Milk precipitins in selective IgA deficiency.

Area of Science:

• Immunology
• Gastroenterology
• Allergy and Immunology

Background:

• Selective IgA deficiency (sIgAD) affects 40-50% of patients with precipitating antibodies to cow's milk antigens, commonly bovine IgM.
• These antibodies can interfere with the diagnosis of sIgAD using radial immunodiffusion by creating false positive anti-antiserum precipitin rings.
• Potential predisposing factors include abnormal immunoregulatory function and increased absorption of milk antigens when secretory IgA is absent.

Purpose of the Study:

• To investigate the prevalence and diagnostic implications of cow's milk antibodies in selective IgA deficiency.
• To explore the potential role of immunoregulatory dysfunction and milk antigen absorption in the development of these antibodies.
• To assess the effect of dietary cow's milk elimination on the presence of these antibodies.

Main Methods:

• Radial immunodiffusion assays were used to detect precipitating antibodies to cow's milk antigens.
• Patient cohorts with selective IgA deficiency were analyzed for the presence of these antibodies.
• Dietary elimination of cow's milk was implemented in a subset of patients.

Main Results:

• Precipitating antibodies to cow's milk antigens (bovine IgM) were detected in 40-50% of patients with selective IgA deficiency.
• The presence of these antibodies was found to interfere with the accurate diagnosis of selective IgA deficiency.
• Elimination of dietary cow's milk led to the disappearance of these specific antibodies.

Conclusions:

• Cow's milk antibodies are common in selective IgA deficiency and can complicate diagnosis.
• Abnormal immune regulation and increased milk antigen absorption may contribute to their formation.
• Dietary intervention by eliminating cow's milk can resolve the presence of these antibodies.