any way to clinically distinguish cryoglobulinemia from cold agglutinins (IgM)?

[ChessMaster3000]

Either via clinical presentation or with relatively common lab tests?

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[Locrian]

Either via clinical presentation or with relatively common lab tests?

I'm not sure you'd ever be asked to make this distinction.

Cryoglobulinemia is the percipitation of proteins or macroglobulins at low temps (+/- RBC rouleaux formation this arbitrarily depends on the protein level in plasma) causing the blood to become viscous and can lead to Raynauds phenomenon.

Cold Agglutinin is an IgM antibody that binds RBCs at low temps causing RBCs to agglutinate, causing the sludging of blood and can lead to Raynauds Phenomenon.

If contrasting:
With Cryoglobulinemia, associate it with conditions where there is an overproduction of proteins or immunoglobulin. Plasma cell dyscrasias, Multiple Myeloma, especially lymphoplasmacytic Lymphoma ---> Waldenstrom macroglobulinemia.

With Cold Agglutinin, associate it with past infections with EBV or mycoplasma, with extravascular hemolysis (hemolytic anemia)
(but note that cold agglutinins may also arise from certain B cell neoplasms!)

Clinical Picture:
Patient presents with; (realize presentation varies between Multiple myeloma and Lymphoplasmacytic Lymphoma)
Raynauds Phenomenon "hands are sensitive to cold"
+/- Renal Dysfunction
+/- Hypercalcemia/Bone Pain/Bone Lesions/Recent Fractures
+/- Anemia (Tumor cells replace bone marrow, decreased hematapoesis)
Frequent bacterial infections
High Ig plasma levels (due to M proteins, functional Ig are actually severely decreased)


Patient presents with;
Raynauds Phenomenon
No Renal Involvement
Normal Calcium Levels
Normal IPlamsa Ig Levels (no M spike)
Moderate Anemia


idk if thats they best way to try to make this association... meh i tried

 

[Morsetlis]

The two will never be offered as competing answer choices. You will have to know the described mechanisms, as above, however.

 

[ChessMaster3000]

Great, thanks for the overview. I just want to add the cryoglobulinemia is associated with hepatitis C and can cause the skin rash livedo reticularis. I am not sure if Livedo would also happen with cold agglutinins