A single-center study of serum sickness caused by rabbit antithymosinglobulin therapy in children with acquired aplastic anemia

Objective To investigate the related factors of the serum sickness morbidity in the treatment of children with acquired aplastic anemia (AA) by rabbit antithymosinglobulin (ATG), summarize the clinical characte-ristics of serum sickness and evaluate the influence of serum sickness on the prognosis of AA. Methods The data of patients diagnosed as AA after treated with immunosuppressive therapy (IST) in Beijing Children′s Hospital, Capital Medical University, from March 2016 to December 2018 were collected, and the onset time, clinical manifestations, treatment, and prognosis of serum sickness were analyzed. Results A total of 48 cases were enrolled, with the median age of 5 years and 5 months (ranging from 2 years and 1 month to 15 years and 6 months), and the proportion of male to female was 1.4∶1.0, 75.0% of the patients(36/48 cases) developed serum sickness.The median onset time was the 11th day and 72.2% of the patients (26/48 cases) occurred from the 7th to the 14th day during IST.The 3 main clinical manifestations included arthralgia (63.9%, 23 cases), fever (52.7%, 19 cases) and rash (52.7%, 19 cases). There was no significant difference in peripheral blood leukocytes, neutrophils and lymphocytes between the patients with serum sickness and patients without serum sickness before IST and during serum sickness (all P>0.05). The incidence of serum sickness in children who received continuous glucocorticoid prophylaxis after IST (2/12 cases, 16.6%) was lower than that of those who did not (34/36 cases, 94.4%), and the difference was significant (χ2=29.037, P 0.05). Conclusion Children with AA are prone to develop serum sickness after IST treatment.The peak period of incidence of serum sickness is the second week during IST, and the main clinical manifestations of serum sickness include arthralgia, fever, and rash.There is no correlation between the incidence of serum sickness and the blood routine test before IST and during serum sickness.The incidence of serum sickness can be reduced by giving glucocorticoid prophylaxis, and glucocorticoid is still effective after the onset of the serum sickness.There is no correlation between the morbidity of serum sickness and the prognosis of AA treated with IST. Key words: Child; Aplastic anemia; Immunosuppressive therapy; Serum sickness