Immunoglobulin subclasses and prophylactic use of immunoglobulin in immunoglobulin g subclass deficiency

Abstract

Persistent low serum levels of one or several immunoglobulin G (IgG) subclasses can be found in a high proportion of adult patients with increased susceptibility to infections. It is hard to envision that the low subclass level in itself is responsible for this susceptibility because healthy blood donors have been described who are completely devoid of certain subclasses in serum. This apparent discrepancy may be partly explained by the observation that most subclass‐deficient patients have underlying aberrations in T‐cell and B‐cell interaction and function that may impair their capacity to compensate for even minor deficiencies. A prospective blind crossover study of the effect of prophylactic Ig substitution therapy was done in 43 adult patients with IgG subclass deficiency. The patients were randomized to receive 1 year of therapy with intramuscular Ig 25 mg/kg/wk or 1 year of saline injections. A significant protective effect of the prophylactic Ig therapy was seen with a great reduction in the number of days of infection. In addition, several immunologic parameters were altered after 1 year of Ig therapy. Nineteen of the patients later were included in an open study using 50 mg/kg/wk of Ig. After 6 months of treatment, significant protection against infection was observed, with a reduction of 6.2 days in the number of days per month with infection. This marked effect of prophylactic Ig suggests that the Ig aberrations seen in IgG subclass‐deficient patients contributed to their susceptibility to infection. The effect of 25 mg/kg/wk was much less pronounced than that of 50 mg/kg/wk, and normal serum IgG subclass levels were not achieved even during the higher‐dose therapy. However, it seems likely that subcutaneous or intravenous administration of larger doses of Ig would allow for more efficient therapy.

Immunoglobulin G Subclass Deficiency is the Major Phenotype of Primary Immunodeficiency in a Korean Adult Cohort

“…These results are consistent with previous studies that have reported IgG subclass deficiency in patients with bronchial asthma or obstructive lung disease (16-18). Other studies have revealed that more than 40% of subjects with IgG3 subclass deficiency have a history of asthma (19) and 41-50% of severe asthmatic children showed IgG3 subclass deficiency (16). Low levels of IgG subclasses have been associated with an increased susceptibility to respiratory infections, especially during primary immune responses to viral protein antigens.…”

“…The treatment of choice for antibody deficiency is intravenous immunoglobulin (IVIG) replacement therapy (19, 29, 30). Adequate replacement of IVIG has been shown to reduce the incidence of pneumonia and prevent the progression of lung disease in patients with PID.…”

Primary IgA and IgG subclass deficiency in a 17-year-old Pakistani girl: a case report

“…Studies have shown the useful role of regular IVIG therapy for prophylaxis against infections [9,10]. However, in developing countries, regular therapy is difficult because of issues such as cost, brief hospital admission required for administration of immunoglobulins, patient compliance with scheduling and possibility of contamination of the product given [10].…”

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

“…6,38,39 Silk et al 40 reported that in children with IgG2 subclass and specific antibody deficiency who failed to improve after a 12-month period of prophylactic antibiotic therapy with trimethoprim-sulfamethoxazole, IVIG therapy significantly decreased the number of episodes of recurrent sinopulmonary infections. Similarly, Bernatowska-Matuszkiewicz et al 39 demonstrated the clinical efficacy of IVIG in pediatric patients with severe pulmonary inflammatory disease and IgG3 subclass deficiency by decreasing the duration of hospitalization and use of antibiotics and steroids.…”