The Storm Beneath the Storm: MAS-HLH in Inflammatory Myopathies

An Unusual Case of Macrophage Activation Syndrome (MAS)- Hemophagocytic Lymphohistiocytosis (HLH) Triggered by Necrotizing Autoimmune Myopathy

Macrophage activation syndrome (MAS)- hemophagocytic lymphohistiocytosis (HLH) secondary to inflammatory myopathies such as dermatomyositis (DM), polymyositis (PM), and necrotizing autoimmune myopathy is exceedingly rare in the medical literature. We present the complicated diagnosis and treatment of a 41-year-old female who presented with proximal muscle weakness and shock. Following an extensive critical care workup, she was diagnosed with MAS-HLH, triggered by a newly diagnosed necrotizing autoimmune myopathy. In this case report and literature review, we would like to highlight the importance of recognizing the clinical signs of MAS-HLH in rheumatological disorders and the necessity for rapid treatment.

[Clinical analysis of 5 cases of dermatomyositis complicated with macrophage activation syndrome]

To investigate the clinical and immunological features of dermatomyositis (DM) complicated with macrophage activation syndrome (MAS). The demographic and clinical characteristics of five patients diagnosed with DM complicated with MAS hospitalized in the Department of Rheumatology and Immunology, Peking University People ' s Hospital from 2011 to 2021 were collected. The results of clinical manifestations, laboratory tests, immunological features, treatments and prognosis were analyzed and summarized. In this study, five female patients in Peking University People's Hospital with an average age of 63.8 (44.0-83.0) years and an average disease duration of 16.1 (1.5-48.0) months. All the patients had typical DM rash (such as heliotrope sign, V/shawl sign or Gottron's sign/papules). They all had muscle involvement (including myalgia or muscle weakness). Two patients had positive myositis-specific antibodies (MSAs), in which case 1 had anti-TIF1-γ antibody and case 5 had anti-NXP-2 antibody. Four patients had interstitial lung disease except case 3. All of the cases developed MAS in the active stage of DM. Common manifestations of MAS in these five patients included high-grade fever, cytopenia, decreased fibrinogen, elevated ferritin and increased soluble CD25. Case 1 presented with neutropenia (0.6×10⁹ /L), thrombocytopenia (26.0×10⁹ /L), hypofibrinogenemia (0.9 g/L), markedly elevated ferritin (26 331.0 μg/L), decreased NK cell activity. Case 2 had anaemia (hemoglobin 81.0 g/L), thrombocytopenia (55.0×10⁹ /L), hypertriglyceridemia (4.7 mmol/L), hypofibrinogenemia (1.2 g/L), elevated ferritin (>100 000.0 μg/L), hemophagocytosis in bone marrow. Case 3 had anaemia (hemoglobin 88 g/L), decreased fibrinogen (1.9 g/L), increased ferritin (>27 759.0 μg/L), splenomegaly, hemophagocytosis in bone marrow. Case 4 suffered from neutropenia(0.3×10⁹ /L), anaemia(hemoglobin 78 g/L), hypertriglyceridemia (4.2 mmol/L), hypofibrinogenemia (0.9 g/L), increased ferritin (>100 000.0 μg/L), and decreased NK cell activity. Case 5 presented anaemia (hemoglobin 60.0 g/L), thrombocytopenia (67.0×10⁹ /L), hypertriglyceridemia (12.7 mmol/L), decreased fibrinogen (1.1 g/L), and elevated ferritin (>923.0 μg/L). All the patients were treated with methylprednisone pulse therapy (200-500 mg) combined with cyclosporine while case 5 received rituximab after methylprednisone pulses. In addition, case 3 also received the combination of mycophenolate mofetil. Case 1 was given etoposide while case 4 was treated with cyclophosphamide and repeated plasmapheresis at the same time. Moreover, intravenous immunoglobulin was added meantime apart from case 3. The condition of four patients improved significantly, nevertheless case 4 experienced recurred pulmonary symptoms and died of respiratory failure. As for complications about infection, case 2 had bacterial infection with high level procalcitonin (PCT) before MAS treatment and condition was improved after empiric antibacterial therapy. Case 3 had cytomegalovirus DNAemia before diagnosis of MAS and viral titer turned negative after ganciclovir therapy. After treatment of MAS, four patients developed cytomegalovirus DNAemia except case 3, in which case 5 was co-infected with bacteria. To sum, DM complicated with MAS is relatively rare, and its patients are of ten in life-threatening condition. Early detection, treatment and prevention of infection during treatment are critical to improve the prognosis.

COVID-19 outcomes in patients with Dermatomyositis: A registry-based cohort analysis

BACKGROUND

Patients with rheumatic diseases (RDs) like DM are known to be vulnerable towards various types of infections due to aggressive disease activity mandating high dose immunosuppressive therapy. The severity of COVID-19 in RDs is limited in literature due to the heterogeneous nature of the condition. Therefore, specific details on mortality is essential to navigate any precautions required in the treatment.

OBJECTIVES

To determine outcomes of COVID-19 in DM as compared to controls, and identify the risk association of gender, race, interstitial lung disease, neoplasms, and use of immunosuppressant.

METHODS

Retrospective data of individuals with DM and COVID-19 and the general population with COVID-19 between January 2020 to August 2021 was retrieved from the TriNetX database. 1:1 Propensity Score matching was used to adjust for confounders. We assessed COVID-19 outcomes such as mortality, hospitalisation, ICU admission, severe COVID-19, mechanical ventilation (MV), acute kidney injury (AKI), venous thromboembolism (VTE), ischemic stroke, acute respiratory distress syndrome (ARDS), renal replacement therapy (RRT) and sepsis. Subgroup analyses included gender, race, ILD, cancer patients, disease-modifying rheumatic drugs (DMARDs) use, and glucocorticoids (GC) use.

RESULTS

We identified 5,574 DM patients with COVID-19, and 5,574 general population with COVID-19 (controls). DM with COVID-19 had a lower risk of mortality in comparison to controls [RR 0.76], hospitalisation [RR 0.8], severe COVID-19 [RR 0.76], AKI [RR 0.83], and sepsis [RR 0.73]. Males and African Americans were more likely to develop AKI [RR 1.35, 1.65], while African Americans had higher odds for severe COVID-19 [RR 1.62] and VTE [RR 1.54]. DM with ILD group also experienced higher odds for severe COVID-19 infection [RR 1.64], and VTE [RR 2.06]. DM patients receiving DMARDs and glucocorticoids had higher odds for hospitalisation [RR 1.46, 2.12], and sepsis [RR 3.25, 2.4] Subgroup analysis of 5-year neoplasm history amongst DM patients with COVID-19 was inadequate for meaningful comparison.

CONCLUSION

Dermatomyositis patients without comorbities have reasonable COVID-19 outcomes including mortality and hospitalisation. Black race, male gender, ILD, DMARDS and glucocorticoid users, are associated with poor outcomes.

Management of interstitial lung disease (ILD) in myositis syndromes: A practical guide for clinicians

Inflammatory myopathies are heterogeneous clinico-serological syndromes, with variable clinical manifestations. Interstitial lung disease (ILD) is a major cause of morbidity and mortality in patients with myositis. The clinical manifestation of myositis-ILD is heterogeneous, e.g., with acute-on-chronic presentations, as well as the chronic aftermath of acute disease. Here, we have largely divided myositis-ILD into three main prognostic groups which require different treatment approaches: mild-moderate (subacute), severe or progressive (acute or subacute) and rapidly progressive, life-threatening. In current clinical practice, the treatment of myositis-ILD involves immunomodulation in an induction-maintenance treatment paradigm. There is now an option to add antifibrotics to slow the progression of established fibrosis in selected cases with chronic progressive phenotype. Here, we describe current concepts in myositis-ILD and aim to provide a practical guide for clinicians on how to approach assessment, including early identification of ILD, phenotyping of patients according to clinical trajectory and likely prognosis and stratified management adopting multi-disciplinary cross-speciality expertise, with close collaboration between rheumatology and respiratory physicians.

HLH-Like Syndrome and Rhabdomyolysis in an Adolescent Patient

Hemophagocytic lymphohistiocytosis (HLH) is a rare heterogeneous group of disorders characterized by immune overactivation. It can occur because of primary genetic mutations or secondary to almost any inflammatory or infectious process. The clinical manifestations of this syndrome are varied and life-threatening and resemble those of many malignancies, infections, sepsis, and multisystem inflammatory syndrome in children. Laboratory abnormalities often are not diagnostic for HLH until late in the disease course, and the laboratory studies are send-out tests at most institutions. Thus, quickly and accurately diagnosing pediatric patients with HLH presents significant challenges to the clinician. Furthermore, there has been recent discussion in the literature regarding the use of diagnostic criteria for HLH. In this case report, we detail an adolescent male individual who developed persistent unexplained fever, rhabdomyolysis, and regional ischemic immune myopathy. To our knowledge, there is no previous report of a pediatric patient with this rare myopathy or HLH presenting with persistent rhabdomyolysis in the literature. The patient was hospitalized for a total of 61 days, with multiple treatments attempted throughout during his course of illness. In this report, we highlight the importance of using diagnostic flexibility when HLH is suspected in pediatric patients and provide insight into the unique challenges of identifying this condition.