts of the country. A total of 1101 healthy subjects of Italian origin were genotyped, and the results showed that HLA-Cw*04, Cw*07, Cw*12, and, in particular, Cw*0401, Cw*0701, Cw*1203, were the most frequent alleles found in all three regions analysed. Nevertheless, statistically significant differences were observed in Cw*07 distribution, which was more frequent in the southern than in the northern part of Italy (28.8% vs 22.4%; p=0.001; OR: 1.4; 95%CI: 1.14-1.73), and in Cw*12 distribution, which was more frequent in the north than the south (17.0% vs 12.4%; p=0.007, OR: 1.4; 95%CI: 1.10-1.91). These results, which give an improved pattern of distribution of HLA-Cw alleles in the Italian population, would be useful in bone marrow transplantation and anthropological studies. Moreover, due to the important role of HLA-Cw antigens in modulation of the immune response and NK alloreactivity, these data would be of interest in studies on susceptibility, follow-up and/or protection against different diseases.

Influence of HLA antigens and OSAS in childhood: a preliminary report.

Several studies have emphasized the role of familial factors and familial aggregation in increasing susceptibility to obstructive sleep apnea syndrome (OSAS); the aim of the present study was to investigate the possible influence of human leukocyte antigen (HLA) in the development of sleep disordered breathing and OSAS of children. Between January 2000 and January 2003, all the 370 children [193 males; median age: 5.2 years (range: 1-12 years)] with sleep disordered breathing referred to our Center were screened by a 41-item multiple-choice questionnaire. All habitual snores children underwent a polisomnographic evaluation, and those with an apnea/hypopnea index >3 were diagnosed as having OSAS. All children with OSAS or primary snoring were HLA typed for class I and II. According to nocturnal polygraphic monitoring study, 41 patients were diagnosed as having OSAS and 32 as primary snoring. Patients in the two diagnostic groups were homogeneous for demographic and clinical characteristics. HLA-B65 was found to be significantly more expressed in children with sleep disordered breathing as compared with controls (10.5% versus 3.61; Pypc < 0.04) while no difference was found for the other tested antigens. A logistic regression analysis found cough (P < 0.02) and persistent wheeze (P < 0.008) the sole risk factors for OSAS development. Our preliminary data suggest that HLA does not play a key role in the pathogenesis of OSAS, however more studies are needed to clarify this issue.