Cryoglobulinemia in MRCP
Frankly speaking, I thought cryoglobulinemia is not an important topic when I was sitting for my MRCP until recently I learned from my friend that actually it is a very popular topic in Part 1 and 2.
There are a few important salient points to remember for your MRCP.
( Rash on lower extremities typical of cutaneous small-vessel vasculitis due to cryoglobulinemia secondary to hepatitis C infection.- Photo from eMedicine)1) Cryoglobulin just means proteins that become insoluble in low temperature. Therefore, it is understandable that this leads to thrombosis and hyperviscosity leading to Raynaud Phenomenon.
2) There are 3 types of cryoglobulinemia according to Brouet classification- Type I, II, III. Just remember Type I is simple and Type II and III are mixed cryoglubulinemia.
3) Just main causes of Type I include lymphoproliferative disorders (eg, multiple myeloma, Waldenström macroglobulinemia). Type II and III causes are chronic inflammatory diseases such as chronic liver disease, infections (chronic HCV infection), and coexistent connective-tissue diseases (SLE, Sjögren syndrome). Mixed cryoglobulinemia is rarely associated with lymphoproliferative disorders.
4) Remember the common presentation of cryoglobulinemia is Meltzer triad, ie, purpura ( skin manifestation), arthralgia, and weakness ( neuropathy).
5) However, renal involvement is common too- the commonest type is membranoproliferative GN.
Sound easy right? I always remind my friends, if during your MRCP, they give you a case of patient with renal involvement ( proteinuria), skin rash and joint pain- always remember 2 possible diagnosis- SLE and of course cryoglobulinemia!!
