Table 1.
Summary of clinical presentation and pertinent laboratory experiments
| Overall clinical manifestations | Patient 1 | Patient 2 |
|---|---|---|
| Clinical presentation | ||
| Fever | Yes | Yes |
| Cytopenia | Yes | Yes |
| Arthritis | Inflammatory polyarthritis | Joint pain only |
| Dermatitis | Neutrophilic dermatitis (Sweet syndrome) | Leukocytoclastic vasculitis |
| Pneumonitis | No | Yes |
| CBC (normal range) | ||
| WBC, ×109/L (4.3-11.3) | 2.8 | 4.9 |
| Hemoglobin, g/dL (14.8-17.8) | 7.9 | 10.7 |
| MCV, fL (81.2-96.6L) | 110 | 114 |
| Platelets ×109/L (159-439) | 121 | 71 |
| ANC, ×109/L (2.0-7.4) | 2.5 | 2.9 |
| Laboratory (normal range) | ||
| C-reactive protein, mg/dL (0-0.8) | 11.2 | 10.7 |
| ESR, mm/h (0-10) | 105 | 62 |
| Bone marrow | ||
| Circulating blasts (%) | 0 | 0 |
| Cellularity (%) | 95 | 95 |
| Blasts (%) | 1 | 4 |
| Myeloid/erythroid ratio | 2.5 | 5.6 |
| Ring sideroblasts (%) | 5 | 0 |
| Reticulin stain | MF 1/3 | MF 1/3 |
| Ancillary studies | ||
| Karyotype | Normal | Normal |
| Variants by myeloid NGS panel (VAF %) | PRPF40B p.E399D (48.4) | None |
| UBA1 variants (VAF %) | p.M41L (67.3) | p.M41V (83.6) |
Semiquantitative grading of reticulin fibrosis was performed using the MF grading system as described in the current WHO classification.8
ANC, absolute neutrophil count; CBC, complete blood count; ESR, erythrocyte sedimentation rate; MCV, mean corpuscular volume; MF marrow fibrosis; WBC, white blood cell.