Pancytopenia


Pancytopenia is a medical condition in which there is significant reduction in the number of almost all blood cells.
If only two parameters from the complete blood count are low, the term bicytopenia can be used. The diagnostic approach is the same as for pancytopenia.

Causes

Iatrogenic causes of pancytopenia include chemotherapy for malignancies if the drug or drugs used cause bone marrow suppression. Rarely, drugs can cause pancytopenia.
For example, the antibiotic chloramphenicol can cause pancytopenia in some individuals.
Rarely, pancytopenia may have other causes, such as mononucleosis or other viral diseases. Increasingly, HIV is itself a cause of pancytopenia.
The mechanism of pancytopenia involves either haemopoiesis itself, decreasing blood cell productions in number, haemopoietic stem cells are displaced by malignant cells or they are being pooled /destroyed outside bone marrow. The mechanisms for pancytopenia differ according to the etiology. For example, in hemophagocytic lymphohistiocytosis there is marked inappropriate and ineffective T cell activation that leads to an increased hemophagocytic activity. The T cell activated macrophages engulf erythrocytes, leukocytes, platelets, as well as their progenitor cells. Along with pancytopenia, HLH is characterized by fever, splenomegaly, and hemophagocytosis in bone marrow, liver, or lymph nodes.

Diagnosis

Pancytopenia usually requires a bone marrow biopsy in order to distinguish among different causes.
Treatment is done to address the underlying cause. To tide over immediate crisis blood transfusion with packed red blood cells or platelet transfusion may be done. Sometimes there are obvious clinical clues to suggest underlying B12 deficiency for a cause of pancytopenia. In this selected cases even with severe anemia blood product transfusions can be avoided and vitamin B12 treatment itself suffice. In other situations like acute leukemia, Myelodysplastic syndrome, aplastic anemia etc. disease specific therapy is needed.