Waldenström's macroglobulinemia laboratory findings

Laboratory findings consistent with the diagnosis of Waldenstrom’s macroglobulinemia include any cytopenia, lymphocytosis, monocytosis, elevated levels of LDH, Beta-2 microglobulin, uric acid, and urea & creatinine, elevated ESR, hypercalcemia, hyponatremia, positive rheumatoid factor, positive cryoglobulins, positive direct anti-globulin test, positive cold agglutinin titre, proteinuria, prolonged bleeding time, prolonged prothrombin time, prolonged activated partial thromboplastin time, prolonged thrombin time and peripheral smear shows plasmacytoid lymphocytes, normocytic normochromic red blood cells and rouleaux formation.

• WM is mostly suspected when a patient has low blood counts and/or high levels of unusual protein levels on blood tests.
• Usually after that, a blood test called serum protein electrophoresis is ordered to find out what type of protein is there.
• Mostly, only after these tests are done that a biopsy of either the bone marrow or a lymph node is considered to confirm the WM diagnosis.
• Laboratory findings consistent with the diagnosis of Waldenstrom’s macroglobulinemia include:^[1]

• Anemia:
  • Seen in 40% of newly diagnosed patients and in 80% of symptomatic patients with Waldenstrom’s macroglobulinemia
  • Multi-factorial causes including: decreased RBC synthesis due to bone marrow infiltration, iron deficiency due to gastrointestinal bleeding, and chronic inflammation
• Thrombocytopenia:
  • Due to bone marrow infiltration
• Neutropenia:
  • Due to bone marrow infiltration
• Lymphocytosis
• Monocytosis

• Plasmacytoid lymphocytes
• Normocytic normochromic red blood cells
• Rouleaux formation

• Elevated lactate dehydrogenase (LDH):^[2]
  • Level indicates the extent of the disease
• Elevated urea and creatinine
  • Rarely
• Electrolyte abnormalities
  • Hypercalcemia
  • Hyponatremia
• Elevated erythrocyte sedimentation rate (ESR)
• Elevated uric acid levels
• Positive rheumatoid factor
• Positive cryoglobulins
• Positive direct anti-globulin test
• Positive cold agglutinin titre
• Elevated beta-2-microglobulin in proportion to tumor mass
  • Needed to evaluate prognosis

• Prolonged bleeding time^[3]
  • Possibly due to interaction between platelet membrane glycoproteins and IgM paraprotein
• Prolonged prothrombin time
• Prolonged activated partial thromboplastin time
• Prolonged thrombin time
• Abnormalities related to fibrinogen levels

• MYD88 gene mutation has been found in more than 90% of patients with Waldenstrom’s macroglobulinemia^[4]

• This test measures the blood levels of cryoglobulins (proteins that clump together in cool temperatures and can block blood vessels)

• Cold agglutinins are antibodies that attack and kill red blood cells, especially at cooler temperatures.
• These dead cells can then build up and block blood vessels.
• A blood test can be used to detect these antibodies.

• This test measures another protein made by the cancer cells in WM.
• This protein itself doesn’t cause any problems, but it’s a useful indicator of a patient’s prognosis (outlook).
• High levels of β2M are linked with a worse outlook.

• Proteinuria

• Hepatitis C serology should be obtained for patients with cryoglobulinemia.
• Hepatitis B serology should be obtained for patients whose planned treatment includes rituximab.

• Anti-myelin–associated glycoprotein
• Anti-ganglioside M1
• Anti-sulfatide IgM antibodies

Template:WH Template:WS