Molecular biology of coeliac disease

Association of human leucocyte-DR and DQ antigens in coeliac disease: a family study

BACKGROUND AND AIMS

No family studies regarding the association of coeliac disease with the human leucocyte antigen (HLA)-DQ locus are available. Moreover, no HLA studies have been carried out in coeliac disease patients from India. The aim of this study was to study the HLA class II (DR and DQ) antigens in children with coeliac disease and in their first-degree relatives.

METHODS

Fifteen children with coeliac disease and their first-degree relatives (birth parents of all the coeliac disease patients and fifteen siblings) were studied. A group of 123 healthy unrelated and ethnically matched subjects were used as controls. The HLA-DR and -DQ typing was carried out by a complement-dependent microlymphocytotoxicity assay. The transmission disequilibrium test was used for analysis of results.

RESULTS

There was no association of coeliac disease with DR phenotypes. Ninety-three per cent of patients (14/15) carried the DQ2 allele. DQ2 was transmitted in 15 of 19 informative cases (transmission probability of 79%, chi2 6.368 with 1 df, nominal P=0.012 and P value corrected for multiple test=0.035). The haplotype relative risk associated with DQ2 was 5.71 (95% confidence interval 1.71-16.28).

CONCLUSION

Coeliac disease in Indian children is predominantly associated with HLA-DQ2.

Correlation of clinical characteristics and small bowel histopathology in celiac disease

BACKGROUND

Literature information regarding clinical and histological correlates in celiac disease is limited. The present study was designed to assess the value of various clinical parameters in predicting the severity of small bowel histopathology.

METHODS

Small bowel biopsy specimens of 59 children with established celiac disease (ESPGAN criteria) were evaluated blindly. Morphology was evaluated based on a common histopathology score. The following clinical variables were evaluated: age at diagnosis, duration of symptoms, severity score of clinical symptoms, severity score of physical signs, and growth parameters (height and weight Z scores). Multiple regression analysis was performed to evaluate the relative importance of each clinical parameter.

RESULTS

Only three clinical variables revealed a significant correlation with the histopathology score. The symptom severity score (t = 3.883, p = 0.0003) demonstrated a positive correlation. The two others, age at diagnosis (t = 3.076, p = 0.0032) and duration of symptoms (t = -2.987, p = 0.0041), revealed a negative correlation.

CONCLUSIONS

We conclude that more severe clinical symptoms of a shorter duration, presented at a younger age, are better predictors of a more severe form of small bowel histopathology in children with celiac disease.

[Celiac disease, cerebral calcifications and epilepsy syndrome]

The syndrome of coeliac disease, epilepsy and cerebral calcifications is a rare complication of coeliac disease. The pathological changes consist in a patchy pial angiomatosis and resemble those of Sturge-Weber syndrome, whose variant without port-wine angioma must be ruled out. Typical course includes three stages leading to a severe encephalopathy. However, the mental impairment is extremely variable. The pathogenetic process is so for unknown; main clues involve a chronic folic acid deficiency or a HLA-related autoimmune disorder. Treatment requires early gluten-free diet and anti-epileptic drug.