Modern rheumatology case reports最新文献

Thrombotic microangiopathy (TMA) is a rare but life-threatening complication in idiopathic inflammatory myopathies. Although TMA has been increasingly recognised in anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis, it remains exceptionally uncommon in anti-signal recognition particle (SRP) antibody-positive immune-mediated necrotising myopathy (IMNM). We describe a 62-year-old woman with anti-SRP antibody-positive IMNM who developed rapidly progressive TMA shortly after the initiation of immunosuppressive therapy, including tacrolimus. At presentation, she exhibited early proteinuria, severe myositis activity, and markedly elevated creatine kinase levels. Despite prompt high-dose corticosteroids, rapid withdrawal of tacrolimus, plasma exchange, intravenous immunoglobulin, and rituximab, her TMA progressed to dialysis-dependent acute kidney failure, although she ultimately survived and was successfully weaned from mechanical ventilation. To our knowledge, this represents only the second reported case of TMA associated with anti-signal recognition particle antibody-positive IMNM. Patients with highly active IMNM and early renal involvement may be particularly vulnerable to calcineurin inhibitor-associated TMA, and clinicians should exercise caution when introducing these agents in such settings. Early recognition of proteinuria, thrombocytopenia, and laboratory features of hemolysis may facilitate a timely diagnosis and guide appropriate therapeutic intervention.

A 61-year-old Japanese woman with a 20-year history of rheumatoid arthritis (RA) had been treated with various antirheumatic drugs, including biologics and Janus kinase inhibitors. Subcutaneous methotrexate (MTX) was added to sarilumab, resulting in improvement in her joint tenderness. Six months later, however, while continuing both agents, she developed exertional dyspnea. Computed tomography revealed bilateral ground-glass opacities, and transbronchial lung cryobiopsy (TBLC) showed pathological findings consistent with MTX-induced pneumonitis. She responded rapidly to glucocorticoids, but subsequently developed recurrent episodes of RA-associated organizing pneumonia despite discontinuation of MTX, which was evaluated by repeat bronchoscopy and supported the diagnosis of RA-associated organizing pneumonia, and prolonged glucocorticoid therapy was required. MTX-induced pneumonitis is a potentially life-threatening complication. This case demonstrates that subcutaneous MTX does not eliminate the risk of pneumonitis, that transbronchial lung cryobiopsy is a valuable diagnostic tool allowing clear pathological characterization with ample tissue to support confident pathologic diagnosis, and that the marked discrepancy in imaging supports that repeat bronchoscopy is warranted rather than avoided when new imaging points to an alternative diagnosis.

Polyarteritis nodosa (PAN) is a systemic necrotising vasculitis of medium-sized arteries, often challenging to differentiate from other autoimmune and thrombotic disorders due to overlapping clinical features. This case-based literature review describes a 56-year-old male with a prior diagnosis of catastrophic antiphospholipid syndrome who presented with digital ischemia, myalgias, and a progressive cutaneous rash. Despite initial treatment with anticoagulation, symptoms persisted, and a skin biopsy ultimately revealed medium-vessel vasculitis consistent with PAN. Muscle biopsy was inconclusive, underscoring the difficulty of diagnosis in the setting of coexisting vasculopathies. This case illustrates the diagnostic complexity at the intersection of inflammatory and thrombotic syndromes and highlights the potential for concurrent or misclassified disease. A review of literature reveals rare but documented associations between PAN and antiphospholipid syndrome, yet no diagnostic tool for differentiation exists. Early recognition and accurate differentiation are critical to optimise outcomes in such overlapping syndromes. Future studies should evaluate a possible differentiation score or explore further diagnostics to help differentiate these inflammatory and thrombotic syndromes to better recognise and treat these conditions.

A 43-year-old man reported with upper respiratory tract symptoms and tested positive for coronavirus disease 2019 (COVID-19) antigens. The symptoms improved quickly, but 1 month later, myalgia in both shoulders and from both thighs to both lower legs, pharyngeal pain, and dyspnoea appeared. His muscle strength was low, and laboratory tests showed an elevated serum creatine kinase level at 1273 U/l. A COVID-19 polymerase chain reaction test was positive on the day of admission, and a diagnosis of multisystem inflammatory syndrome in adults was considered. The patient received high-dose intravenous immunoglobulin (30 g for 5 days) for myositis due to multisystem inflammatory syndrome in adults with muscle weakness refractory to glucocorticoids, but progressive dysphagia led to a gradual reduction in the ability to swallow saliva. The patient choked due to sputum, resulting in cardiopulmonary arrest on Day 31. Lifesaving measures were immediately performed, and the patient's heartbeat resumed. However, on Day 39, the patient experienced a gastrointestinal perforation and underwent emergency surgery. Since antinuclear matrix protein 2 antibody-positive dermatomyositis (DM) is known as a severe form of DM that can cause gastrointestinal perforation, we measured the antibody and found it to be positive. We report the case of gastrointestinal perforation in a patient with antinuclear matrix protein 2 antibody-positive DM that developed after a COVID-19 infection and was successfully managed through multidisciplinary therapy.

Idiopathic multicentric Castleman's disease (iMCD) is a systemic lymphoproliferative disorder characterised by interleukin (IL)-6 overproduction. To date, several cases of iMCD with autoimmune features have been reported, and cases of iMCD complicated by IgA vasculitis have also been reported. IL-6 is reported to promote the production of galactose-deficient IgA1, a key pathogenic factor in IgA vasculitis. Therefore, IL-6 overproduction in iMCD may contribute to the development of IgA vasculitis in these cases. Here, we present two cases of iMCD complicated by IgA vasculitis, both successfully treated with tocilizumab, an IL-6 receptor blockade. Furthermore, our literature review identified two reported cases of iMCD complicated by IgA nephropathy, and one case of iMCD complicated by IgA vasculitis, all of which responded favourably to tocilizumab. Our cases and literature review suggest the pathogenic role of IL-6 in the development of IgA vasculitis in iMCD and the effectiveness of tocilizumab as a potential therapeutic option not only for iMCD itself, but also for IgA vasculitis in the setting of iMCD.

Systemic lupus erythematosus-associated thrombotic thrombocytopenic purpura is a rare but potentially life-threatening condition that is characterised by thrombocytopenia, microangiopathic haemolytic anaemia, and multiorgan involvement. Here, we describe a refractory case of systemic lupus erythematosus-associated thrombotic thrombocytopenic purpura in a 38-year-old Japanese woman who was unresponsive to plasma exchange and glucocorticoid therapy. Combination treatment with caplacizumab and rituximab leads to rapid platelet recovery, resolution of neurological symptoms, and sustained remission. Caplacizumab provided immediate inhibition of microthrombus formation, whereas rituximab targeted the underlying autoimmune process through B cell depletion. Following treatment, ADAMTS13 activity normalised, allowing for corticosteroid tapering and the maintenance of long-term remission. This case highlights the value of early combination therapy for refractory systemic lupus erythematosus-associated thrombotic thrombocytopenic purpura, and it suggests that early combination therapy with caplacizumab and rituximab may act synergistically to improve outcomes.

Rheumatoid vasculitis (RV) is an extra-articular complication characterised by small-to-medium vessel vasculitis associated with rheumatoid arthritis, leading to various organ involvements. However, there are few reports of RV associated with aneurysms causing intra-abdominal haemorrhage. Although the incidence of RV has recently decreased, its prognosis remains poor. We herein report a case of RV in a patient with a 1.5-year history of treatment for late-onset rheumatoid arthritis. The patient died of intrahepatic haemorrhage caused by the rupture of a hepatic artery aneurysm. RV can be challenging to diagnose clinically and is sometimes only identified at autopsy. When inflammatory findings arise that do not correspond to the activity of arthritis, careful differential diagnosis is essential.

Scurvy, a disease caused by vitamin C deficiency, is now uncommon in developed countries with ample food resources. We present the case of a 28-year-old man with no significant past medical history who presented with lower extremity petechiae, initially raising suspicion for vasculitis. Although his skin biopsy findings were consistent with vasculitis, based on the characteristic perifollicular distribution of the purpura, the presence of corkscrew hairs, and the finding of a subfascial haematoma of the gastrocnemius muscle, which raised suspicion for a bleeding tendency, led us to suspect scurvy. A detailed dietary history revealed that he had consumed an imbalanced diet with no intake of fresh fruits or vegetables for more than 6 months. Serum ascorbic acid concentration was measured to be < 0.2 μg/ml, confirming the diagnosis of scurvy. In conclusion, scurvy can occur even in healthy young individuals without prior medical history living in developed countries and can present to rheumatologists as a mimic of vasculitis. It should be considered in the differential diagnosis of vasculitis, and a detailed dietary history should be obtained when suspected.

Although other iatrogenic immunodeficiency-associated lymphoproliferative disorders (OIIA-LPDs) are rare, they are important adverse effects of immunosuppressive therapies. Even though anti-melanoma differentiation association gene 5 (MDA5) antibody-positive dermatomyositis requires multidrug immunosuppressive therapy for interstitial pneumonia control, OIIA-LPD has rarely been reported. Moreover, central nervous system (CNS) OIIA-LPD has never been documented. Here, we report a case of CNS OIIA-LPD that may have been caused by treatment for MDA5 antibody-positive dermatomyositis. A 53-year-old woman was diagnosed with MDA5 dermatomyositis and treated for rapidly progressive interstitial lung disease using multidrug immunosuppressive therapy with prednisolone (PSL), tacrolimus, and intravenous cyclophosphamide pulse therapy. Seven months after treatment initiation, vomiting led to the discovery of a cerebellar tumour. The cerebellar tumour was histologically Epstein-Barr virus (EBV)-encoded small RNA-positive diffuse large B-cell lymphoma, with EBV-DNA being positive in the blood. The patient was diagnosed with OIIA-LPDs due to EBV reactivation. Chemotherapy, including high-dose methotrexate (MTX) and rituximab, prevented tumour recurrence without exacerbating interstitial lung disease. This is the first reported case of CNS OIIA-LPD with multidrug immunosuppression in a patient with MDA5 dermatomyositis. Chemotherapy, including high-dose MTX and rituximab, can be used for central OIIA-LPD without aggravating settled interstitial lung disease. The activity of MDA5 dermatomyositis during OIIA-LPD treatment may be managed with low-dose PSL.

Iguratimod is a novel oral disease-modifying antirheumatic drug (DMARD) utilised for rheumatoid arthritis, characterised by a favourable safety profile and infrequent instances of hypersensitivity, predominantly mild and cutaneous in nature. This report describes what appears to be the first reported case of severe, noncutaneous anaphylaxis following a first oral dose of iguratimod. A 37-year-old woman with seropositive rheumatoid arthritis, previously stable on methotrexate, experienced acute respiratory distress, hypotension, and new-onset atrial fibrillation within 3 hours of her initial iguratimod dose. She had never experienced a medication allergy before. Examination indicated significant hypoxia and cardiovascular instability. Anaphylaxis was validated by increased serum tryptase levels. Immediate treatment included injectable epinephrine, corticosteroids, fluid resuscitation, and mechanical ventilation. Electrical cardioversion was necessary to treat atrial fibrillation. The patient was stabilised with intensive care and was discharged without complications. This case demonstrates a rare but dramatic adverse reaction to iguratimod, emphasising the necessity of including anaphylaxis in the differential diagnosis of acute cardiorespiratory collapse, even in the absence of skin signs. Clinicians must recognise that novel immunomodulatory drugs may provoke severe allergic reactions and ensure that suitable precautions and emergency protocols are established prior to commencing such therapies.