Background:Myocarditis is an infrequent but potentially life-threatening inflammatory disorder and might be part of the spectrum of systemic lupus erythematosus (SLE). Little is known about the clinical and histologic features of myocarditis in SLE, especially compared to other forms of myocarditis.Objectives:to test for potential distinctive traits among myocarditis in SLE (MyoSLE), SLE without myocarditis (OnlySLE) and myocarditis without SLE (OnlyMyo)Methods:Patients with MyoSLE were identified from three centres and compared with 231 cross-sectionally enrolled patients with OnlySLE and 87 patients with OnlyMyo. MyoSLE patients were split into two groups based on myocarditis onset within (early onset) vs after (late onset) the first year from SLE diagnosis. OnlySLE patients were dichotomised in the same way based on disease duration at time of enrolment. Demographics and general clinical features were collected retrospectively. SLE disease activity index 2000 (SLEDAI-2K), SLE International Collaborating Clinics/American College of Rheumatology damage index (SDI), clinical and laboratory features were collected at time of myocarditis onset in MyoSLE and at enrolment in OnlySLE. Quantitative data are expressed as median [interquartile range].Results:Fourteen MyoSLE patients were identified, 50% with early onset. Women were equally frequent among MyoSLE (71%) and OnlySLE patients (87%) and less frequent in the OnlyMyo group (43%; p<0.001). Age was comparable among groups. Clinical features at presentation, including left ventricular ejection fraction, were similar between MyoSLE and OnlyMyo, although the former had higher levels of pro-brain natriuretic peptide (1.1 [0.4-1.8] vs 0.1 [0.1-0.5] ng/ml; p=0.004). Patients with MyoSLE also had a lower frequency of left ventricle lateral wall involvement (36 vs 68%; p=0.035) and of oedema (20 vs 71%; p=0.036) and necrosis (0 vs 64%; p=0.009) at biopsy. Antiphospholipid antibodies (aPL) were more frequent in MyoSLE (57%) compared to both OnlyMyo (16%; p=0.003) and OnlySLE (28%; p=0.031). Compared to OnlySLE, patients with MyoSLE also had a higher prevalence of aPL-syndrome (APS: 36 vs 7%; p=0.003), neuropsychiatric (NPSLE: 43 vs 19%; p=0.039) and gastrointestinal manifestations (21 vs 5%; p=0.045). Early and late onset patients had similar demographics and clinical features and did not differ from patients with OnlySLE with similar disease duration in terms of SLEDAI-2K and SDI. Late onset MyoSLE patients had a higher prevalence of NPSLE (57 vs 18%; p=0.026) and APS (57 vs 7%; p=0.001) and higher C-reactive protein levels (6 [2-12] vs 1[0-4] mg/l; p=0.024) compared to OnlySLE patients with the same disease duration.Conclusion:Demographics of patients with MyoSLE are more similar to patients with OnlySLE than to OnlyMyo patients. MyoSLE might have distinct histological and pathogenic features compared to OnlyMyo. Patients with MyoSLE show similar patterns of disease activity and accrued damage at time of myocarditis onset compared to patients with OnlySLE with the same disease duration but might diverge later on in SLE course. aPL are frequent in MyoSLE and might both contribute to the pathogenesis of myocardial inflammation and account for the high prevalence of NPSLE and APS, especially in late onset cases.References:[1]Gartshteyn Y et al., Lupus, 2020[2]Thomas G et al., J Rheumatol, 2017[3]Peretto G et al., Int J Cardiol, 2019[4]McDonnell T et al., Blood Rev, 2019Disclosure of Interests:Giuseppe Alvise Ramirez: None declared, Maria Gerosa: None declared, Giacomo De Luca Speakers bureau: SOBI, Novartis, Celgene, Pfizer, MSD, Lorenzo Beretta Grant/research support from: Pfizer, Simone Sala: None declared, Giovanni Peretto: None declared, Luca Moroni: None declared, Francesca Mastropaolo: None declared, adriana cariddi: None declared, Silvia Sartorelli: None declared, Corrado Campochiaro Speakers bureau: Novartis, Pfizer, Roche, GSK, SOBI, Enrica Bozzolo: None declared, Roberto Caporali Consultant of: AbbVie; Gilead Sciences, Inc.; Lilly; Merck Sharp & Dohme; Celgene; Bristol-Myers Squibb; Pfizer; UCB, Speakers bureau: Abbvie; Bristol-Myers Squibb; Celgene; Lilly; Gilead Sciences, Inc; MSD; Pfizer; Roche; UCB, Lorenzo Dagna Grant/research support from: The Unit of Immunology, Rheumatology, Allergy and Rare Diseases (UnIRAR) received unresctricted research/educational grants from Abbvie, Bristol-Myers Squibb, Celgene, Janssen, Merk Sharp & Dohme, Mundipharma Pharmaceuticals, Novartis, Pfizer, Roche, Sanofi-Genzyme, and SOBI., Consultant of: Prof Lorenzo Dagna received consultation honoraria from Abbvie, Amgen, Biogen, Bristol-Myers Squibb, Celltrion, Novartis, Pfizer, Roche, Sanofi-Genzyme, and SOBI.
Comparison of lupus patients with early and late onset nephritis: a study in 71 patients from a single referral center
