Table 3

Comparative analysis of clinical features in connective tissue diseases with onset after SARS-CoV-2 infection or COVID-19 vaccine administration

	Post-COVID-19 (n=24)	Post-vaccine (n=30)	P value
Age, years	47±18	55±19	0.134
Female sex, n (%)	19 (79.2)	22 (73.3)	0.618
N° vaccine doses, n (%)	2±1	3±1	0.263
ANA positive, n (%)	21 (87.5)	28 (93.3)	0.462
>1:160, n (%)	12 (57.1)	16 (57.1)	1.000
>1:640, n (%)	3 (14.3)	5 (17.8)	1.000
ESR, mm/h	19±16	28±22	0.728
CRP, mg/dL	0.75 (0.30–1.50)	0.56 (0.20–2.50)	0.551
Specific diseases
UCTD, n (%)	6 (25.0)	11 (36.7)	0.359
Anti-SSA positive, n (%)	0 (0.0)	3 (27.3)	0.159
Anti-Scl-70 positive, n (%)	2 (33.3)	2 (18.2)	0.482
SSc, n (%)	6 (25.0)	6 (20.0)	0.661
Anti-Scl-70 positive, n (%)	2 (33.3)	2 (33.3)	1.000
ACA positive, n (%)	3 (50.0)	4 (66.7)	0.558
IIM, n (%)	4 (16.7)	6 (20.0)	0.754
Anti-Mi2 positive, n (%)	1 (25.0)	2 (33.3)	0.778
Anti-Pl7 positive, n (%)	1 (25.0)	0 (0.0)	0.197
Anti-TIF1-γ, n (%)	0 (0.0)	2 (33.3)	0.197
ADM, n (%)	0 (0.0)	2 (6.7)	0.197
Anti-Mi2 positive, n (%)	0 (0.0)	1 (50.0)	N/A*
Anti-MDA5 positive, n (%)	0 (0.0)	1 (50.0)	N/A*
SLE, n (%)	2 (8.3)	1 (3.3)	0.425
Anti-ds-DNA positive, n (%)	1 (50.0)	1 (100.0)	0.386
Anti-Sm positive, n (%)	1 (50.0)	0 (0.0)	0.386
MCTD, n (%)	0 (0.0)	3 (10.0)	0.111
Anti-RNP positive, n (%)	0 (0.0)	3 (100.0)	N/A*
SjS, n (%)	1 (4.2)	0 (0.0)	0.259
SSA positive, n (%)	1 (100.0)	0 (0.0)	N/A*
Isolated acrosyndrome, n (%)	5 (20.8)	1 (3.3)	0.042
Acrocyanosis, n (%)	2 (40.0)	0 (0.0)	0.439
Raynaud’s phenomenon, n (%)	3 (60.0)	1 (100.0)	0.439
Treatment
Paracetamol, n (%)	7 (29.2)	10 (33.3)	0.743
NSAIDs, n (%)	5 (20.8)	6 (20.0)	0.940
GCs, n (%)	9 (37.5)	17 (56.7)	0.161
Intra-articular GCs, n (%)	2 (8.3)	0 (0.0)	0.107
Colchicine, n (%)	0 (0.0)	3 (10.0)	0.111
MTX, n (%)	3 (12.5)	3 (10.0)	0.771
HCQ, n (%)	4 (16.7)	6 (20.0)	0.754
AZA, n (%)	0 (0.0)	2 (6.7)	0.197
MMF, n (%)	1 (4.2)	1 (3.3)	0.872
CYC, n (%)	0 (0.0)	1 (3.3)	0.367
IVIg, n (%)	1 (4.2)	1 (3.3)	0.472
CCBs, n (%)	4 (16.7)	2 (6.7)	0.245

*Expected number in one category is equal to zero.
ACA, anti-centromere antibodies; ADM, amyopathic dermatomyositis; ANA, antinuclear antibodies; AZA, azathioprine; CCBs, calcium channel blockers; CRP, C reactive protein; CYC, cyclophosphamide; ESR, erythrocyte sedimentation rate; GCs, glucocorticoids; HCQ, hydroxychloroquine; IIM, idiopathic inflammatory myopathy; IVIg, intravenous immunoglobulin; MCTD, mixed connective tissue disease; MMF, mycophenolate mofetil; MTX, methotrexate; N/A, not applicable; NSAIDs, non-steroidal anti-inflammatory drugs; SjS, Sjögren’s syndrome; SLE, systemic lupus erythematosus; SSc, systemic sclerosis; UCTD, undifferentiated connective tissue disease.