Monday, September 27, 2010

Doc...We can't run the Complete Blood Count !!

We recently had an interesting patient admitted to our ICU. So I thought I will share this with you all.
64 yo male with h/o hypertension admitted with left hemiparesis with the CT head showing a right parietal intracerebral bleed. His BP was managed and on 3rd day was transferred to the rehab unit.
On his day of admission, the hematology laboratory called me saying that they could not run his Complete (Full) blood count due to some interference with the analyser and the blood. It wasnt a problem with the analyser, as it could run  other samples. So we sent 2 more samples. The white cell count(WCC) was 130,000 /cmm and platelet count was >1,000,000/cmm. Both were way above normal. This led to the suspicion of a bone marrow proliferative disorder.So we examined the peripheral smear...which surprisingly was normal with normal looking WCC and platelets. There were some faint bluish appearing strands in the smear. At the same time, the serum sample appeared grossly cloudy with some precipitation at the bottom.

Hematologist was called, and we decided to warm the sample to 37 C. What a surprise!!....his serum became clear (his warmed (clear looking) and unwarmed samples in the figure). We immediately ran it on the analyser..and it gave a normal WCC and platelets. So...the above phenomenon is what is called Cryoprecipitation. The gentleman had further tests done ..which showed massively elevated IgM cryoglobulins with negative rheumatoid factor (which will make it Type 1 Cryoglobulenemia). Search for a cause for Cryoglobulenemia led to a positive lambda light chain spike in his protein electrophoresis. He is awaiting a bone marrow biopsy. His most likely diagnosis would be Monoclonal Gammopathy of Unknown significance (due to absence of end organ damage) with Type 1 cryoglobulenemia.

Pseudothrombocytosis and pseudoleucocytosis have been reported in the past ..with cryoglobulins. A spurious count this high has not been documented before. Keep this in mind if your lab calls with this kind of problem. This scenario may not happen  in your lifetime...but ..if it does ask the lab to heat the sample.....You will look like a GENIUS!!
Just a word about cryoglobulins - they are immunoglobulins which precipitate at temperatures below 37 C. Depending on the type of Ig they are classified into
Type 1 - Monoclonal .contains only one type of Ig. Either IgM or IgG. rhematoid factor negative. usually associated with paraprotenemias (Multiple myeloma, MGUS, waldenstorms)
Type 2 - can be monoclonal or polyclonal. rheumatoid factor positive. usually associated with infection(commonly Hepatitis C).

8 comments:

  1. So interesting, thank you for sharing! This will definitely help me remember this now.

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