Acquired platelet function defect
DefinitionAcquired platelet function defects are diseases or conditions that cause the blood elements needed for blood clotting (platelets) to not work properly. The term "acquired" means these diseases or conditions are not present at birth.
Alternative NamesAcquired qualitative platelet disorders; Acquired disorders of platelet function
Causes, incidence, and risk factorsWith platelet disorders, there may be too many or too few platelets, or platelets that do not function well. Some conditions cause changes in both the number and function of platelets. Any platelet disorder affects blood clotting.These disorders can be present at birth (congenital), or they may develop later because of another disease or condition, or without a known cause. In many cases, the platelet count may be normal or even high, but there will be evidence of a bleeding disorder.Disorders that can cause problems in platelet function include:Chronic myelogenous leukemiaMyelofibrosisPolycythemia veraPrimary thrombocythemiaOther causes include:Kidney (renal) failureMultiple myelomaMedications such as aspirin, ibuprofen and other anti-inflammatory drugs, penicillins, phenothiazines, and prednisone (after long-term use)
SymptomsAbnormal menstrual periodsHeavy menstrual periodsProlonged menstrual bleeding (more than 5 days per menstrual period)Abnormal vaginal bleedingBleeding in the urineBleeding under the skin or in the muscles (soft tissues)Gastrointestinal bleedingBloody, dark black, or tarry bowel movementsVomiting blood or material that looks like coffee groundsNosebleedsProlonged bleeding, easy bruisingSkin rashBruisesPinpoint red spots (petechiae)
Signs and testsBleeding timePlatelet aggregation testPlatelet countPT and PTT
TreatmentTreatment is aimed at the cause of the problem.Bone marrow disorders (which may have abnormally low or high numbers of platelets) are treated with platelet transfusions, removing platelets from the blood (platelet pheresis), or chemotherapy to treat the condition.Platelet function defects caused by kidney failure are treated with dialysis or a drug called desmopressin (ddAVP).Platelet problems caused by medication are treated by stopping the medication.
Expectations (prognosis)Treating the cause of the problem usually corrects the defect.
ComplicationsProlonged bleedingSevere anemia
Calling your health care providerCall your health care provider:If you have bleeding and do not know the causeIf your symptoms get worse or do not improve after you are treated for an acquired platelet function defect
PreventionUsing medications carefully can reduce the risk of drug-related acquired platelet function defects. Treating other disorders may also reduce the risk. Some cases are not preventable.
ReferencesLopez JA, Lockhart E. Acquired disorders of platelet function. In: Hoffman R, Benz EJ, Jr, Shattil SJ, et al, eds. Hoffman Hematology: Basic Principles and Practice. 5th ed. Philadelphia, Pa: Churchill Livingstone Elsevier;2008:chap 142.McMillan R. Hemorrhagic disorders: Abnormalities of platelet and vascular function. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier;2007:chap 179.