Table 2. Patients’ characteristics at CIP.
| Variable | All patients (n=107) | Rechallenge (n=45) | Non-rechallenge (n=62) | P value |
|---|---|---|---|---|
| Duration of drug administration (months) | 3.4 (0.2–13.9) | 2.9 (0.7–13.9) | 4.1 (0.2–12.4) | 0.17 |
| Asymptomatic | 13 (12.1) | 11 (24.4) | 2 (3.2) | 0.001* |
| Symptoms | ||||
| Fever | 19 (17.8) | 5 (11.1) | 14 (22.6) | 0.13 |
| Cough | 80 (74.8) | 30 (66.7) | 50 (80.6) | 0.10 |
| Expectoration | 61 (57.0) | 23 (51.1) | 38 (61.3) | 0.29 |
| Shortness of breath | 67 (62.6) | 20 (44.4) | 47 (75.8) | 0.001* |
| ECOG PS | <0.001* | |||
| 0–1 | 35 (32.7) | 25 (55.6) | 10 (16.1) | |
| ≥2 | 72 (67.3) | 20 (44.4) | 52 (83.9) | |
| Grade | <0.001* | |||
| 1–2 | 66 (61.7) | 40 (88.9) | 26 (41.9) | |
| 3–4 | 33 (30.8) | 5 (11.1) | 28 (45.2) | |
| 5 | 8 (7.5) | 0 | 8 (12.9) | |
| Radiological features | 0.010* | |||
| COP | 20 (18.7) | 13 (28.9) | 7 (11.3) | |
| GGO | 53 (49.5) | 14 (31.1) | 39 (62.9) | |
| NSIP | 23 (21.5) | 11 (24.4) | 12 (19.4) | |
| NOS | 7 (6.5) | 4 (8.9) | 3 (4.8) | |
| Unknown | 4 (3.7) | 3 (6.7) | 1 (1.6) | |
| Clinical type | 0.002* | |||
| Pure | 48 (44.9) | 29 (64.4) | 19 (30.6) | |
| Induced | 13 (12.1) | 4 (8.9) | 9 (14.5) | |
| Mixed | 46 (43.0) | 12 (26.7) | 34 (54.8) | |
| Progression of disease at first CIP | 18 (16.8) | 3 (6.7) | 15 (24.2) | 0.017* |
| Combined with other irAEs | 23 (21.5) | 9 (20.0) | 14 (22.6) | 0.75* |
| Laboratory values at first CIP | ||||
| IL-6, pg/mL | 14.0 (1.9–309.7) | 8.2 (1.9–31.8) | 20.7 (2.3–309.7) | 0.19 |
| IL-10, pg/mL | 3.1(0.6–20.4) | 2.9 (0.6–5.2) | 3.2 (1.9–20.4) | 0.30 |
| LDH, U/L | 276.3 (149.0–512.7) | 250.0 (149.0–307.0) | 297.4 (185.3–512.7) | 0.08 |
| ALB, g/L | 34.2 (28.0–41.5) | 37.1 (33.5–41.5) | 32.8 (28.0–36.3) | 0.001* |
| CRP, mg/L | 32.3 (1.9–318.0) | 8.2 (1.9–31.8) | 103.9 (4.8–318.0) | 0.14 |
| KL-6, U/mL | 743 (222–9,358) | 245 (222–4,022) | 1192 (391–9,358) | 0.014* |
| WBC, K/μL | 8.0 (1.0–49.7) | 7.7 (1.0–22.9) | 8.8 (3.4–49.7) | 0.12 |
| ALC, K/μL | 0.7 (0.3–2.1) | 1.3 (0.4–2.1) | 0.5 (0.3–1.3) | <0.001* |
| AEC, K/μL | 0.1 (0–0.5) | 0.2 (0.1–0.5) | 0.1 (0–0.3) | <0.001* |
| ANC, K/μL | 7.0 (2.2–18.5) | 3.3 (2.2–9.8) | 8.4 (2.3–18.5) | 0.012* |
| NLR | 8.0 (1.3–46.3) | 5.5 (1.3–13.0) | 12.8 (2.5–46.3) | <0.001* |
| Systemic corticosteroid use | 78 (72.9) | 24 (53.3) | 54 (87.1) | <0.001* |
| Outcome of CIP | <0.001* | |||
| Recovery/improved | 82 (76.6) | 42 (93.3) | 40 (64.5) | |
| Stabilized | 10 (9.3) | 2 (4.4) | 8 (12.9) | |
| Worsened/death | 12 (11.2) | 0 | 12 (19.4) | |
| Unknown | 3 (2.8) | 1 (2.2) | 2 (3.2) | |
| Time to improvement (months) | 0.8 (0.1–7.6) | 0.9 (0.1–7.6) | 0.4 (0.1–3.9) | 0.008* |
| Recurrence of CIP | 17 (15.9) | 9 (20.0) | 8 (12.9) | 0.32 |
The data are shown as n (%) or median (range). *, P<0.05. CIP, checkpoint inhibitor-related pneumonitis; ECOG PS, Eastern Cooperative Oncology Group performance status; COP, cryptogenic organizing pneumonitis; GGO, ground glass opacities; NSIP, non-specific interstitial pneumonia; NOS, pneumonitis not otherwise specified; irAEs, immune-related adverse events; IL, interleukin; LDH, lactate dehydrogenase; ALB, albumin; CRP, C-reactive protein; KL-6, Krebs von den Lungen-6; WBC, absolute white blood cell count; ALC, absolute lymphocyte count; AEC, absolute eosinophil count; ANC, absolute neutrophil count; NLR, neutrophil-to-lymphocyte ratio.