Pancytopenia is defined as lack of all types of blood cells. It includes deficiency of erythrocytes, leukocytes, platelets, and even reticulocytes. This blood cell disorder is seen in many hematological diseases, especially in megaloblastic anemia. Aplastic anemia is also a hematological disease characterized by bone marrow hypoplasia and pancytopenia .
Specific manifestations include the following:
To diagnose pancytopenia, bone marrow aspiration and biopsy are often necessary . Bone marrow in patients with pancytopenia has fatty replacement and may show relatively increased non-hematopoetic elements. Consider dysplasia as well, and exclude the possibility of metastatic tumor.
In peripheral blood smear in pancytopenia is obvious paucity of all types of blood cells. Levels of hemoglobin and hematocrit are low, but level of hemoglobin in particular erythrocytes is around normal. Life duration of red blood cells is shorter than usual. Number of leukocytes is also reduced, especially number of granulocytes (granulocytes more than lymphocytes, that's why "relative lymphocytosis" occurs). The absolute numbers of platelets and reticulocytes are also reduced.
Many peripheral blood tests exist and may be useful, such as hemoglobin electrophoresis and blood-group testing, fluorescence-activated cell sorter (FACS) profiling, fluorescent-labeled inactive toxin aerolysin (FLAER) testing, histocompatibility testing, and many others .
Pancytopenia can be treated differently. In the beginning of disease, but often not for long, blood transfusion may help to improve blood count. After a while, effectiveness of transfusion decreases. In most cases, patients are treated with drugs. If pancytopenia is suspected to be idiopathic and result of autoimmune response, the best solution is to use immunosuppressant drugs, such as corticosteroids, cyclosporine A, cyclophosphamide, thymoglobulin, and others.
In many cases, bone marrow-stimulators can be helpful. This group of drugs includes epoetin alfa, filgrastim and sargramostim. In not many cases, and among younger patients, bone marrow transplantation, or therapy with stem cells may be an option. The advantage of bone marrow transplantation compared to other kinds of treatment has been established in multicentric trials .
The outcome of patients with pancytopenia is improving because of better supportive care. The mortality is around 50% in first year after diagnosing aplastic anemia, without any treatment, but for patients that are receiving immunosuppressive treatment, 10-year survival rate is 68%, and for those who get hematopoietic cell transplantation is even higher, and amounts 73% .
Pancytopenia can be idiopathic or secondary. In more than fifty percent of cases it is idiopathic, which means that the real cause of disorder is not actually known and detected . It may be a response of body's immune system to its own substances.
In other cases, cause is well known and proven. It can be one of the physical agents, chemical agents or drugs, or the result of allergic reaction or infection. Also, sometimes pancytopenia occurs as result of bone marrow infiltration with fibrin, or lipoid or malignant cells. Sometimes, even a physiological condition as pregnancy may lead to pancytopenia, although it's very rare .
Epidemiological studies have shown that the annual incidence of aplastic anemia in Europe is 2 cases per million population . In Asia, the incidence is higher . These studies have also shown that there is no racial or sexual predisposition for aplastic anemia. However, the incidence is slightly higher within younger patients (children and youth under age of 25).
When there is insufficiency of bone marrow, it becomes fatty and empty in pluripotent hematopoetic stem cells. Still it is not defined what causes this insufficiency, and many theories tried to explain it. According to one theory, there is abnormality in structure of hematopoietic stem cells. In others, abnormality of hematopoietic microenvironment is suggested. Most likely, it is a result of immune response to different antigens, whether they are originally from outside or inside the organism .
Pancytopenia is sometimes hereditary, and it is not possible to prevent it . But in other cases, when the environmental factor is well known and detected, pancytopenia can be prevented by simple avoiding exposure (that is possible when cause is radiation, or use of drugs such as chloramphenicol, aspirin, mezanthion).
Erythrocytes have main role in oxygenating body's tissues, leukocytes defend the body against microorganisms and other antigens, and platelets are needed in hemostasis and blood coagulation. In pancytopenia, the disorder is expected in particular blood cell function. The symptoms are numerous and may include weakness, fatigue, frequent infections, bruising or spontaneous bleeding. Treatment can be various and depends on the etiology. Blood transfusion, medications such as corticosteroids, immunosuppressant drugs, bone marrow-stimulating drugs, stem-cell therapy, or bone marrow transplantation are common options. Also, sometimes removing some environmental factors may help.