Enhanced expression of myeloid-related protein complex (MRP8/14) in macrophages and multinucleated giant cells in granulomas of patients with active cardiac sarcoidosis.
BACKGROUND
The myeloid-related protein complex (MRP8/14) is expressed in activated human macrophages and reported to be involved in the inflammatory process. The expression of MRP8/14 in patients with cardiac sarcoidosis and idiopathic dilated cardiomyopathy (DCM) was investigated.


RESULTS
Serum MRP8/14 levels were measured in 35 patients with sarcoidosis and 23 patients with DCM. Sera from 30 normal volunteers served as controls. Additionally, the expression profiles of MRP8/14 in the myocardium from 12 patients with active cardiac sarcoidosis and 10 DCM patients were examined immunohistochemically. Serum MRP8/14 levels were significantly higher in patients with sarcoidosis than in normal controls [515+/-549 (SD) ng/ml vs 230+/-115 ng/ml, p=0.0019]. In the sarcoidosis group, serum MRP8/14 levels in patients with definite cardiac involvement (n=10) were significantly higher than in those without (n=25) (974+/-878 ng/ml vs 332+/-204 ng/ml, p=0.0227) and they were also higher than in DCM patients (vs 252+/-108 ng/ml, p=0.0026). Immunohistochemically, MRP8/14 was specifically positive in the cytoplasm of macrophages and multinucleated giant cells in the myocardial granulomas.


CONCLUSIONS
MRP8/14 may be involved in the pathogenesis of sarcoid granulomas. The measurement of serum MRP8/14 levels is useful for the diagnosis of sarcoidosis, and their higher levels suggest the cardiac involvement.
Terasaki
Fumio
F
Department of Internal Medicine III, Osaka Medical College, 2-7 Daigaku-machi, Takatsuki 569-8686, Japan. in3012@poh.osaka-med.ac.jp
Fujita
Masatoshi
M
Shimomura
Hiroaki
H
Tsukada
Bin
B
Otsuka
Koji
K
Otsuka
Kaoru
K
Katashima
Takashi
T
Ikemoto
Masaki
M
Kitaura
Yasushi
Y
D000328:Adult; D000368:Aged; D040501:Calgranulin A / Q000378:metabolism*; D040502:Calgranulin B / Q000378:metabolism*; D002311:Cardiomyopathy, Dilated / Q000378:metabolism / Q000473:pathology; D016022:Case-Control Studies; D005260:Female; D015726:Giant Cells / Q000378:metabolism* / Q000473:pathology; D006101:Granuloma, Giant Cell / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D008264:Macrophages / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism / Q000473:pathology; D012507:Sarcoidosis / Q000378:metabolism* / Q000473:pathology
D040501:Calgranulin A; D040502:Calgranulin B