背景:在26%的犬慢性B细胞淋巴细胞白血病(B-CLL)病例中报告了高球蛋白血症。然而,少数病例通过蛋白质电泳和免疫固定(IF)进行表征,使用这些技术未知单克隆蛋白(M蛋白)的发生率。
目的:使用血浆蛋白电泳(PPE)表征和确定具有M蛋白的犬B-CLL病例的比例,常规和游离轻链(fLC)IF,并通过细胞管块(CTB)评估生产性B-CLL病例是否表达MUM1/IRF4。
方法:PPE,常规(靶向IgG,IgA,IgM,IgG4和轻链)和fLCIF使用来自通过外周血流式细胞术诊断的患者的48只狗B-CLL血浆样品进行。对15名患者的单独队列进行CTB。
结果:17/48例(35%)存在高蛋白血症(>7.5g/dL)。在32/48例(67%)中检测到M蛋白。其中,19/32例(59%)仅检测到完整的(单克隆重链和轻链)M蛋白,10/32例(31%)同时检测到完整和fLCM蛋白,3/32例(9%)仅检测到fLCM蛋白。IgM是检测到的最常见的克隆免疫球蛋白同种型(23例)。在具有可检测的M蛋白的情况下,CD21+细胞计数较高。等离子体fLCIF提示β-γ区干扰,可能是由凝血蛋白引起的。所有B-CLL病例一致表达PAX5,不表达MUM1/IRF4。
结论:大多数B-CLL病例具有M蛋白,而不是高蛋白血症。大多数副蛋白病例具有完整的IgM单克隆丙种球蛋白病;一个子集已记录了fLCs。应评估重度和fLC存在的预后意义。
BACKGROUND: Hyperglobulinemia is reported in 26% of canine chronic B-cell lymphocytic leukemia (B-CLL) cases. However, few cases have been characterized by protein electrophoresis and immunofixation (IF), and the incidence of a monoclonal protein (M-protein) is unknown using these techniques.
OBJECTIVE: To characterize and determine the proportion of canine B-CLL cases with an M-protein using plasma protein electrophoresis (PPE), routine and free light chain (fLC) IF, and to assess if productive B-CLL cases express MUM1/IRF4 by cell tube block (CTB).
METHODS: PPE, routine (targeting IgG, IgA, IgM, IgG4, and light chain) and fLC IF were performed using 48 dog B-CLL plasma samples from patients diagnosed via peripheral blood flow cytometry. CTB was performed on a separate cohort of 15 patients.
RESULTS: Hyperproteinemia (>7.5 g/dL) was present in 17/48 cases (35%). An M-protein was detected in 32/48 cases (67%). Of these, 19/32 cases (59%) had only complete (monoclonal heavy and light chain) M-proteins detected, 10/32 cases (31%) had both complete and fLC M-proteins detected, and 3/32 cases (9%) had only an fLC M-protein detected. IgM was the most common clonal immunoglobulin isotype detected (23 cases). CD21+ cell counts were higher in cases with detectable M-protein. Plasma fLC IF suggested β-γ region interference, likely caused by clotting proteins. All B-CLL cases consistently expressed PAX5 and did not express MUM1/IRF4.
CONCLUSIONS: Most B-CLL cases had an M-protein and were not hyperproteinemic. Most cases with paraproteins had a complete IgM monoclonal gammopathy; a subset had documented fLCs. The prognostic significance of heavy and fLC presence should be evaluated.