Mefire Kadija, El Mohtarim Ouissam, El Machtani Idrissi Samira, Bouhsain Sanae, Dami Abdellah, Biaz Asmaa
Biochemistry-Toxicology Laboratory, Faculty of Medicine and Pharmacy, Mohammed V Military Training Hospital, Mohammed V University, Rabat, MAR.
Cureus. 2025 Jul 22;17(7):e88517. doi: 10.7759/cureus.88517. eCollection 2025 Jul.
Serum protein electrophoresis (SPEP) typically reveals a single monoclonal (M) band in cases of monoclonal gammopathy (MG). Occasionally, two bands may appear, suggesting biclonal gammopathy. However, certain monoclonal immunoglobulins (Ig), particularly IgA, may exist in multiple polymerization states, mimicking biclonal patterns. We report the case of a patient with chronic renal failure referred for routine evaluation. SPEP revealed two monoclonal bands in the beta-2 and gamma-globulin regions, raising suspicion of biclonal gammopathy. Immunotyping (IT) identified both bands as IgA lambda, suggesting either biclonality or different polymerization states of the same monoclonal protein. To clarify, serum was treated with beta-mercaptoethanol. Post-reduction IT showed persistence of the beta-2-globulin band and disappearance of the gamma-globulin band, confirming a single IgA lambda monoclonal component with two distinct polymerization states. IgA MGs can exhibit atypical electrophoretic patterns due to variable polymerization, which may mimic biclonal patterns. In such scenarios, chemical reduction with beta-mercaptoethanol serves as a critical tool for accurate diagnosis.
在单克隆丙种球蛋白病（MG）病例中，血清蛋白电泳（SPEP）通常显示一条单克隆（M）带。偶尔会出现两条带，提示双克隆丙种球蛋白病。然而，某些单克隆免疫球蛋白（Ig），特别是IgA，可能以多种聚合状态存在，从而模拟双克隆模式。我们报告一例因进行常规评估而转诊的慢性肾衰竭患者。SPEP在β-2和γ球蛋白区域显示两条单克隆带，引发了对双克隆丙种球蛋白病的怀疑。免疫分型（IT）将两条带均鉴定为IgA λ，提示可能是双克隆性或同一单克隆蛋白的不同聚合状态。为明确诊断，用β-巯基乙醇处理血清。还原后IT显示β-2球蛋白带持续存在，γ球蛋白带消失，证实为具有两种不同聚合状态的单一IgA λ单克隆成分。由于聚合状态可变，IgA MG可表现出非典型电泳模式，这可能会模拟双克隆模式。在这种情况下，用β-巯基乙醇进行化学还原是准确诊断的关键工具。
