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Polycythemia (Rubra) Vera       SXDX  |  RX        See also  Polycythemia / Erythrocytosis  

A clonal cell hematologic malignant disorder with excessive erythroid, myeloid and megakaryocytic elements in the bone marrow. It is one of a group of myeloproliferative disorders.

Predominant age: Middle to late years, mean is 60 years (range 15-90).  Predominant sex: Male > Female (slightly)

SIGNS AND SYMPTOMS: Early stages may produce no symptoms      

CAUSES: unknown

DIFFERENTIAL DIAGNOSIS

  1. Secondary polycythemias
  2. Hemoglobinopathy
  3. Spurious polycythemia

LABORATORY
Polycythemia with elevated Hgb, Hct, platelet counts, WBC, uric acid; decreased erythropoietin, bone marrow erythroid hyperplasia, increased leukocyte alkaline phosphatase, increased vit.B12 level, decreased folic acid level, elevated alk.phosphatase & conjungated bilirubin, hypercalcemia.
Bone marrow aspiration (red cell hyperplasia, absent iron stores) and biopsy (fibrosis during spent phase of the disease)

Drugs that may alter lab results: Diuretics may cause a spurious polycythemia.
Disorders that may alter lab results: Excessive use of alcohol or tobacco

     

Diagnosis of Polycthemia Vera (Study Group Diagnostic Criteria and Their Significance)
DX: M1 + M2 +M3, or M1 + M2 + any 2 from m1-4 category.

Evidence of a myeloproliferative state.

The diagnosis of PV requires the presence of all three major criteria (M) or the first two major criteria and two minor criteria (m). The first major criterion provides confirmation that the patient has actual polycythemia, as indicated by an elevated red cell mass. The second major criterion rules out the most common etiology of secondary polycythemia, severe arterial hypoxemia, by demonstrating a normal or only moderately reduced arterial oxygen saturation. The third criterion, evidence of a myeloproliferative syndrome, is provide either by the third major criterion, splenomegaly, or by two of the four minor criteria.

     

TREATMENT
Individualized management necessary. Dependent on many factors - age, disease duration, disease phenotype, complications, disease activity.

Currently, phlebotomy is mainstay of therapy.
Beyond that, differences exist among authorities about use and effectiveness of myelosuppressives.

Phlebotomy: To reduce hematocrit to approximately 45%. Performed as often as every 2 or 3 days until normal hematocrit reached. Phlebotomies of 250-500 m/L. Reduce to 250-350 m/L in elderly patients or patients with cardiovascular disease. Phlebotomy repeated as necessary for maintenance. If patient cannot tolerate phlebotomy - chemotherapy (hydroxyurea is the least mutagenic agent) or radiation therapy.
Phlebotomy offers prompt and effective reduction of the red cell mass and blood volume to normal values. Many patients can be maintained in an essentially normal state by phlebotomy together with a few simple adjuvants, when necessary, to control hyperuricemia or pruritus.

Concomitant therapy possibilities, e.g., some form of myelosuppression, radioactive phosphorus (in elderly patients)

Other therapy

Adjunctive  Therapy:

Summary and Recommendations for Treatment       

Although treatment with phlebotomy, 32 P, or a variety of chemotherapeutic agents is effective and prolongs survival, no modality is clearly the best for everyone. The following recommendations represent a reasonable approach. More detailed recommendations have been published by the Polycythemia Vera Study Group

  1. Most newly diagnosed patients should undergo phlebotomy to obtain symptomatic control of polycythemia. The rate and volume of phlebotomy is dictated by the patient's clinical status, as outlined in the section on phlebotomy above. The hematocrit should be reduced to the upper normal range (approximately 0.45).
  2. The long-term therapy chosen to control PV varies according to the patient's clinical status. Young patients (under 50) with no history of thrombosis and without severe thrombocytosis (greater than 1000 × 103 /muL) can probably be managed best with phlebotomy alone, with a target hematocrit of 0.45. The addition of aspirin, 325 mg per day or less, may be beneficial, although this is not proven at present. Patients with a history of thrombosis, over the age of 70, or with severe thrombocytosis, should be treated with myelosuppressive agents. Patients between the ages of 50 and 70 with no history of thrombosis or severe thrombocytosis can be managed with myelosuppressive agents or phlebotomy, although the latter modality may increase their risk for thrombotic events.
  3. The current myelosuppressive agent of choice is hydroxyurea. Although the additional risk of leukemia with longterm hydroxyurea therapy appears to be small, it may not be zero [198] . 32P may be useful in selected patients, in whom the potential leukemic risks are outweighed by ease of administration and limitations imposed by other clinical conditions. The role of interferon in routine therapy of PV is not established at present and merits further investigation.


POSSIBLE COMPLICATIONS

EXPECTED COURSE/PROGNOSIS

Median survival without treatment - 6 to 18 months following diagnosis

Survival up to 10 years with treatment

Some patients live, symptom-free, for 20 or more years

ASSOCIATED CONDITIONS: Budd-Chiari syndrome ,  Mesenteric artery thrombosis

Ref:
Dambro: Griffith's 5-Minute Clinical Consult, 1999 ed.-  Stanley G Smith MA, MB, FCFPC
Lee: Wintrobe's Clinical Hematology, 10th ed., Copyright © 1999
Diagnosing polycythemia vera: a paradigm shift. Mayo Clin Proc 1999;74:159-162
DxPlain - Mass. Gen. Hospital: http://dxplain.mgh.harvard.edu/dxp/dxp.pl      (5-1999)
Williams WJ, Beutler E, Erslev AJ, et al, eds: Hematology. 4th Ed. New York, McGraw-Hill, 1990
Conley CL: Polycythemia vera, diagnosis and treatment. Hosp Practice 1987; 22:107
Berk PD, et al. Therapeutic recommendations in polycythemia vera based on Polycythemia Vera Study Group protocols. Semin Hematol 1986;23:132.
Fruchtman SM, Wasserman LR. Therapeutic recomendations for polycythemia vera. In: Wasserman LR, Berk PD, Berlin NI, eds. Polycythemia Vera and the Myeloproliferative Syndromes. ed. Philadelphia: WB Saunders, 1995:337-350.