Session Information
Session Type: ACR Poster Session C
Session Time: 9:00AM-11:00AM
Background/Purpose: Systemic vasculitis comprises a group of diseases characterized by non-infectious inflammation of vessels in various organs. Histopathological confirmation of systemic vasculitis is required for the diagnosis; a biopsy is usually performed in clinically suspect organs, such as the skin, peripheral nerves and kidneys. The biopsy of an involved organ is invasive and carries the risk of complications. By contrast, gastrocnemius muscle biopsy is simple and minimally invasive technique that may be performed by a rheumatologist.
Methods: Retrospective study (1984-2015) Center: tertiary academic hospital, referral area 850.000 inhabitants. We analyzed the database of all muscular biopsies performed at our hospital. We selected all patients undergoing a gastrocnemius biopsy for possible diagnosis of systemic vasculitis, we analyzed the clinical, laboratory, neurophysiological and pathologic data. Biopsies were classified as positive or negative for vasculitis. A positive muscular biopsy was defined by the presence of necrotizing vasculitis or non necrotizing vasculitis seen by optical microscopy. Muscular biopsy was performed in all cases at the medial gastrocnemius muscle by a rheumatologist; all these biopsies were “open” and unilateral. The diagnosis of systemic vasculitis was based on clinical, serological and histological data.
Results: 619 muscular biopsies were performed, 55 were indicated with suspicion of systemic vasculitis, 29 (52.7%) female and 26 male (47.3%), median age 64.4 years (DS 15.22). Of the 55 muscular biopsies, 47 (85.4%) were positive (sensitivity of 85%) and 8 (14.6%) were negative. The final diagnosis was: 41 (74.5%) necrotizing vasculitis (microscopic polyangiitis and polyarteritis nodosa), 5 (9.1%) eosinophilic granulomatosis with polyangiitis, 4 (7.3%) granulomatosis with polyangiitis, 2 (3.6%) mixed cryoglobulinemia, 1 (1.8%) rheumatoid arthritis-associated vasculitis and 2 (3.6%) none diagnosed. Of 45 patients, 24 (53.3%) were ANCA-associated: 20 patients had positive biopsy and 4 negative biopsy. No significant differences were observed between the two groups in any of the assessment categories except in the electomiographic pattern. The positive biopsy group showed electromiographic alterations (p=0.01)Furthermore, the positive biopsy group showed more frequently systemic manifestations such as: weight loss, myalgia, paresthesias, purpura and testicular pain. These differences were not statistically significant. No complications were encountered in the procedure.
Conclusion: Muscle biopsy is a simple, clinically useful, safe and minimally invasive procedure for the diagnosis of vasculitis with high sensitivity. No significant differences were observed in clinical or analytical features between patients with positive or negative biopsy, except in electromyography patients with positive biopsy had more a frequent pathological pattern.
| Biopsy-positive (n = 47) | Biopsy-negative (n = 8) | p-value | ||
| male/female, n (%) | 24/23 (51/49) | 5/3 (62,5/37,5) | 0.5 | |
| age at biopsy (years), mean (sd) | 65,1 (14,34) | 60 (20,2) | 0.3 | |
| ANCA positive/ negative |
|
4(50)/4(50) | 0.8 | |
| serum ESR (mm), mean (sd) | 58,2 (35,6) | 64,7 (36,3) | 0.6 | |
| hemoglobine (g/dL), mean (sd) | 11,24 (1,4) | 10,25 (1,3) | 0.8 | |
| weight loss (≥ 2 kg) n (%) | 13 (27,7) | 2 (25) | 0.8 | |
| fever (≥ 38 °C) n (%) | 20 (42,5) | 5 (62,5) | 0.3 | |
| myalgia n (%) | 18 (38,3) | 3 (37,5) | 0.9 | |
| paresthesias n (%) | 20 (42,6) | 2 (25) | 0.3 | |
| arthralgia n (%) | 12 (25,5) | 2 (25) | 0.9 | |
| purpura n (%) | 7 (14,9) | 1 (12,5) | 0.8 | |
| testicular pain n (%) | 3 (6,4) | 0 | 0.4 | |
| legs ulcers n (%) | 5 (10,6) | 2 (25) | 0.3 | |
| abdominal pain n (%) | 3 (6,4) | 1 (12,5) | 0.5 | |
| calf pain n (%) | 12 (25,5) | 3 (37,5) | 0.5 | |
| patologic electromiography | 36 (76,6) | 2 (25) | 0.01 |
To cite this abstract in AMA style:
Rodriguez-Muguruza S, Sanint J, Saenz-Sarda X, Prior A, Garcia Y, Mateo ML, Holgado S, Cañellas J, Martínez-Morillo M, Tena X, Olivé A. Use of Muscle Biopsies for the Diagnosis of Systemic Vasculitis in a Rheumatology Service [abstract]. Arthritis Rheumatol. 2016; 68 (suppl 10). https://acrabstracts.org/abstract/use-of-muscle-biopsies-for-the-diagnosis-of-systemic-vasculitis-in-a-rheumatology-service/. Accessed .« Back to 2016 ACR/ARHP Annual Meeting
ACR Meeting Abstracts - https://acrabstracts.org/abstract/use-of-muscle-biopsies-for-the-diagnosis-of-systemic-vasculitis-in-a-rheumatology-service/