Pseudohypercreatininemia as an Initial Presentation of Waldenstrom’s Macroglobulinemia

Abstract

Chronic kidney disease (CKD) is a major public health problem. Estimated glomerular filtration rates based on serum creatinine values are used to diagnose this condition, and accuracy of laboratory testing is a crucial step in diagnosing and managing these patients efficiently in a timely manner. Spuriously elevated creatinine values have been reported due to the interference of other substances, including paraproteins. Paraproteins can interfere with the determination of various clinically important analytes in an unpredictable manner. While mild to moderate degrees of interference affecting the measurement of serum creatinine values have been previously reported, we present a case of a patient with markedly elevated serum creatinine who was referred for emergent assessment for possible consideration of renal replacement therapy. A thorough history and repeat laboratory investigations at several laboratories ultimately revealed the initial serum creatinine level to be spuriously high, i.e. "pseudohypercreatinimea" due to immunoglobulin interference. Further investigations ultimately led to the diagnosis of Waldenstrom's macroglobulinemia and the patient was appropriately treated. However, this case sheds light on the importance of being aware of a spuriously high creatinine value and its possible causes, as it can have significant diagnostic implications.