Polycythemia

Polycythemia

Primary polycythemia/ Polycythemia vera

  • a.k.a polycythemia rubra vera; erythremia
  • common in age 60 – 75
  • overproduction of all three hematopoietic cell lines with predominant elevation in red cell counts
  • mutation in the JAK2 protein which regulates marrow production
  • red cells grow wildly despite a Low erythropoietin level
  • high serum leukocyte alkaline phosphate
features:
  • Headache, blurred vision, and tinnitus
  • pruritus, especially after hot bath (due to histamine release from increased numbers of basophils)
  • HTN, facial plethora, fatigue, Splenomegaly
  • Bleeding from engorged blood vessels
  • Thrombosis from hyperviscosity
Investigation,
  • elevated Hct >60%*
  • low MCV and Low iron (because of excessive usage and production)
  • however, Vit. B12 levels are elevated for unclear reason
  • exclude hypoxia first; normal Oxygen level and *low erythropoietin level in PV
* RCC also has elevated Hct, but the erythropoietin is elevated.
* A small number of patients can convert to AML.
Tx
  • initial 1st line – Phlebotomy and aspirin prevent thrombosis – target Hct 45%
  • Hydroxyurea helps lower the cell count
    • indicated in old age >70 years; has thrombosis; has a platelet count >1500; and has cardiovascular risk factors
  • Allopurinol or rasburicase protects against uric acid rise
  • Antihistamines
  • Interferon alpha may be used in refractory cases
Platelet counts elevate temporarily after spleen removal

Secondary polycythemia
Increased erythropoietin level
2° to chronic tissue hypoxia
 

Kidney cancer is an important differential diagnosis of secondary polycythemia.

Renal Cell Carcinoma is a neoplastic condition that can initially appear with many different paraneoplastic manifestations.

The initial presentation may include hypertension, flank mass, gross or microscopic hematuria, hypercalcemia, fever, weight loss, and/or polycythemia.

Polycythemia may be the presenting sign in 3% of cases of kidney cancer.

Careful evaluation is important in patients presenting with polycythemia and hematuria.

Polycythemia is secondary to a hypersecretion of tumor cytokines, including renin.

The patient’s erythropoietin level is usually high.

Surgical removal of the cancer resolves the polycythemia.

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Ferritin

Ferritin = intracelllar storage form of iron.
– closely parrel body stores of iron
So, Ferritin levels are low in IDA but normal to high in anemia of chronic disease
it may be elelvated above normal in ACD because it is an acute phase reactant that is secreted by the liver in inflammatory conditions.

Ref: USMLE secrets

Hematuria

Generally, hematuria is defined as the presence of 5 or more RBCs per high-power field in 3 of 3 consecutive centrifuged specimens obtained at least 1 week apart.

may be gross/Macroscopic or Microscopic; may be symptomatic or asymptomatic, transient or persistent, may be painful or painless and either isolated or associated with proteinuria and other urinary abnormalities.

can be of glomerular or nonglomerular origin; nephrological/medical or urological or surgical:

  • Glomerular hematuria

    • Thin basement membrane disease (benign familial hematuria)
    • Alport syndrome
    • IgA nephropathy (Berger’s dz)
    • Hemolytic-uremic syndrome (HUS)
    • Postinfectious glomerulonephritis
    • Membranoproliferative glomerulonephritis
    • Lupus nephritis
    • Anaphylactoid purpura (Henoch-Schönlein purpura)
    • PNH
    • Fibrinoid necrosis of the Glomeruli (as a result of malignant hypertension)
  • Nonglomerular hematuria

    • Fever
    • Strenuous exercise – March hematuria
    • Mechanical trauma (masturbation)
    • Menstruation
    • Foreign bodies
    • Urinary tract infection
    • Hypercalciuria/urolithiasis
    • Sickle cell disease/trait
    • Coagulopathy
    • Tumors (BPH, Ca Prostate, TCC)
    • Drugs/toxins (NSAIDs, anticoagulants, captopril, cephalosporins, ciprofloxacin, furosemide, cyclophosphamide, ritonavir, indinavir)
    • Anatomic abnormalities (hydronephrosis, polycystic kidney disease, vascular malformations)
    • Hyperuricosuria

Workup
1. Blood : CBC, BUN & Creatinine, Coagulation studies, Sickle, Ca++, PSA, serology

2. Urine : Urianalysis, microscopy (Dysmorphic RBC -> Glomerular), Culture & Sensitivity

3. Imaging: Ultrasound, X-ray, CT/ spiral CT, IVU, Voiding cystourethrogram (MCUG), radionucleotide studies

Relative indications for renal biopsy:

  • Significant proteinuria
  • Abnormal renal function
  • Recurrent persistent hematuria.
  • Serologic abnormalities (abnormal complement, ANA, or dsDNA levels).
  • Recurrent gross hematuria.
  • A family history of end-stage renal disease

Other causes of Red Urine

Drugs : Hydroxocobalamin (for cyanide poisoning),  warfarin, phenazopyridine, rifampin, ibuprofen, and deferoxamine

Foods : Carrots, Beets, blackberries

Factitious disorder/ Malingering

Contamination of menstrual blood

 

Ref: Medscape