Original Article

Pre-treatment Neutropenia in Children and Adolescents with Autoimmune Hyperthyroidism

10.4274/jcrpe.galenos.2020.2020.0184

  • Melissa Kaori S. Litao
  • Ana Gutierrez Alvarez
  • Bina Shah

Received Date: 29.07.2020 Accepted Date: 12.11.2020 J Clin Res Pediatr Endocrinol 0;0(0):0-0 [e-Pub] PMID: 33261249

Objective:

Neutropenia can occur from untreated autoimmune hyperthyroidism (AIH) or methimazole (MMI); starting MMI in children and adolescents with AIH and neutropenia could thus be worrisome. We aimed to describe the prevalence of neutropenia in children and adolescents with AIH prior to treatment with antithyroid drugs and to assess the effect of antithyroid drugs on the neutrophil count.

Methods:

This was a retrospective study of patients with AIH seen at a Pediatric Endocrinology clinic. ANC data at presentation and during anti-thyroid treatment for up to 24 weeks was collected. AIH was defined as elevated fT4 or fT3, suppressed TSH, and positive thyroid autoantibodies. Neutropenia was defined as ANC <1500 cells/μl.

Results:

31 patients were included: 71% females, 29% males, median age 14.71 years (IQR 11.89-17.10). Neither fT4 nor fT3 levels significantly correlated with ANC at presentation (rs = 0.22, p = 0.24 and rs = 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 1,200/μl; IQR 874-1200); 4/5 patients started MMI at diagnosis; 1/5 started propranolol only then added MMI 1 week later; all normalized ANC within 24 weeks.

Conclusion:

A small percentage of AIH patients may have neutropenia at presentation, but it resolves in the short term and does not worsen with thionamides. Thionamides may be used with caution in these patients with close monitoring of blood counts.

Keywords: Hyperthyroidism, neutropenia, thionamides, methimazole, agranulocytosis