An autopsy case of anti-MDA5 antibody-positive amyopathic dermatomyositis with an initial manifestation of panniculitis on the left upper arm.

A 53-year-old man was presented with refractory panniculitis on the left upper arm that had persisted for 10 months. The patient was diagnosed with lupus profundus, wherein oral glucocorticoid therapy was initiated. Four months prior, ulceration was observed in the same area. Dapson was administered instead, scarring the ulcer but enlarging the panniculitis. Five weeks earlier, he developed a fever, productive cough, and dyspnoea. Three weeks earlier, a skin rash was observed on the forehead, left auricle posterior to the neck, and extensor aspect of the left elbow. Chest computed tomography showed pneumonia in the right lung, after which the patient's dyspnoea worsened. The patient was admitted and diagnosed with anti-MDA5 antibody-positive amyopathic dermatomyositis (ADM) based on skin findings, hyperferritinaemia, and rapidly progressive diffuse lung shadows. Glucocorticoid pulse therapy, intravenous cyclophosphamide, and tacrolimus were initiated, and later, plasma exchange therapy was combined. However, his condition worsened and required management with extracorporeal membrane oxygenation. The patient expired on day 28 after hospitalisation. An autopsy revealed hyalinising to fibrotic stages of diffuse alveolar damage. Strong expression of myxovirus resistance protein A was observed in three skin biopsy specimens from the time of initial onset, consistent with ADM. Anti-MDA5 antibody-positive ADM not only manifests typical cutaneous symptoms, but also rarely occurs with localised panniculitis, such as in the present case. In patients with panniculitis of unknown aetiology, the possibility of initial symptoms of ADM should be included in the differential diagnosis.

Thrombotic thrombocytopenic purpura that developed 3 years after systemic lupus erythematosus had remitted with rituximab therapy.

Patients with systemic lupus erythematosus (SLE) occasionally develop thrombotic thrombocytopenic purpura (TTP), which can be fatal. Here, we report a case of TTP developing 3 years after SLE remitted with rituximab (RTX) therapy. A 50-year-old woman was treated with RTX for marked immune thrombocytopenic purpura and autoimmune haemolytic anaemia due to SLE relapse. After induction of remission, she was treated with prednisolone alone without maintenance therapy with RTX. Approximately 3 years later, she was readmitted with marked thrombocytopenia and severe renal dysfunction. On admission, she was diagnosed with TTP for the first time based on severe reduction in a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS13) activity and detection of ADAMTS13 inhibitors. CD19+ B cells in the patient's serum increased to 34%, suggesting that B cells had reactivated once the effect of RTX had subsided. The patient was successfully treated with plasmapheresis, glucocorticoid pulse therapy, and RTX. There are no previous reports of newly diagnosed TTP with ADAMTS13 inhibitor production after having achieved remission of SLE with RTX. Therefore, our report also discusses the potential mechanisms of production of new autoantibodies after B-cell depletion therapy.

Effects of anti-SSA antibodies on the response to methotrexate in rheumatoid arthritis: A retrospective multicenter observational study.

Comparison of clinical response to methotrexate between anti-SSA antibody-positive and -negative patients with methotrexate-naïve rheumatoid arthritis and investigate the reasons for the differences in the response. For this multicenter retrospective cohort study, a total of 210 consecutive patients with rheumatoid arthritis who newly initiated methotrexate were recruited. The effects of anti-SSA antibody positivity on achieving a low disease activity according to the 28-joint Disease Activity Score based on C-reactive protein after 6 months of methotrexate administration were investigated using a logistic regression analysis. This study involved 32 and 178 anti-SSA antibody-positive and -negative patients, respectively. The rate of achieving low disease activity according to the 28-joint Disease Activity Score based on C-reactive protein at 6 months was significantly lower in the anti-SSA antibody-positive group than in the anti-SSA antibody-negative group (56.2% vs. 75.8%, P = 0.030). After 6 months, anti-SSA antibody-positive patients had significantly higher scores on the visual analogue scale (median [interquartile range]: 22 [15-41] vs. 19 [5-30], P = 0.038) and were frequently prescribed nonsteroidal anti-inflammatory drugs (37.5% vs. 18.0%, P = 0.018). In conclusion, the presence of anti-SSA antibodies might be a predictive factor for insufficient responses to treat-to-target strategy in rheumatoid arthritis. Residual pain might contribute to the reduced clinical response to methotrexate in anti-SSA antibody-positive patients with rheumatoid arthritis.

A Case of Granulomatosis with Polyangiitis with Various Breast Lesions as the Initial Symptoms: A Case-Based Review.

A 44-year-old woman presenting with pus-like discharge from the nipples visited our hospital for scleritis. Subcutaneous induration and ulceration were found on her breast. She was diagnosed with granulomatosis with polyangiitis (GPA) considering scleritis, sinusitis, cutaneous granuloma formation, and antiproteinase 3-antineutrophil cytoplasmic antibodies and was successfully treated with glucocorticoids. Fifteen months later, she developed pulmonary consolidation and a right breast nodule. Biopsies of the breast nodule showed granulomatous vasculitis, and she was treated with rituximab. While breast involvement in GPA is rare, unilateral breast mass is a typical clinical feature; thus, GPA should be considered in such cases.

A Case of Pulmonary Infarction Resembling Pneumonia during Immunosuppressive Treatment for Rheumatoid Arthritis.

A 67-year-old woman with rheumatoid arthritis (RA) presented with fever and dyspnea. Chest radiography and computed tomography (CT) revealed pulmonary infiltrates with ground-glass opacities. We considered bacterial or pneumocystis pneumonia because she was immunocompromised due to RA treatment. However, she had tachycardia and elevated D-dimer levels. We performed contrast-enhanced CT and subsequently diagnosed her with pulmonary embolism (PE). Though PE is not usually accompanied by parenchymal pulmonary shadows, pulmonary infarction may cause pulmonary infiltrates that can be mistaken for pneumonia. As RA is a thrombophilic disease, clinicians should be aware of PE and pneumonia as differential diagnoses in such patients.