Background: The negative impact of COVID-19 in patients with ANCA associated vasculitis (AAV) and patients on rituximab (RTX) treatment have been reported (1). Risk factors for severe course of COVID-19 and increased mortality in these patients are unclear.

Objectives: To evaluate the course of COVID-19 in our AAV cohort and identifying risk factors for mortality.

Methods: Patients with AAV who were classified according to CHCC and whose scheduled last visit were after December 2019 were screened and evaluated for COVID-19 either by phone call or in the clinic. Records of patients with a history of hospital admission due to COVID-19 were evaluated. Cumulative clinical findings and treatment history were noted. Hypogammaglobulinemia (hIgG) was defined as IgG level below 700 mg/dl. All inpatients with a diagnosis of COVID-19 were screened for hIgG and IVIG was administered if necessary.

Results: Eighty-nine patients (47.2% female, mean age 56 + 12.5 (28-81)) were included into the study. The diagnosis was GPA in 56 (62.9%) and MPA in 33 (37.1%) patients. Mean follow up time was 91 + 53.4 (26-272) months. Anti-PR3 and anti-MPO were positive in 46 (51.7%) and 32 (35.9%) patients, respectively. Lower respiratory tract (LRT) involvement was present in 72 (80.9%) and 10 patients had a history of diffuse alveolar haemorrhage (DAH). Sixty-one patients (68.2%) had a history of rapidly progressive glomerulonephritis (RPGN) and 21 (23.6%) had peripheral nervous system (PNS) involvement.

Fifteen (16.9%) patients had COVID-19; 14 of them were PCR positive, one patient had symptoms and thorax CT findings compatible with COVID-19. Pulmonary infiltrates were observed in 13 patients (86.7%); 9 (60%) had severe pneumonia. Twelve patients (85.7%) were hospitalized, 6 patients (42.9%) needed ICU admission and 5 patients (35.7%) died. Tocilizumab and anakinra for hyperinflammation during COVID-19 were used in 1 (6.7%) and 4 (26.7%) patients, respectively.

Four out of five deceased patients (3 on RTX treatment, 1 with renal transplant) were in remission at the time of COVID-19. COVID-19 was detected in a patient with disease flare and DAH, during treatment with high dose steroids and plasmapheresis. hIgG was detected in all deceased patients from COVID-19 during hospital admission (mean IgG: 495±113.2 mg/dL).

Symptomatic COVID-19 was more frequent in patients with a history of DAH, RPGN and hIgG. hIgG during the follow-up was significantly associated with COVID-19 in multivariable analysis (p=0.01, OR=20,6 %95 CI (2-210). Comparison of patients who died of COVID-19 and survived showed that female sex, PNS involvement and hIgG during the clinical course and hospital admission were risk factors for increased mortality ( Table 1 ). Age, smoking, treatments, history of flares or serious infections, remission status and chronic renal insufficiency did not differ between groups.

Conclusion: The frequency and mortality from COVID-19 is found to be high in our AAV cohort compared to previous reports (1). Patients with serious lung or renal involvement are prone to symptomatic COVID-19. Previously reported severe outcomes on RTX therapy might be related to consequent hIgG. High dose IVIG treatment may not be sufficient in improving survival in AAV patients with severe COVID-19 and hIgG.

REFERENCES:

[1]Severity of COVID-19 and survival in patients with rheumatic and inflammatory diseases: data from the French RMD COVID-19 cohort of 694 patients. 2020:annrheumdis-2020-218310.

Disclosure of Interests: None declared