bubble_chart Overview

Transient hypogammaglobulinemia is a self-limiting condition that can affect both males and females. In normal infants, approximately 90% of maternal IgG transferred through the placenta is metabolized by about 3 months after birth, while the ability to synthesize and secrete IgG gradually increases. Affected infants often delay IgG production until 9 to 15 months of age, reaching normal IgG levels by 2 to 4 years of age. After recovery, the condition does not recur, and there are no persistent immune system abnormalities.

bubble_chart Etiology

The cause of the disease

The cause of the disease is still not entirely clear. Some propose that certain fetal IgG genetic factors, specifically the allotypic antigens of the Gm system, stimulate the maternal immune system, leading to the production of anti-Gm antibodies. These antibodies cross the placenta and enter the fetus, inhibiting immunoglobulin (Ig) synthesis. Subsequently, the anti-Gm antibodies in the infant's circulation gradually decrease due to catabolism, while the infant's own Ig synthesis gradually increases. Another perspective suggests that the fetus may acquire a large amount of an immunosuppressive substance from the mother but fails to inactivate it. Additionally, premature infants are more prone to developing this condition. There are also reports of occasional familial cases, where siblings of children with severe combined immunodeficiency sometimes exhibit transient hypogammaglobulinemia, indicating that the disease may also involve defective genes. Others believe that this condition represents a prolonged physiological hypogammaglobulinemia phase.

bubble_chart Clinical Manifestations

Sick children often seek medical attention due to frequent common colds or recurrent diarrhea. Most affected children do not suffer from severe infections, but bacterial infections can persist and even impair growth and development. Common infections may involve the skin, lungs, meninges, etc., with pathogens mostly being Gram-positive bacteria. Serum IgG is less than 2.5g/L (250mg/dl), while IgA and IgM levels are normal or reduced. The number of B lymphocytes in the blood circulation is normal. Cellular immune function is also normal.

bubble_chart Treatment Measures

Treatment Instructions

Intravenous immunoglobulin (IVIG) is beneficial for symptom control. Treatment should continue until the child's immune function returns to normal. Some consider this disease self-limiting, and IVIG may not be necessary when the infection is mild. Appropriate antibiotic therapy is required when bacterial infection is present.