A case of paroxysmal cold hemoglobinuria with a positive Donath-Landsteiner test result for more than 7 months

Abstract

A 3-year-old male visited our hospital owing to fever and passing red urine in December 20XX. Initial blood tests showed a hemoglobin level of 9.0 g/dL, a reticulocyte count of 1.6%, a lactate dehydrogenase level of 850 U/L, and a haptoglobin level of less than 2 mg/dL. Direct Coombs and Donath-Landsteiner (D-L) tests yielded positive results. He was diagnosed as having paroxysmal cold hemoglobinuria (PCH). The patient recovered by avoiding cold stimulation, but the D-L test result remained positive and was only confirmed to be negative 10 months after the disease onset. The D-L test usually shows a negative result in most cases of PCH 7 months after the onset of the disease, but in this case, the test result was positive for more than 7 months, making this a rare case.