Patient baseline characteristics
| Characteristic | High sPDL1 (n=17) | Low sPDL1 (n=7) | Statistic |
| Starting sPD-L1 | 1650 (962 to 6663) | 108 (0 to 128) | F1,22 =36.19, p<0.001* |
| Age (years) | 61 (42 to 69) | 47 (38 to 66) | F1,22 =0.35, p=0.558* |
| Gender: F | 8 (47%) | 2 (29%) | X2 =0.70, p=0.404† |
| Active cancer: Yes | 5 (29%) | 2 (29%) | X2 =0, p=0.967† |
| Immunotherapy | X2 =2.88, p=0.237† | ||
| None | 16 (94%) | 6 (86%) | |
| Atezolizumab | 1 (6%) | 0 (0%) | |
| Pembrolizumab | 0 (0%) | 1 (14%) | |
| Plasma exchange indication | X2 =2.88, p=0.315† | ||
| CNS demyelination (myelitis, MS, NMO, myelopathy) | 5 (29%) | 5 (71%) | |
| Immune encephalitis | 2 (12%) | 0 (0%) | |
| Myasthenia gravis | 1 (5.9%) | 0 (0%) | |
| Paraneoplastic syndrome (encephalitis, neuropathy, pemphigus) | 2 (12%) | 2 (29%) | |
| Paraproteinemia (Waldenström, cryoglobulinemia, kappa gammopathy) | 3 (18%) | 0 (0%) | |
| Susac syndrome | 2 (12%) | 0 (0%) | |
| Transplant rejection (heart, kidney) | 2 (12%) | 0 (0%) | |
| Pre-TPE white cell count | 6.7 (6.1 to 10.3) | 8.8 (7.9 to 12.3) | F1,22 =0.78, p=0.385* |
| Pre-TPE hemoglobin | 12.5 (10.4 to 13.5) | 14.7 (13.5 to 14.9) | F1,22 =8.60, p=0.008* |
| Pre-TPE creatinine | 0.90 (0.79 to 1.55) | 0.710 (0.63 to 0.89) | F1,22 =3.82, p=0.063* |
Patients undergoing therapeutic plasma exchange (TPE) are compared by starting soluble programmed death-ligand 1 (sPD-L1) level above or below survival cut-off established in patients with melanoma (0.277 ng/mL). For categorical variables, n (%) is given. For continuous variables, mean (quartiles) is given.
*Kruskal-Wallis.
†Pearson.
CNS, central nervous system; MS, multiple sclerosis; NMO, neuromyelitis optica.