Abstract
Transient hypogammaglobulinemia of infancy (THI) is characterized by recurrent infections and one or more reduced serum immunoglobulin levels. Typically, THI patients recover spontaneously, mostly within 30-40 months of age, but sometimes recovery may be delayed until 5-6 years of age. The use of intravenous immunoglobulin (IVIg) as an alternative to antibiotic prophylaxis remains contraversial also in symptomatic THI patients. In fact, some authors believe that IVIg therapy may cause a delay in the maturation of the humoral immune system because of the interference from passively transfered antibodies. The aim of this study was to investigate the effect of IVIg replacement on recovery from immunodeficiency in THI patients and determine new parameters in order to include these patients in IVIg therapy groups. In this retrospective study, 43 patients (65%) received IVIg replacement therapy while 23 patients (34.8%) showed spontaneous normalization without IVIg. The percentages of patients who had more than six times the number of febrile infections in a year decreased from 91% to 21% in the group receiving IVIg treatment. At admission, before being recruited to IVIg therapy, serum immunoglobulin G (IgG) levels and anti-hemophilus B (Hib) antibody titers were found to be significantly low in cases who were selected for IVIg replacement. The percentages of patients who did not have protective levels of anti-Hib, anti-rubella or anti-rubeola-IgG were also significantly high in IVIg cases. There was no statistically significant difference in the age at which IgG levels normalized between the IVIg and the non-IVIg group. Patients in the IVIg group and non-IVIg group reached normal IgG levels at the age of 42.9±22.0 and 40.7±19.8 months, respectively. In conclusion, IVIg infusions do not cause a delay in the maturation of the immune system in THI patients. Besides the well-established criteria, very low and non-protective specific antibody responses against previously applied vaccines are important factors to consider when selecting patients for IVIg therapy.