Immunological aspects of diagnosis of celiac sprue in children.
Serum anti-gluten (AGA) and anti-reticulin (ARA) antibodies were examined in children suffering from celiac sprue (CS); cellular hypersensitivity to gluten was tested and secretion of immunoglobulins and anti-gluten antibodies into the culture medium after 24-hour in vitro cultivation of jejunal mucosal biopsies was investigated with the aim to assess significance of these methods for CS diagnosis. Indirect immunofluorescence was used in ARA determination, ELISA method for AGA determination, cellular hypersensitivity was examined using the test of leucocyte migration inhibition (LMIT) with gluten. ARA were detected in 69% of children with untreated CS and in 28% of CS children who were on a gluten-free diet. ARA specificity was 100%. Statistically significant higher titres of IgG AGA and IgA AGA were proved in children with untreated CS as compared with the control group. IgA AGA were detected significantly more frequently than IgG AGA. No relationship between positive AGA and the degree of alteration of the jejunal mucosa was found. IgG AGA sensitivity in CS children with pathological findings on the jejunal mucosa was 52%, specificity being 95%. IgA AGA sensitivity was 82% with specificity 90%. After a parallel application of IgA AGA and ARA, sensitivity of the tests rose up to 95.5%, specificity being 90%. Examinations of ARA and AGA have a significant importance for laboratory tests used for screening children with pathological findings on the jejunal mucosa and for indication to jejunal biopsies. The above tests do not replace jejunal biopsy in CS diagnosis. They can be applied in monitoring children with CS during gluten challenge and in checking how the gluten-free diet is observed. Significantly higher stimulation of leucocyte migration in gluten environment was proved in children suffering from CS as compared with the control group. Stimulation of migration is supposed to indicate cellular hypersensitivity to the antigen used in CS children. After a 24-hour culturing of jejunal mucosal biopsies, significantly elevated concentrations of IgA immunoglobulin and IgG, IgA and IgM AGA were found in the culture medium as compared with those obtained from cultured jejunal mucosal biopsies of control group children. The test of leucocyte migration inhibition and in vitro culturing of jejunal mucosa are quite complex and exacting methods when used in routine practice. Their significance lies in the fact they enable us to study in vitro immunological reactions in children suffering from celiac sprue.