Diagnosis and management of ITP

Diagnostic criteria for ITP

The diagnostic workup for suspected ITP is based on proving peripheral platelet destruction and strictly ruling out other causes (suppressed hematopoiesis, disseminated intravascular coagulation (DIC), splenic sequestration).

• Clinical presentation: Patients exhibit a petechial-ecchymotic (microcirculatory) type of bleeding. Physical examination reveals no pathological changes in internal organs.
• Complete blood count: There is a strictly isolated drop in platelet levels (sometimes down to single digits per high-power field). Leukocyte and erythrocyte lineages remain intact.
• Coagulogram: Characterized by prolonged bleeding time and impaired clot retraction. Coagulation is secondarily affected: a deficiency of platelet factor 3 leads to a decrease in prothrombin concentration and impaired thromboplastin synthesis. Fibrinolysis may become activated during a crisis.
• Bone marrow examination: The myelogram reveals a normal or compensatorily increased number of megakaryocytes.

Differential diagnosis

Hemorrhagic syndrome requires careful differentiation of ITP from a number of other pathologies:

1. Acute leukemia: Bone marrow examination reveals blastic metaplasia, suppressing normal hematopoietic lineages.
2. Bone marrow hypo- and aplasia: Differs by the development of pancytopenia (a decrease in all blood cell counts) in the absence of blast cells.
3. Systemic lupus erythematosus (SLE): ITP may precede the full-blown clinical picture of SLE by several years. Screening for anti-native DNA antibodies is necessary.
4. Antiphospholipid syndrome (APS): Can present as Evans syndrome (autoimmune hemolytic anemia plus thrombocytopenia). To confirm the diagnosis, lupus anticoagulant and elevated anticardiolipin antibodies must be detected twice, 12 weeks apart.
5. Thrombocytopathies: Platelet count is normal, but their function is impaired, leading to clinical bleeding. Blood smears often show macro- or microplatelets.

Basic strategy and first-line drugs

In children with acute ITP and a non-critical platelet decrease, a «wait-and-see» approach is permitted. This is permissible only if secondary causes are 100% ruled out and round-the-clock access to medical care is ensured.

During a hemorrhagic crisis, strict bed rest and a gentle (pureed, warm) diet are prescribed to prevent trauma to the mucous membranes.

1st-line therapy:

• Intravenous immunoglobulins (IVIG): Polyvalent preparations at a single dose of 0.8–1 g/kg. A repeat infusion on the next day is needed only if the platelet count is less than 50×10⁹/L.
• Glucocorticosteroids (GCS): Prednisolone (1–2 mg/kg) in a short course of up to 4 weeks with rapid tapering. In case of high risks (e.g., cerebral hemorrhage), methylprednisolone pulse therapy (20 mg/kg/day intravenously) is used.

Rescue therapy and emergency care

If initial therapy fails, 2nd-line drugs are used: cytostatics (cyclophosphamide pulse therapy at a dose of 10 mg/kg) or targeted biological drugs (monoclonal antibodies to the CD20 receptor — rituximab).

Surgical treatment (splenectomy): Performed strictly according to life-saving indications when conservative methods fail. The effectiveness of the operation is about 70%. The remaining 30% of patients will require medications even after organ removal. In children under 5 years of age, splenectomy is extremely dangerous due to the risk of severe postsplenectomy sepsis.

Emergency care and symptom management: For profuse bleeding or intracranial hemorrhage, a combination is immediately used: platelet concentrate transfusion + high-dose IVIG + GCS pulse therapy. For local hemostasis, systemic drugs (tranexamic acid, etamsylate) and packing with hemostatic sponges are used.

Class and exam questions

What else to study on this topic

• Pathogenesis of coagulation disorders in platelet factor 3 deficiency
• Protocol and rules for administering methylprednisolone pulse therapy
• Laboratory criteria for diagnosing antiphospholipid syndrome
• Prevention of postsplenectomy sepsis in children

Other topics in "Chapter 10. Diseases of the Blood and Blood-Forming Organs"

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.