A 47-year-old female with a history of anti-cyclic citrullinated peptide (anti-CCP) and rheumatoid factor sero-positive rheumatoid arthritis was sent to outpatient clinic with a diagnosis of neutropenia. She has not had any recent infections. Her rheumatoid arthritis mainly affects her hands and has been under control with etanercept therapy. During her physical exam, it is noticed that her spleen is 4 cm below the costal margin, and she has bilateral swelling of the MCP joints; all other findings are normal.
Her CBC is as follows: WBC: 8900/µL Absolute Neutrophil Count: 451/µL Absolute Lymphocyte Count: 7900/µL Hgb: 10.5 g/dl MCV: 89 fL PLT: 325k/µL On viewing her peripheral smear, more than 60 percent of WBCs are similar to the cell seen in the image attached. Flow cytometry of the peripheral blood shows CD3 + CD4 - CD8 + CD57 + TCRαβ + immunophenotype of the lymphocytes. TCR-γ gene…
