Table 1

ICI-aOA (total=36)

Gender
 Female17 (47.2%)
 Male19 (52.8%)
Race/ethnicity
 Caucasian34 (94.4%)
 African–American1 (2.8%)
 American–Indian1 (2.8%)
Age
 Mean age at ICI-aOA diagnosis (range)66 (51–81)
 Mean age at cancer diagnosis (range)63 (43–79)
Cancer type
 Melanoma10 (27.8%)
 NSCLC5 (13.9%)
 RCC6 (16.7%)
 Urothelial cancer6 (16.7%)
 Gynecological malignancy3 (8.3%)
 Head and neck2 (5.6%)
 Others4 (11.1%)
ICI type
 CTLA-4i0 (0.0%)
 PD-1/PD-L1i31 (86.1%)
 Combination5 (13.9%)
Size of joints involved
 Large (knees and hips)19 (52.8%)
 Small (first CMCs, DIPs and PIPs)9 (25.0%)
 Spine5 (13.9%)
 Small and large3 (8.3%)
Number of joints involved
 Single7 (19.4%)
 Multiple24 (66.7%)
 Spine5 (13.9%)
Severity of arthritis (CTCAE)
 Grade 119 (52.8%)
 Grade 214 (38.9%)
 Grade 33 (8.3%)
Presence of other irAEs
 Yes21 (58.3%)
 No15 (39.5%)
Any serological positivity (serology checked in 27 of 36 total patients)
 Yes11 (40.7%)
Antinuclear antibody (7/22)
RF (3/27)
CCP (3/24)
RF and/or CCP (5/27)
 No16 (59.3%)
Cancer outcome
 Complete response16 (44.4%)
 Partial response5 (13.9%)
 Stable disease11 (30.6%)
 Progressive disease4 (11.1%)
ICI-aOA treatment
 Local CSI only16 (44.4%)
 NSAIDs only7 (20.0%)
 Physical therapy only7 (20.0%)
 Systemic corticosteroids1 (11.4%)
 Systemic and local corticosteroids3 (8.6%)
 Other agents (acetaminophen, duloxetine and muscle relaxant)3 (8.6%)
 Viscosupplementation2 (5.7%)
 Steroid-sparing agent (HCQ)1 (2.9%)
ICI-aOA outcome
 Improved or stabilized32 (88.9%)
 Worsened4 (11.1%)
Time of symptom onset and clinical follow-up
 Median time of symptom onset after ICI start5.2 months (IQR 2–11.4, range 0–33.8)
 Median length in rheumatology clinic follow-up1.6 months (IQR 0–7, range 0–27)
  • CCP, cyclic citrullinated peptide; CMC, carpometacarpal joint; CSI, corticosteroid injection; CTCAE, Common Terminology Criteria for Adverse Events; CTLA-4i, cytotoxic T lymphocyte-associated protein 4 inhibitor; DIP, distal interphalangeal joint; HCQ, hydroxychloroquine; ICI, immune checkpoint inhibitor; ICI-aOA, ICI-activated osteoarthritis; irAE, immune-related adverse event; NSAID, non-steroidal anti-inflammatory drug; NSCLC, non-small cell lung carcinoma; PD-1/PD-L1i, programmed cell death protein 1 or programmed cell death protein ligand 1 inhibitor; PIP, proximal interphalangeal joint; RCC, renal cell carcinoma; RF, rheumatoid factor.