Prospective, randomized comparison of OM-85 BV and a prophylactic antibiotic in children with recurrent infections and immunoglobulin A and/or G subclass deficiency.

BACKGROUND

Patients with immunoglobulin (Ig)A and/or IgG subclass deficiency may be asymptomatic or may have recurrent, mainly respiratory infections.

OBJECTIVE

This study compared the clinical efficacy and tolerability of prophylactic therapy with either the oral immunomodulator bacterial extract OM-85 BV or benzathine penicillin G (BPG) in the prevention of recurrent infections in symptomatic patients.

METHODS

In this 26-month, prospective, randomized study conducted at the Department of Pediatric Immunology, Ege University (Izmir, Turkey), children aged 1 to 12 years with recurrent infections and IgA and/or IgG subclass deficiency were enrolled. After an initial 12-month control period, patients were randomized to receive OM-85 BV or BPG. OM-85 BV (3.5-mg capsule) was given once daily for the first 10 days of each month for the first 3 months of the study. IM injections of BPG were given at a dose of 1.2 million units (for patients with body weight > 27 kg) or at a half-dose (for patients with body weight ≤27 kg) every 3 weeks for 12 months. In nonresponders (ie, those who continued to have recurrent infections at 12-month follow-up), IV immunoglobulin (IVIG) replacement therapy at 400 mg/kg body weight was given every 4 weeks for an additional 12 months. The results of IVIG therapy were assessed by the authors using clinical observation. Adverse effects and adverse drug reactions were documented by the authors for each vaccine, prophylactic therapy, and IVIG.

RESULTS

A total of 91 children (56 boys, 35 girls; mean [SD] age at the start of the control period, 46.4 [31.0] months) were enrolled. Of these, 44 were randomized to the OM-85 BV group and 47 to the BPG group. The year before prophylactic therapy, the mean (SD) number of reported infections was 10.7 (3.6) and the mean (SD) number of antibiotic courses was 9.7 (3.6) (OM-85 BV group: mean [SD] number of reported infections, 10.5 [3.3]; mean (SD) number of antibiotic courses, 9.3 [3.3]; BPG group: mean [SD] number of reported infections, 10.8 [3.9], mean (SD) number of antibiotic courses, 10.1 [3.9]). At 12 months, the number of infections and antibiotic courses decreased significantly in the entire study population, but the between-group difference was not significant. Five patients in each group (OM-85 BV group, 11.4%; BPG group, 10.6%) were considered nonresponders and received IVIG treatment. Compared with responders, nonresponders were significantly younger (mean [SD] age, 34.40 [21.70] months vs 52.65 [30.52] months; P = 0.036) and had lower serum IgG (P<0.001), IgG1 (P = 0.006), IgG2 (P = 0.003), IgG3 (P = 0.035), and IgM (P = 0.008) levels and antibody responses to tetanus toxoid and Haemophilus influenzae type b (Hib) vaccines (P = 0.036 and 0.013, respectively). At 12-month follow-up, a protective effect of the prophylactic IVIG therapy was seen, with a statistically significant reduction in the number of infections to 3.3 (2.4) and in the number of antibiotic courses to 2.7 (2.5) (both P = 0.005).

CONCLUSIONS

In this study population of children with recurrent infections and IgA and/or IgG subclass deficiency, prophylactic therapy with either OM-85 BV or an antibiotic significantly decreased the number of infections per year. In addition, nonresponders benefited from IVIG replacement therapy.