Impaired redox status and cytochrome c oxidase deficiency in patients with polymyalgia rheumatica.
OBJECTIVE
To evaluate redox status and muscular mitochondrial abnormalities in patients with polymyalgia rheumatica (PMR).


METHODS
Prospective evaluation of deltoid muscle biopsy in 15 patients with PMR. Fifteen subjects matched for age and sex, with histologically normal muscle and without clinical evidence of myopathy, were used as controls. Cryostat sections of muscle were processed for conventional dyes, cytochrome c oxidase (COX), usual histochemical reactions, and Sudan black. A total of 300-800 fibres was examined in each case. Blood lactate, pyruvate, and lactate/pyruvate ratio were determined in all patients.


RESULTS
Ragged red fibres were found in eight patients with PMR and accounted for 0-0.5% of fibres. Focal COX deficiency was found in 14 (93%) of 15 patients and in nine (60%) of 15 controls. COX deficient fibres were more common in patients with PMR (range 0-2.5%; mean 0.9%) than in controls (range 0-1.2%; mean 0.3%) (paired t test, p=0.001). Seven (47%) of 15 patients had high blood lactate levels (1.50-2.60 mmol/l) or high blood lactate/pyruvate ratios (22-25).


CONCLUSIONS
PMR is associated with mitochondrial abnormalities not solely related to the aging process.
Chariot
P
P
Department of Pathology (Neuromuscular Disorders), Hôpital Henri-Mondor, 94000 Créteil, France. pchariot@cybercable.fr
Chevalier
X
X
Yerroum
M
M
Drogou
I
I
Authier
F J
FJ
Gherardi
R
R
D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D016022:Case-Control Studies; D030401:Cytochrome-c Oxidase Deficiency; D005260:Female; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D008875:Middle Aged; D018656:Muscle Fibers, Fast-Twitch / Q000473:pathology; D018482:Muscle, Skeletal / Q000378:metabolism / Q000473:pathology; D010084:Oxidation-Reduction; D011111:Polymyalgia Rheumatica / Q000378:metabolism* / Q000473:pathology; D011446:Prospective Studies; D019289:Pyruvic Acid / Q000097:blood; D018709:Statistics, Nonparametric; D013385:Succinate Dehydrogenase / Q000032:analysis
D019344:Lactic Acid; D019289:Pyruvic Acid; D013385:Succinate Dehydrogenase