The susceptibility to develop coeliac disease (CD) has a strong genetic component, which is not entirely explained by HLA associations. Two previous genome wide linkage studies have been performed to identify additional loci outside this region. These studies both used a sib-pair design and produced conflicting results.Our aim is to identify non-MHC genetic loci contributing to coeliac disease using a family based linkage study. We performed a genome wide search in 16 highly informative multiply affected pedigrees using 400 microsatellite markers with an average spacing of 10 cM. Linkage analysis was performed using lod score and model free methods.We identified two new potential susceptibility loci with lod scores of 1n9, at 10q23n1, and 16q23n3. Significant, but lower lod scores were found for 6q14 (1n2), 11p11 (1n5), and 19q13n4 (0n9), areas implicated in a previous genome wide study. Lod scores of 0n9 were obtained for both D7S507, which lies 1 cM from the γT-cell receptor gene, and for D2S364, which lies 12 cM from the CTLA4 gene. Coeliac disease (CD) is a gluten sensitive enteropathy in which dietary exposure to wheat, barley, rye, and possibly oats results in small bowel mucosal atrophy and consequent malabsorption. There is a strong genetic component to disease development as demonstrated by a disease concordance among monozygotic twins of 70-100 % (Polanco et al. 1981 ;Salazar de Souza et al. 1987), and a 30-50 % concordance in Correspondence : Prof. PJ Ciclitira,

No abstract

This study was carried out to characterize the antibody class response by ELISA to seven Klebsiella pneumoniae serotypes (K2, K3, K17, K21, K26, K36, K50) in five different groups, 40 HLA-B27-positive ankylosing spondylitis (AS) patients, 46 patients with Crohn's disease (CD), 38 patients with ulcerative colitis (UC), 50 patients with active anti-endomysial antibody-positive coeliac disease and 40 healthy controls, using whole bacteria and capsular polysaccharide. IgG antibody levels were significantly elevated in AS patients to K17, K36, K50; IgA to K2, K3, K21, K26, K36 and K50; and IgM to serotype K21 when compared to normal controls. Furthermore, IgG antibody levels were significantly elevated in CD patients to K2, K17, K21, K26, K36 and K50; IgA to K2, K3, K21, K26, K36 and K50; and IgM to K2, K3, K17, K21 and K50. Increased IgG antibody levels in the UC group were limited only to K17, K36 and K50. No antibody class was increased to any of the K. pneumoniae serotypes in the coeliac disease group. The immune responses in AS patients also involve Klebsiella bacteria having capsular serotypes other than K26, K36 and K50. The similarity in the immune responses between CD and AS groups suggests that many AS patients may have occult bowel inflammation.

Because of the high sensitivity (approximately 95%) and technical simplicity, tissue transglutaminase antibodies may prove useful for the screening of celiac disease in population at low or medium risk of celiac disease. To avoid duodenal biopsies in patients without celiac disease, the specificity of the screening procedure may be increased by confirming with antiendomysial antibodies by immunofluorescence on human umbilical cord in individuals with results between 0.4 and 0.7 optical density.

Objectives: To verify the effectiveness of human umbilical cord (HUC) in the detection of anti-endomysial antibodies (AEA) in coeliac disease and to characterize further these antibodies by studying tissue adsorption characteristics and antibody inhibition studies. Methods: AEA were detected on HUC and primate oesophagus in a blind study, using sera from 46 patients with untreated coeliac disease and 108 controls. Tissue adsorption studies were performed using homogenized tissue from rodent liver, HUC, primate oesophagus and human liver. Sera were adsorbed with each of these homogenates and antibody was detected using HUC, primate oesophagus and rat kidney. In the inhibition experiments AEA was detected on HUC, and inhibition of binding was attempted by pre-incubating the sections with antibodies against collagen types I, III and IV. Results: The sensitivity of AEA was 91% when detected on HUC, 89% when detected on primate oesophagus (93% and 91%, respectively, after exclusion of 1 patient with IgA deficiency). Specificity was 100% for both assays. Tissue adsorption studies showed identical results for AEA detected on both HUC or primate oesophagus, whereas antireticulin antibody was adsorbed only by rodent tissue. Blocking of the HUC with anticollagen antibodies did not prevent binding of AEA. Conclusions: HUC is an effective substrate for the detection of AEA and may be superior to primate oesophagus. The antibody detected by HUC shows identical tissue adsorption specificities to that detected on primate oesophagus.