MLAB Hematology Keri Brophy-Martinez Unit 23: CHRONIC MYELOPROLIFERATIVE DISORDERS (MPD)

CHRONIC MYELOPROLIFERATIVE DISORDERS (MPD) MPD’s are characterized by a hypercellular bone marrow with increased quantities of one or more cellular lineages in the peripheral blood.

Idiopathic myelofibrosis Characteristics Marrow fibrosis 90% of attempts result in dry tap. Fibroblasts and increased collagen production lock in the marrow contents. Extramedullary hematopoiesis or myeloid metaplasia of spleen and liver NRBC’s and immature WBC’s in the peripheral blood, teardrop red cells, abnormal platelets

Idiopathic myelofibrosis Treatment Transfusion for anemia Iron, folate and B12 Steroids Splenectomy BM transplant

Idiopathic myelofibrosis Prognosis Median survival time is about 5 years from time of diagnosis.

Polycythemias Polycythemia vera Stem cell disorder characterized by a remarkable increase in red blood cell mass and total blood volume. There is also an increase in myeloid and megakaryocytic elements in the bone marrow.

Polycythemia vera Clinical features Patients have a ruddy cyanotic complexion due to congestion of blood vessels. Itching Fever and night sweats Splenomegaly Brain circulatory disorders and TIA’s Onset is usually around 60 years of age.

Polycythemia vera Laboratory features Increased red cell mass with Cr 51 Increased H&H, WBC, plts

Polycythemia vera Treatment Therapeutic phlebotomy for rapid reduction of RBC mass. Radioactive phosphorous for myelosuppression. Prognosis Survival time from diagnosis is 8-15 years 10-15% of patients convert to acute nonlymphocytic leukemia.

Secondary polycythemias There are many causes that all result in increased secretion of erythropoietin Physiologically appropriate increase in erythropoietin High altitude Chronic pulmonary disease Obesity/sleep apnea Defective oxygen transport Smoking High oxygen affinity hemoglobinopathies Physiologically inappropriate increase in erythropoietin Renal disease Neoplasms Endocrine disorders

Relative polycythemia Stress polycythemia Dehydration causes decrease plasma volume

Essential thrombocythemia Rare chronic MPD in which platelets are increased and function is abnormal. Platelet count is > 600,000 x 10 9 /L