High peak of carbamylated hemoglobin discordant with urea level: a case report

Siti N Ab-Rahim,Tuan S Tuan-Ismail,Hanim A Ibrahim,Mohd N Hassan

doi:10.5935/1676-2444.20210029

Abstract

ABSTRACT Hemoglobin A1c (HbA1c) measurement is commonly performed in diabetes mellitus patients to monitor glycemic control over the last three to four months. Carbamylated hemoglobin, which is the hemoglobin that binds to isocyanic acid derived from urea, is one of the possible analytical interference in the uremic patient. When measured by ion-exchange high-performance liquid chromatography (HPLC), carbamylated hemoglobin forms a peak that overlaps the peak of HbA1c, causing a falsely elevated HbA1c result. We report a case of a 60-years-old man who had a spurious increase in HbA1c, with a high carbamylated hemoglobin peak disproportionate to the urea value. Subsequent hemoglobin analysis using hemoglobin electrophoresis and HPLC hemoglobin testing system suggested hemoglobin J (Hb J) variant. Our case highlighted the possibility of misleading HbA1c interpretation in the presence of a high carbamylated hemoglobin peak, but not proportionate to urea value. In this study, Hb J was detected. A method free from hemoglobin variant interference should be used ideally, and monitoring glycemic control should be performed using alternative methods, such as serum fructosamine or continuous glucose monitoring.

Highlights

The history of muscle biopsy dates back to 1860, when Duchenne first performed a biopsy on a patient with symptoms of myopathy[1]
The twenty-first century has brought in a new spectacular progress in the utility of muscle biopsy with the commencement of molecular methods
The molecular era was made possible by the development of molecular biology and its application to muscle diseases

Summary

Introduction

The history of muscle biopsy dates back to 1860, when Duchenne first performed a biopsy on a patient with symptoms of myopathy[1]. The introduction of enzyme histochemical methods by Victor Dubowitz, in 1970, revolutionized the role of muscle biopsy in the diagnosis of various primary and secondary muscle diseases[2]. The adaptation of histo- and cytochemical techniques to the study of muscle biopsies improved diagnostic accuracy and enabled the identification of new changes and structures[3, 4].

Results

Conclusion