Pre-treatment Neutropenia in Children and Adolescents with Autoimmune Hyperthyroidism

Abstract

Objective: Neutropenia can occur in untreated autoimmune hyperthyroidism (AIH) or in association with treatment with the anti-thyroid drug, methimazole (MMI). Starting MMI in children and adolescents with AIH and pre-existing neutropenia could thus be worrisome. The aim was to describe the prevalence of neutropenia in pediatric AIH, prior to antithyroid drug therapy and to assess the effect of antithyroid drugs on neutrophil count. Methods: Patients with AIH attending a pediatric endocrinology clinic were retrospectively reviewed. Absolute neutrophil count (ANC) data at presentation and during anti-thyroid treatment for up to 24 weeks was collected. AIH was defined as elevated free thyroxine (fT4) or free tri-iodothyronine (fT3), suppressed thyroid stimulating hormone, and positive thyroid autoantibodies. Neutropenia was defined as ANC <1500 cells/μL. Results: Thirty-one patients (71% female) were included with a median interquartile range (IQR) age of 14.71 (11.89-17.10) years. Neither fT4 nor fT3 levels correlated with ANC at presentation (r s =0.22, p=0.24 and r s =0.13, p=0.54, respectively). 26/31 (84%) had normal baseline ANC. None developed neutropenia with thionamides. 5/31 (16%) had baseline neutropenia (median ANC 1,200/μL; IQR 874-1200). Four of these five started MMI at diagnosis while one was started on propranolol only but MMI was started one week later. All five normalized ANC within 24 weeks. Conclusion: In this cohort, 16% of AIH patients had neutropenia at presentation, but this resolved in the short term and did not worsen with thionamides. Thionamides may be used with caution in these patients with close monitoring of blood counts.

Characteristics of Graves' disease in children and adolescents in Nanjing: A retrospective investigation study

“…Studies in adult patients with GD indicated that anti-thyroid drugs and GD per se may cause hematological abnormalities, including anemia, leukopenia, thrombocytopenia, and pancytopenia ( 19 , 40 , 41 ). There have been few relevant studies in children and adolescents.…”

“…However, the sample size limits relevant studies in the pediatric population. In addition, abnormal peripheral blood cells, such as leukopenia or granulocytopenia, also require concern in the GD pediatric population ( 19 ).…”

Clinical characteristics of neutropenic patients under antithyroid drug: Twelve-year experience in a medical center

“…Disease-related neutropenia is commonly observed (10%-16%) in patients with newly diagnosed hyperthyroidism. 5,15,16 In patients treated with ATDs, neutropenia may also develop due to concurrent chemotherapy, infection, and inflammation, as well as the presence of hematological, hepatic, or autoimmune diseases. 17 Three ATDs are included among the 11 most common nonchemotherapy drugs that induce agranulocytosis.…”