Cohen H J, Crawford J, Rao M K, Pieper C F, Currie M S
Department of Medicine and Comprehensive Cancer Center, Duke University Medical Center, Durham, North Carolina 27710, USA.
Am J Med. 1998 May;104(5):439-44. doi: 10.1016/s0002-9343(98)00080-1.
To determine if there is an increased prevalence of monoclonal gammopathy in elderly blacks compared with whites, analogous to the difference in incidence of multiple myeloma reported for the two racial groups and to confirm age and gender relationships.
Subjects were from the Duke Established Populations for the Epidemiologic Study of the Elderly, selected on the basis of stratified random household sampling. Blacks were oversampled to allow for increased statistical precision in racial comparisons. In all, 1,732 subjects (aged > 70 years) consented to blood drawing and constitute the sample for this study. Monoclonal immunoglobulins were determined by agarose gel electrophoresis and immunofixation.
One hundred six subjects (6.1%) had a monoclonal gammopathy. There was a greater than twofold difference in prevalence between blacks (8.4%) and whites (3.8%) (P < 0.001); monoclonal gammopathy prevalence increased with age, and was greater in men than women. Those with monoclonal gammopathy did not differ from those without in socioeconomic status, urban/rural residence, or education. The presence of monoclonal gammopathy was not associated with any specific diseases nor with impaired functional status. There was a slight increase in serum creatinine levels and decrease in hemoglobin and albumin levels in patients with monoclonal gammopathy, but no difference in interleukin-6 (IL-6) levels. Moreover, IL-6 levels were not correlated significantly with the level of monoclonal protein.
Prevalence of monoclonal gammopathy is significantly greater among blacks than whites in a community-based sample, in approximately the same ratio that multiple myeloma has been reported in the two groups. Given the absence of correlation with environmental factors, there may be a biological racial difference in susceptibility to an early event in the carcinogenic process leading to multiple myeloma.
确定老年黑人与白人相比单克隆丙种球蛋白病的患病率是否增加，这类似于报道的两个种族群体多发性骨髓瘤发病率的差异，并确认年龄和性别关系。
研究对象来自杜克老年人流行病学研究的既定人群，通过分层随机家庭抽样选取。对黑人进行了过度抽样，以便在种族比较中提高统计精度。共有1732名受试者（年龄>70岁）同意抽血，构成本研究的样本。通过琼脂糖凝胶电泳和免疫固定法测定单克隆免疫球蛋白。
106名受试者（6.1%）患有单克隆丙种球蛋白病。黑人（8.4%）和白人（3.8%）的患病率差异超过两倍（P<0.001）；单克隆丙种球蛋白病的患病率随年龄增加，男性高于女性。患有单克隆丙种球蛋白病的人与未患该病的人在社会经济地位、城乡居住或教育方面没有差异。单克隆丙种球蛋白病的存在与任何特定疾病或功能状态受损均无关联。单克隆丙种球蛋白病患者的血清肌酐水平略有升高，血红蛋白和白蛋白水平略有下降，但白细胞介素-6（IL-6）水平无差异。此外，IL-6水平与单克隆蛋白水平无显著相关性。
在基于社区的样本中，黑人中单克隆丙种球蛋白病的患病率显著高于白人，其比例与两组中报道的多发性骨髓瘤的比例大致相同。鉴于与环境因素无关，在导致多发性骨髓瘤的致癌过程中，早期事件的易感性可能存在生物学上的种族差异。
