Dwindled serum IgG levels of Rubella, Diphtheria toxin, Hepatitis B virus and Tetanus Toxoid after chemotherapy; a report from Iranian children with malignancy

Epigenetic regulation such as DNA methylation plays a major role in chromatin organization Background:Chemotherapy suppresses immunoglobulin production as a result of cell toxicity. Decreased immunoglobulin levels can result in the onset of opportunistic infections. The aim of the current study is to compare the immunoglobulin G (IgG) levels of the selected vaccine-preventable disease (VPD) before and six months after chemotherapy in a group of Iranian children with malignancies.

In this interventional study, serum levels of Rubella, Diphtheria toxin, Hepatitis B virus (HBV), Tetanus Toxoid, Mumps, and Measles IgG were measured in 30 children with malignancy and previously vaccinated for these diseases. Six months after chemotherapy, serum IgG levels were reassessed and compared with their corresponding pre-chemotherapy levels.

In this study, 17 (56.7%) male and 13 (43.3%) female were included. The mean age was 7.69±3.09 years. After chemotherapy, Rubella IgG levels dropped from 73.88±85.11 to 56.59±72.84 IU/mL (P<0.05; r= 0.956; 33.4% become serum negative (SN)). Diphtheria toxin IgG was diminished from 0.683±0.454 to 0.174±0.248 IU/mL (P<0.05; r=0.601; 26.7% SN). Anti-HBV IgG showed a reduction from 46.26±101.56 to 25.56±80.49 IU/mL (p<0.05; r= 0.524; 60% SN) and Anti-Tetanus Toxoid IgG fell down from 1.031±0.582 to 0.321±0.408 IU/mL (p<0.05; r= 0.365; 33.4% SN). Anti-Measles and Anti-Mumps IgGs showed no significant change (p>0.05).

Pediatric chemotherapy was associated with dropped serum IgG levels of most VPDs. A good correlation was also observed between serum levels of IgG before and six months after chemotherapy. Revaccination of children with malignancies may be necessary upon declined serum IgG titers.