Perfetti V, Colli Vignarelli M, Anesi E, Garini P, Quaglini S, Ascari E, Merlini G
Biotechnology and Organ Transplantation Research Laboratories, University of Pavia, IRCCS Policlinico S. Matteo, Pavia, Italy.
Haematologica. 1999 Mar;84(3):218-21.
Primary amyloidosis is a lethal form of plasma cell (PC) dyscrasia characterized by deposits of monoclonal immunoglobulin light chains that cause organ dysfunction. In contrast to multiple myeloma, the amyloid clone is typically indolent and of small size, and marrow PC clonality is not always apparent. This is generally investigated by analyzing the light chain isotype ratio in bone marrow PC. We investigated whether the degree of PC infiltration (PC%) and clonality (PC isotype ratio) affected survival in 56 consecutive patients with primary amyloidosis.
PC% was determined by morphologic examination. Immunofluorescence microscopy was used to determine the PC light chain isotype ratio. Statistical analysis was carried out using Cox regression models.
The degrees of PC clonality and infiltration were inversely correlated with survival (PC isotype ratio, p = 0.001; PC%, p = 0.008). The two variables were weakly correlated (p = 0.02; r = 0.3). Bone marrow PC isotype ratio demonstrated a powerful independent prognostic value at multivariate analysis when analyzed together with congestive heart failure (the major known negative prognostic factor) and PC%. k/l ratio cut-off values of 0.2 (l patients, p = 0.022) and 16 (k patients, p = 0.03) discriminated two groups with a similar number of patients and significantly different survivals.
PC clonality and marrow infiltration are important parameters that influence prognosis, presumably because they reflect the amount of pathogenic light chain synthesis.
原发性淀粉样变性是浆细胞发育异常的一种致死形式，其特征为单克隆免疫球蛋白轻链沉积导致器官功能障碍。与多发性骨髓瘤不同，淀粉样克隆通常进展缓慢且规模较小，骨髓浆细胞克隆性并不总是很明显。这通常通过分析骨髓浆细胞中的轻链同种型比例来研究。我们调查了56例连续的原发性淀粉样变性患者中浆细胞浸润程度（浆细胞百分比）和克隆性（浆细胞同种型比例）是否影响生存。
通过形态学检查确定浆细胞百分比。采用免疫荧光显微镜确定浆细胞轻链同种型比例。使用Cox回归模型进行统计分析。
浆细胞克隆性和浸润程度与生存呈负相关（浆细胞同种型比例，p = 0.001；浆细胞百分比，p = 0.008）。这两个变量呈弱相关（p = 0.02；r = 0.3）。在多变量分析中，当与充血性心力衰竭（主要已知的不良预后因素）和浆细胞百分比一起分析时，骨髓浆细胞同种型比例显示出强大的独立预后价值。κ/λ比例截断值为0.2（λ型患者，p = 0.022）和16（κ型患者，p = 0.03）区分出两组患者数量相似但生存明显不同的患者。
浆细胞克隆性和骨髓浸润是影响预后的重要参数，可能是因为它们反映了致病性轻链合成的量。
