Ishiguro Hiroshi, Fung Man C, Inoue Yoshio, Morizane Toshio, Maekawa Yoko, Nambu Yoshihiro, Adachi Susumu
Dept. of Molecular Pathology, Graduate School of Medical and Pharmaceutical Sciences, Chiba University.
Gan To Kagaku Ryoho. 2003 Nov;30(12):2001-7.
The availability of G-CSF increases the safety margin of chemotherapy use, especially in the management of infection. This in turn makes administration of a more intense regimen of chemotherapy possible. However, this improvement in neutropenic management could lead to an undesirable concurrent rise in thrombocytopenia risk due to the higher dose of chemotherapy administered. Although mortality from thrombocytopenia is generally quite rare, transfusions of platelets are often expensive and can be associated with side effects such as fever, hypersensitivity reaction, and occasionally infection. Therefore, transfusion of platelets should be performed when it is truly indicated. In general, the threshold for platelet transfusion is accepted as being when the platelet count drops below 10,000/microliter, unless there is an obvious bleeding lesion or other coagulation abnormality, such as DIC being identified in the patients. On the other hand, thrombotic microangiopathy (TMA) can also occur as a rare complication of the malignancy itself or from the associated cancer chemotherapy. The major features of TMA are thrombocytopenia and marked increases of destroyed erythrocytes and LDH in peripheral blood. Despite a low incidence, its high mortality rate makes it important for all physicians caring for cancer patients to be aware of it, especially in view of the ready availability of successful treatments (e.g., plasma exchanges). Early diagnosis of TMA in patients receiving chemotherapy requires special attention because some characteristics of TMA are often masked by common side-effects of chemotherapy such as bone marrow suppression. Since delay in initiation of plasma exchange could result in higher mortality, urgent hematology consultation should be obtained if TMA is ever suspected.