Evaluation of Hypersensitivity Reactions in Pediatric Patients Using Biological Drugs.

INTRODUCTION: Biological drugs are currently used for the treatment of chronic inflammatory, autoimmune, and neoplastic diseases. With their expanding indication spectrum and increasing use, hypersensitivity reactions to these drugs are also becoming more frequent. The present study aimed to report the incidence and the features of such reactions in pediatric patients using biologicals for the treatment of various diseases. METHODS: The medical records of pediatric patients treated with biological agents between October 1, 2011 and August 31, 2019 were reviewed and adverse reactions were evaluated retrospectively. RESULTS: During the study period, 211 patients (116 boys, 55%) used 21 different biological drugs for the treatment of various diseases. Their median age at the time of the first treatment was 139.9 (IQR: 92.2-187.8) months. Hematologic-oncologic diseases were the most common indication for biological therapy (97/211; 46.0%), followed by rheumatologic diseases (82/211; 38.9%). Of the 211 patients, 14 (6.64%) experienced reactions to biological drugs. The most common culprit agent was rituximab (57.1%). Most of the patients (85.7%) had a history of reactions either during the infusion or within 1 h after taking the drug. Five patients underwent desensitization to the culprit drug, while 7 other patients continued treatment with a reduced dose/infusion rate or premedication. Also 1 patient continued to take the drug without any additional treatment. CONCLUSION: It was reported that 6.64% of the patients who received biologic drug therapy for various reasons in our hospital had hypersensitivity. The most common culprit agent was rituximab, and most of the reactions were immediate reactions.

The impact of pretreatment serum cobalamin and folate levels on complications and peripheral blood recovery during induction chemotherapy of leukemia: a cross-sectional study.

OBJECTIVES: We aimed to evaluate the impact of pretreatment folate and vitamin B12 deficiencies on the frequency of complications and peripheral blood recovery, in children with acute lymphoblastic leukemia (ALL). METHODS: Pre-induction serum folate and vitamin B12 levels of 88 newly diagnosed ALL patients were evaluated retrospectively. Folate < 3 ng/mL and vitamin B12 < 200 pg/mL were accepted as deficiency. Median hemoglobin, absolute neutrophil count (ANC), and platelet counts, transfusion needs, and complications such as mucositis, febrile neutropenia (FN), bleeding at diagnosis, at 15th and 33rd day of induction, were assessed. Recovery of peripheral blood count, which was defined as an ANC > 1.0 × 109/L and platelet count > 100 × 109/L at 33rd day of chemotherapy were also evaluated. RESULTS: Folate or vitamin B12 deficiencies were observed in 21 (23%) and 40 (45%) children, respectively. Peripheral blood counts, complications rates, and transfusion needs were not statistically different between deficient and normal level groups during induction. The number of febrile days, though not statistically significant, was higher in the both deficient groups. Seventeen of 40 (42.5%) patients with vitamin B12-deficient and 12 of 21 (57.1%) folate-deficient patients experienced at least one episode of FN during induction. FN was more common in folate-deficient group, but that was not statistically significant. Complete peripheral blood recovery at 33rd day of induction was seen in 40% in the vitamin B12-deficient group and 28.6% in folate-deficient group. Peripheral blood recovery rate at day 33 was also similar in both deficient and normal level groups. CONCLUSION: Although pre-induction low serum levels of vitamin B12 and folate did not have statistically significant impact on disease-/treatment-related complications and peripheral blood recovery at induction, the frequency of FN and number of febrile day were higher in both deficiencies and folate-deficient patients, respectively.