Clinicopathologic features of sporadic inclusion body myositis in China

Abstract

This study is to investigate the clinical and pathologic features of sporadic inclusion body myositis (sIBM) in China. We retrospectively evaluated the clinical and pathological features of consecutive patients in our department between January 1986 to May 2012. Total 28 cases of sIBM (20 males, 8 females, mean age was 56.93±8.79) were obtained by review of all 4099 muscle biopsy reports. The proportion of sIBM was 0.68% (28/4099) in China. Muscle weakness of quadriceps appeared 100% in 28 cases, while conspicuous atrophy of quadriceps appeared only in five cases (17.86%). Creatase values of 28 patients with sIBM were normal or mildly elevated. Muscle biopsies showed that atrophic fibers resembled more frequent in small angular and irregular shape (82.14%), less common in small round shape (17.86%). Rimmed vacuoles resembled crack (67.86%) and round (32.14%) shape. Mononuclear cell invasion into necrotic muscle fibers (35.71%) was more frequent than non-necrotic muscle fibers (7.14%). sIBM was still a rare disease in China compared to other countries. There were some certain specific pathological characteristics existed in Chinese sIBM patients.

Immunohistochemical and ultrastructural analysis of sporadic inclusion body myositis: a case series

“…In most cases we saw myofiber atrophy with subsequent invasion of connective and adipose tissue. The results are in accordance with observations made by others [12,17,27,36,37]. In a few cases hypertrophic myofibers in IBM patients were also reported [12,27].…”

“…Since s-IBM is an untreatable disease establishing the final diagnosis is critical for patients in order to avoid an ineffective immunosuppressive therapy with its many side effects [9,15], and to start physiotherapy [33]. In our study the clinical features, including weakness of upper and lower extremities, difficulty in climbing stairs as well as patients' ages were typical and similar to other reports [12,27,34]. Moreover, similarly to Hermanns et al [4] and Sakai et al [17] we observed periodical increases in the levels of CK and LDH enzymes in the studied patients' serum.…”

“…We found that skeletal muscle biopsies of IBM patients presented typical changes which have been well described by others, including hypertrophy of connective and adipose tissues, focal occurrence of necrotic fibers, RVs, a pattern of inflammatory cell infiltrations or pathological protein aggregates [3,4,9,12,17,37]. In most cases we saw myofiber atrophy with subsequent invasion of connective and adipose tissue.…”

“…Moreover, similarly to Hermanns et al [4] and Sakai et al [17] we observed periodical increases in the levels of CK and LDH enzymes in the studied patients' serum. In patients from a study conducted in China the average value of CK was 397.38 IU/L, whereas for LDH it was 218.21 IU/L [12]. In our study, the average values of CK and LDH were much higher, 1068 IU/L and 344 IU/L, respectively.…”

“…However, many scientists feel that it is a primary degenerative disorder that triggers inflammation [10,11]. It is a progressive disease and is the most common disease of skeletal muscle in patients over the age of 50 [6,12], leading to serious disability [3,7,13]. The onset of symptoms in patients younger than 60 years of age is typical for 18-20% of patients [6].…”