Summary of expression of PD-1 and PD-L1 in mastocytosis subtypes, other myeloid neoplasms, and reactive/healthy BMs using IHC
| Diagnosis . | PD-L1 expression (%)* . | PD-1 expression (%)† . |
|---|---|---|
| SM‡ | 17/22 (77) | 0/25 (0) |
| MCL‡ | 3/3 (100) | 0/4 (0) |
| ASM | 2/2 (100) | 0/2 (0) |
| SM-AHNठ| 9/12 (75) | 0/14 (0) |
| SSM | 1/2 (50) | 0/2 (0) |
| ISM | 3/4 (75) | 0/4 (0) |
| CM | 23/25 (92) | 4/27 (15) |
| MPCM | 15/17 (88) | 2/18 (11) |
| Mastocytoma | 3/3 (100) | 2/3 (67) |
| MIS | 5/5 (100) | 0/6 (0) |
| MML | 1/2 (50) | 0/2 (0) |
| MMAS§ | 0/3 (0) | 0/3 (0) |
| MPN§ | 0/16 (0) | 0/17 (0) |
| MDS§ | 0/18 (0) | 0/18 (0) |
| MDS/MPN§ | 0/5 (0) | 0/5 (0) |
| Healthy and reactive BM§ | 0/15 (0) | 0/21 (0) |
| Diagnosis . | PD-L1 expression (%)* . | PD-1 expression (%)† . |
|---|---|---|
| SM‡ | 17/22 (77) | 0/25 (0) |
| MCL‡ | 3/3 (100) | 0/4 (0) |
| ASM | 2/2 (100) | 0/2 (0) |
| SM-AHNठ| 9/12 (75) | 0/14 (0) |
| SSM | 1/2 (50) | 0/2 (0) |
| ISM | 3/4 (75) | 0/4 (0) |
| CM | 23/25 (92) | 4/27 (15) |
| MPCM | 15/17 (88) | 2/18 (11) |
| Mastocytoma | 3/3 (100) | 2/3 (67) |
| MIS | 5/5 (100) | 0/6 (0) |
| MML | 1/2 (50) | 0/2 (0) |
| MMAS§ | 0/3 (0) | 0/3 (0) |
| MPN§ | 0/16 (0) | 0/17 (0) |
| MDS§ | 0/18 (0) | 0/18 (0) |
| MDS/MPN§ | 0/5 (0) | 0/5 (0) |
| Healthy and reactive BM§ | 0/15 (0) | 0/21 (0) |
MDS/MPNs are all chronic myelomonocytic leukemia. MPNs included primary myelofibrosis (3), polycythemia vera (4), essential thrombocythemia (3), chronic myeloid leukemia (4), and chronic eosinophilic leukemia not otherwise specified (3). MDSs included 5q− syndrome (4), MDS with excess blasts (3), MDS with single-lineage dysplasia (i.e., refractory anemia) (1), MDS with multilineage dysplasia (5), MDS with single-lineage dysplasia and ring sideroblasts (4), and MDS not otherwise specified (1). MIS refers to skin lesions of mastocytosis in patients with SM or MCL.
PD-L1 positivity correlated with expression in SM (P = .0002) and CM (P = .0147), but did not correlate with subtype of SM or CM (P = not significant).
PD-1 positivity correlated with expression in CM (P = .0156) and subtype of CM (P = .0336).
MCL and SM-AHN both include a single patient with MCL-MDS/MPN-U (patient 4 from Table 2). This patient is only included once in the overall total of SM patients.
Immunohistochemical expression of PD-L1 and PD-1 refers to expression in MCs.