Does OM-85 BV prophylaxis trigger autoimmunity in IgA deficient children?

BACKGROUND: IgA deficiency (IgAD) is the most common primary antibody deficiency. Although two-third of the cases are reported to be asymptomatic, some IgAD children may have frequent infections that urge the clinicians to search for prophylactic measures. OM-85 BV is one of these agents that is known to stimulate mucosa associated lymphoid tissue, and upregulate Th-1 response. This study was performed to determine a possible role of OM-85 BV in triggering autoimmunity in IgAD children within a four-year-follow up period.

METHODS: Sixty-three children (34 males (54%), 29 females (46%)) with sporadic IgAD and recurrent febrile infections were included. Patients were carefully screened for autoimmunity both on admission and in follow-up: Those with autoimmune features or under immunosuppressant treatment were excluded. Patients were randomly divided into two groups: Group I received bacterial lysate propylaxis (OM-85 BV) (n:37), and Group 2 received no prophylactic regimen (n:26). Development of clinical autoimmune findings or autoantibodies (anti-nuclear antibody (ANA), ANA profile (14 antigens), anti-cytoplasmic antibodies (ANCA), anti-cardiolipin antibodies IgG and IgM (aCL), rheumatoid factor (RF), direct Coombs test, anti-thyroglobulin (anti-T) and anti-thyroid microsomal antigen (anti-M)) were evaluated.

RESULTS: Mean age of the study group, age at the onset of infectious symptoms and at admission were 102.9±42.2, 27.1±24.9, and 55.2±25.1 months, respectively. Follow-up duration of the whole study group was 48.3±23.1 months. Number of infections was 6.2±2.7 per year in the whole study group. Sixteen patients (25.4%) of the whole study group showed ANA positivity in different patterns and titers. Frequency of ANA, ANCA and RF positivity was 24.3%, 5.4%, 2.7% in Group 1, and 26.9%, 11.5%, 3.8% in Group 2, respectively. Statistical comparisons revealed no significant difference between the two groups.

CONCLUSION: Significant clinical or laboratory markers for autoimmunity in follow-up were not observed between receivers or non-receivers of OM-85 BV. Frequency of ANA positivity was comparable to the previously reported values in IgAD children which was not affected by OM-85 BV usage. Possible effect of triggering autoimmunity with repeated cures of bacterial lysates needs to be further clarified. Side effects requiring the cessation of treatment were not recorded.