Hematology Case Study - Severe Cold Agglutinin

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This patient is a 51 year old male with a history of multiple myeloma and graft vs. host disease following an organ transplant. He presents with a severe cold agglutinin that is affecting the RBC count as well as all of the RBC indices. Additionally, there are several RBC flags that are being generated.

The sample was drawn into pre-warmed EDTA tubes that were transported to the lab in a warm water bath in an attempt to prevent RBC clumping (see “Prewarmed, undiluted” results). Because of the agglutination, the RBC and HCT results are falsely decreased. This causes the RBC Agglutination flag to be generated and the MCHC to be greatly elevated generating the Turbidity/HGB Interference flag. The RBC histogram is displaying two distinct cell populations which caused the Dimorphic Population flag to be generated. The agglutinated red cells are being captured in this second cell population to the right on the RBC histogram.

In cases with high cold agglutinin titers, a plasma replacement or 1:5 dilution using warm CELLPACKTM DCL may be necessary to reduce interference. In this case a dilution was performed in the manual whole blood (WB) mode, requiring the laboratory to manually calculate the reportable results or use Caresphere™ Workflow Solution (WS) software to correct results for the dilution.

Refer to the XN-Series™ Flagging Interpretation Guide and the Sysmex white paper The Influence of RBC Counting Technology on MCHC Results for more information on management of samples with agglutination.

 

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