A nurse is reviewing the laboratory values of a client with bone marrow suppression and is receiving filgrastim. Which of the following values would indicate an improvement in the client's condition?

Bone marrow suppression leads to decreased production of blood cells, especially white blood cells, red blood cells, or platelets depending on the cause. This condition increases the risk of infection, anemia, and bleeding. Filgrastim is a hematopoietic growth factor used to stimulate neutrophil production and improve immune function in clients with neutropenia. Monitoring improvement focuses primarily on rising white blood cell (WBC) counts, especially neutrophils. Rationale: A. A WBC count of 4,800 mm³ indicates improvement because it falls within the lower end of the normal range (approximately 4,000–11,000 mm³). This reflects effective stimulation of bone marrow production by filgrastim and a reduced risk of infection. It shows recovery from neutropenia and improved immune function. B. A WBC count of 500 mm³ indicates severe neutropenia and a high risk of life-threatening infections. This level reflects significant bone marrow suppression and lack of response to therapy. It is far below normal and represents worsening or unresolved immunosuppression. C. A hemoglobin level of 11.5 g/dL indicates mild anemia but does not reflect the therapeutic effect of filgrastim. Filgrastim primarily stimulates white blood cell production rather than red blood cell production. Therefore, hemoglobin is not the best indicator of improvement in this case. D. A platelet count of 150,000 mm³ is within normal limits but does not directly reflect the action of filgrastim. Platelet production is primarily influenced by different growth factors such as thrombopoietin or drugs like oprelvekin. Thus, this value is not the most specific indicator of response to filgrastim therapy.