Thrombocytopenia and neutropenia: A structured approach to evaluation
These algorithms and tables will help you quickly assess the severity of the 2 blood abnormalities and delineate between life-threatening and benign causes.
PRACTICE RECOMMENDATIONS
› Employ a systematic approach to the diagnosis and treatment of thrombocytopenia and neutropenia. C
› Do not transfuse platelets in patients with platelet counts >10,000/mcL who are stable and are not undergoing an invasive procedure. C
› Monitor patients on heparin therapy for >4 days for heparin-induced thrombocytopenia. C
› Monitor (for life) patients with a history of gastric bypass for the development of nutritional neutropenias. C
Strength of recommendation (SOR)
A Good-quality patient-oriented evidence
B Inconsistent or limited-quality patient-oriented evidence
C Consensus, usual practice, opinion, disease-oriented evidence, case series
From The Journal of Family Practice | 2018;67(7):E1-E8.
Non-immune-mediated DITP, resulting from myelosuppression, chemotherapeutic agents, or valproic acid, is less common.1,2
Acute and chronic alcohol use. Although alcohol is not a drug per se, it can also result in thrombocytopenia. The mechanism is the direct suppression of bone marrow, although alcohol also causes B12 and folate deficiency, further contributing to the development of the blood abnormality.1
Is there thrombosis?
In addition to exploring a connection between thrombocytopenia and the drugs a patient is taking, it’s also important to look for evidence of thrombosis. The causes of thrombocytopenia that paradoxically result in thrombosis are: disseminated intravascular coagulation, hemolytic uremic syndrome, thrombotic thrombocytopenic purpura, catastrophic antiphospholipid antibody syndrome, and the previously mentioned HIT. TABLE 24,6-9 outlines the clinical settings, laboratory findings, and treatments of thrombocytopenia associated with thrombosis.
Is an infectious cause to blame?
If the patient is ill, consider infectious causes of thrombocytopenia. Thrombocytopenia associated with infection may result from an immune-mediated response to an illness itself, to treatment of an illness, to splenic sequestration, or to bone marrow suppression. TABLE 31,9-11 lists common infections that may cause thrombocytopenia.
Of note, infection with Helicobacter pylori can cause asymptomatic thrombocytopenia via an immune-mediated mechanism.12 Eradication of H pylori results in a variable elevation in platelets, on average 30,000/mcL in 50% of patients with the infection.13
Is there pancytopenia?
A review of the peripheral smear, with attention to abnormalities in other cell lines, may assist in arriving at a diagnosis. If the peripheral smear reveals pancytopenia, then, in addition to many of the etiologies described earlier, one should also consider vitamin B12 or folate deficiency, copper deficiency, drug- and viral-induced aplastic anemia, paroxysmal nocturnal hemoglobinuria, leukemias, myelodysplastic disorders, and systemic lupus erythematosis.14 Pancytopenia is also seen with hypersplenism, which is often associated with cirrhosis.15 If the etiology isn’t readily apparent, a bone marrow biopsy may be required.
Continue to: Is immune thrombocytopenia to blame?
