Volochayev Rita, Csako Gyorgy, Wesley Robert, Rider Lisa G, Miller Frederick W
Environmental Autoimmunity Group, Program of Clinical Research, National Institute of Environmental Health Sciences, National Institutes of Health, HHS, Bethesda, Maryland, USA.
Open Rheumatol J. 2012;6:54-63. doi: 10.2174/1874312901206010054. Epub 2012 Jun 1.
Given the difficulties regarding the interpretation of common laboratory test results in polymyositis (PM) and dermatomyositis (DM) in clinical practice, we assessed their range of abnormalities, differences among phenotypes and interrelationships in a large referral population.
We retrospectively assessed 20 commonly measured blood laboratory tests in 620 well-defined PM/DM patients at different stages of illness and treatment to determine the frequency, range of abnormalities and correlations among clinical, gender, racial and age phenotypes.
Myositis patients at various stages of their disease showed frequent elevations of the serum activities of creatine kinase (51%), alanine aminotransferase (43%), aspartate aminotransferase (51%), lactate dehydrogenase (60%), aldolase (65%) and myoglobin levels (48%) as expected. Other frequent abnormalities, however, included elevated high white blood cell counts (36%), low lymphocyte counts (37%), low hematocrit levels (29%), low albumin levels (22%), high creatine kinase MB isoenzyme fractions (52%), high erythrocyte sedimentation rates (33%) and high IgM and IgG levels (16% and 18%, respectively). Many of these tests significantly differed among the clinical, gender, racial and age groups. Significant correlations were also found among a number of these laboratory tests, particularly in the serum activity levels of creatine kinase, the transaminases, lactate dehydrogenase and aldolase.
Laboratory test abnormalities are common in PM/DM. Knowledge of the range of these expected abnormalities in different myositis phenotypes, gender and age groups and their correlations should assist clinicians in better interpretation of these test results, allow for a clearer understanding what level of abnormality warrants further evaluation for liver or other diseases, and may avoid unnecessary laboratory or other testing.
鉴于临床实践中在解读多发性肌炎（PM）和皮肌炎（DM）常见实验室检查结果时存在困难，我们在一个大型转诊人群中评估了这些检查结果的异常范围、不同表型之间的差异以及相互关系。
我们回顾性评估了620例明确诊断为PM/DM且处于疾病和治疗不同阶段患者的20项常用血液实验室检查，以确定临床、性别、种族和年龄表型的异常频率、范围以及相关性。
正如预期的那样，处于疾病各阶段的肌炎患者血清肌酸激酶（51%）、丙氨酸氨基转移酶（43%）、天冬氨酸氨基转移酶（51%）、乳酸脱氢酶（60%）、醛缩酶（65%）活性及肌红蛋白水平（48%）经常升高。然而，其他常见异常包括白细胞计数升高（36%）、淋巴细胞计数降低（37%）、血细胞比容水平降低（29%）、白蛋白水平降低（22%）、肌酸激酶MB同工酶分数升高（52%）、红细胞沉降率升高（33%）以及IgM和IgG水平升高（分别为16%和18%）。其中许多检查在临床、性别、种族和年龄组之间存在显著差异。在这些实验室检查中还发现了许多显著的相关性，特别是在肌酸激酶、转氨酶、乳酸脱氢酶和醛缩酶的血清活性水平之间。
实验室检查异常在PM/DM中很常见。了解不同肌炎表型、性别和年龄组中这些预期异常的范围及其相关性应有助于临床医生更好地解读这些检查结果，更清楚地了解何种异常程度需要进一步评估肝脏或其他疾病，并可能避免不必要的实验室或其他检查。
