Response to: 'Similarities and differences between severe COVID-19 pneumonia and anti-MDA-5 positive dermatomyositis associated rapidly progressive interstitial lung diseases: a challenge for the future' by Wang et al

Presence and Implications of Anti-Angiotensin Converting Enzyme-2 Immunoglobulin M Antibodies in Anti-Melanoma-Differentiation-Associated 5 Dermatomyositis

OBJECTIVE

Patients with anti-melanoma-differentiation-associated 5 (anti-MDA5)-positive dermatomyositis (DM) share several striking similarities to patients with SARS-CoV-2. Our objective was to assess the prevalence of anti-angiotensin converting enzyme-2 (ACE2) immunoglobulin M (IgM) antibodies, found in patients with severe SARS-CoV-2, in two independent anti-MDA5-positive DM cohorts.

METHODS

Anti-ACE2 IgM antibodies were assayed by enzyme-linked immunosorbent assay (ELISA) in two anti-MDA5-positive DM cohorts: a predominantly outpatient North American cohort (n = 52) and a Japanese cohort enriched for new-onset disease (n = 32). Additionally, 118 patients with SARS-CoV-2 with a spectrum of clinical severity were tested for anti-MDA5 antibodies by ELISA.

RESULTS

Five of fifty-two (9.6%) North American patients and five of thirty-two (15%) Japanese patients were positive for anti-ACE2 IgM. In the North American cohort, all five patients with anti-ACE2 IgM antibodies had proximal muscle weakness, had interstitial lung disease, were significantly more likely to receive pulse dose methylprednisolone (80% vs 30%, P = 0.043), and had worse forced vital capacity (median 59% predicted vs 78%, P = 0.056) compared with the anti-ACE2-IgM-negative group. In the Japanese cohort, all five anti-ACE2-IgM-positive patients also required pulse dose methylprednisolone, and three of five (60%) patients died. Japanese patients with anti-ACE2 IgM had significantly worse oxygenation, as defined by a lower partial pressure of oxygen (PaO2)/fraction of inspired oxygen (FiO2) ratio (233 vs 390, P = 0.021), and a higher alveolar-arterial oxygenation gradient (91 vs 23 mm Hg, P = 0.024) than the IgM-negative group.

CONCLUSION

We describe anti-ACE2 IgM autoantibodies in two independent cohorts with anti-MDA5-positive DM. These autoantibodies may be biomarkers for severe disease and provide insight into disease pathogenesis.

Circulating Calprotectin as a Biomarker of COVID-19 Severity

INTRODUCTION

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Although demographic and clinical parameters such as sex, age, comorbidities, genetic background and various biomarkers have been identified as risk factors, there is an unmet need to predict the risk and onset of severe inflammatory disease leading to poor clinical outcomes. In addition, very few mechanistic biomarkers are available to inform targeted treatment of severe (auto)-inflammatory conditions associated with COVID-19. Calprotectin, also known as S100A8/S100A9, MRP8/14 (Myeloid-Related Protein) or L1, is a heterodimer involved in neutrophil-related inflammatory processes. In COVID-19 patients, calprotectin levels were reported to be associated with poor clinical outcomes such as significantly reduced survival time, especially in patients with severe pulmonary disease.

AREAS COVERED

Pubmed was searched using the following keywords: Calprotectin + COVID19, S100A8/A9 + COVID19, S100A8 + COVID-19, S100A9 + COVID-19, MRP8/14 + COVID19; L1 + COVID-19 between May 2020 and 8 March 2021. The results summarized in this review provide supporting evidence and propose future directions that define calprotectin as an important biomarker in COVID-19.

EXPERT OPINION

Calprotectin represents a promising serological biomarker for the risk assessment of COVID-19 patients.

Teleconsultation experience with the idiopathic inflammatory myopathies: a prospective observational cohort study during the COVID-19 pandemic

Teleconsultation has assumed a central role in the management of chronic and disabling rheumatic diseases, such as the idiopathic inflammatory myopathies (IIM), during COVID-19. However, the feasibility, challenges encountered, and outcomes remain largely unexplored. Here, we describe our teleconsultation experience in a prospectively followed cohort of adult and juvenile IIM. 250 IIM enrolled into the MyoCite cohort (2017-ongoing) were offered the option of audio/visual teleconsultation using WhatsApp during the nationwide lockdown. Clinical outcomes (major/minor relapse) and prescription changes were compared between IIM subsets. Socio-demographic and clinico-serological characteristics of those who sought teleconsultation were compared with those who did not. 151 teleconsultations were sought over a 93 day period by 71 (52.2%) of 136 IIM (median age 38 years, F:M 4.5:1). Nearly one-third (38%) consulted on an emergency basis, with voice consultations being the primary medium of communication. Over a quarter (26.8%) reported relapse (15.5% minor, 11.3% major), these being more common in JDM [71.4%, OR 8.9 (1.5-51)] as compared with adult IIM, but similar across various antibody-based IIM subtypes. Patients who relapsed required more consultations [2(2-3) vs 1(1-2), p 0.009]. The demographic and socioeconomic profile of the patients seeking consultation (n = 71) was not different from those who did not (n = 65). Voice-based teleconsultations may be useful to diagnose and manage relapses in IIM during the pandemic. Patient education for meticulous and timely reporting may be improve care, and larger multicentre studies may identify subsets of IIM that require greater care and early tele-triage for effective management of the condition.