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. 2012:6:54-63.
doi: 10.2174/1874312901206010054. Epub 2012 Jun 1.

Laboratory Test Abnormalities are Common in Polymyositis and Dermatomyositis and Differ Among Clinical and Demographic Groups

Rita Volochayev  1 , Gyorgy Csako, Robert Wesley, Lisa G Rider, Frederick W Miller
Affiliations

Laboratory Test Abnormalities are Common in Polymyositis and Dermatomyositis and Differ Among Clinical and Demographic Groups

Rita Volochayev et al. Open Rheumatol J. 2012.

Abstract

Objective: 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.

Methods: 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.

Results: 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.

Conclusion: 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.

Keywords: Myositis; laboratory testing.; phenotypes.

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Figures

Fig. (1)
Fig. (1)
Box plots showing the median, 25th and 75th percentiles and highest and lowest values for CK, CK-MB and aldolase in all myositis patients and differences among groups. The shaded area depicts the normal range.* *Abbreviations: Dx, diagnosis; DM, dermatomyositis; PM, polymyositis; B, black; W, white, Caucasian; O, other; rest per Table 1.
Fig. (2)
Fig. (2)
Box plots showing the median, 25th and 75th percentiles and highest and lowest values for AST, ALT and LD in all myositis patients and differences among groups. The shaded area depicts the normal range*. *Abbreviations: per Table 1 and Fig. (1).
Fig. (3)
Fig. (3)
Box plots showing the median, 25th and 75th percentiles and highest and lowest values for WBC count, lymphocytes and ESR in all myositis patients and differences among groups. The shaded area depicts the normal range*. *Abbreviations: per Table 1 and Fig. (1).
Fig. (4)
Fig. (4)
Scatterplots and the 99% and 95% prediction intervals for the relationships among CK and aldolase (A), ALT (B), AST (C) and LD (D) levels*. *Abbreviations as in Table 1 and Figs. (1-3).
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References

    1. Miller FW. Inflammatory Myopathies: Polymyositis, dermatomyositis, and related conditions. In: Koopman W, Moreland L, editors. Arthritis and Allied Conditions. Philadelphia: Williams and Wilkins; 2005. pp. 1593–620. A Textbook of Rheumatology.
    1. Rider LG, Miller FW. Deciphering the clinical presentations, pathogenesis, and treatment of the idiopathic inflammatory myopathies. J Am Med Assoc. 2011;305(2):183–90. - PMC - PubMed
    1. Mastaglia FL, Garlepp MJ, Phillips BA, Zilko PJ. Inflammatory myopathies: clinical, diagnostic and therapeutic aspects. Muscle Nerve. 2003;27(4):407–25. - PubMed
    1. Munsat TL, Baloh R, Pearson CM, Fowler WJ. Serum enzyme alterations in neuromuscular disorders. J Am Med Assoc. 1973; 226:1536–43. - PubMed
    1. Rider LG, Miller FW. Laboratory evaluation of the inflammatory myopathies. Clin Diagn Lab Immunol. 1995;2(1):1–9. - PMC - PubMed

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