A multianalyte assay panel with cell-bound complement activation products demonstrates clinical utility in systemic lupus erythematosus.

OBJECTIVE: To evaluate the clinical utility of the multianalyte assay panel (MAP), commercially known as AVISE Lupus test (Exagen Inc.), in patients suspected of SLE. METHODS: A systematic review of medical records of ANA-positive patients with a positive (>0.1) or negative (<-0.1) MAP score was conducted when the MAP was ordered (T0), when the test results were reviewed (T1) and at a later time (T2, ≥8 months after T1). Confidence in the diagnosis of SLE and initiation of hydroxychloroquine (HCQ) were assessed. RESULTS: A total of 161 patient records from 12 centres were reviewed at T0 and T1. T2 occurred for 90 patients. At T0, low, moderate and high confidence in SLE diagnosis was reported for 58%, 30% and 12% patients, respectively. Confidence in SLE diagnosis increased for the MAP positive, while MAP negative made SLE less likely. Odds of higher confidence in SLE diagnosis increased by 1.74-fold for every unit of increase of the MAP score (p<0.001). Using the MAP-negative/anti-double-stranded DNA-negative patients as reference, the HR of assigning an International Classification of Diseases, Tenth Revision lupus code was 7.02-fold, 11.2-fold and 14.8-fold higher in the low tier-2, high tier-2 and tier-1 positive, respectively (p<0.001). The HR of initiating HCQ therapy after T0 was 2.90-fold, 4.22-fold and 3.98-fold higher, respectively (p<0.001). CONCLUSION: The MAP helps increase the confidence in ruling-in and ruling-out SLE in patients suspected of the disease and informs on appropriate treatment decisions.

Neutrophilic myositis: an extra-intestinal manifestation of ulcerative colitis.

Myositis of the skeletal muscle is rarely seen as an extraintestinal manifestation of inflammatory bowel disease. We report a case of a 36-year-old man with ulcerative colitis who developed 3 episodes of steroid responsive myositis in a 4-month period. He presented with a blistering rash followed by pain and massive swelling in the right shoulder and lower extremities, with marked elevation in muscle enzymes. Diagnosis of myositis was made after a muscle biopsy, which showed neutrophilic infiltrate in the deep subcutaneous tissue and skeletal muscle. Review of the literature indicates only a few cases of myositis associated with ulcerative colitis, most of them during an acute exacerbation of the disease. However, the present patient had his first episode when the ulcerative colitis was in remission. Myositis in ulcerative colitis may present atypically, in particular mimicking pyomyositis. Clinicians should be aware of this unusual steroid-sensitive complication.