Comparison of Serum Immunoglobulin Levels and Lymphocyte Counts in Children with Lymphadenitis Following BCG Vaccination

Lymphadenitis is the most common complication following BCG vaccination observed in 0.1% to 1% of children.

The presence of immunodeficiency can increase the probability of lymphadenitis or contribute to its exacerbation, so the early detection of immunodeficiency in those developing lymphadenitis can help prevent its many catastrophic complications.

This study was performed on patients referred to Taleghani Hospital of Gorgan city in 1396. Forty children with lymphadenitis and 40 healthy children entered the study. Serum samples were taken to measure white blood cell counts and the antibodies, including IgE, IgG, IgM, and IgA. Purified protein derivative (PPD) test was done in both groups.

In this study, there were 40 patients with lymphadenitis, of whom 24 were boys (60%), and 16 were girls (40%), and in the control group were 22 boys (55%) and 18 girls (45%). There was no statistically significant difference between the two groups. Lymphadenitis was ipsilateral to the vaccine injection site in all 40 cases, and it was in the anterior axillary region in 82%. Abscess at the lymphadenitis site occurred in 25% of cases. The mean size of induration following PPD in the lymphadenitis group was larger than the control group (5.86 mm and 3.04 mm, respectively) (P = 0.004). There were five patients (12.5%) under one year of age with lymphopenia (lymphocyte count > 3,000), but no lymphopenia was observed in the control group. The mean average IgA and IgM levels were different between the case and control groups (P = 0.001), (P = 0.016), respectively. There was no statistical difference in IgG and IgE levels between both groups (P = 0.92 and P = 0.762, respectively).

This study shows that the size of indurations following PPD injection is higher in those with post-vaccination lymphadenitis. Although the probability of a primary immunodeficiency disorder in the cases of our study was low considering the normal immunoglobulin levels and CBC report, further studies with a larger sample size and more specific investigations, such as flow cytometry and specific antibody response, are needed.