Cryoglobulinemic Vasculitis

00:00 So, what are cryoglobulins? So cryoglobulins are immunoglobulins just like any other immunoglobulin made by a B-cell that just happen to precipitate in a glass tube under cold conditions.

00:15 Cryoglobulinemic vasculitis is a small vessel vasculitis that's due to mixed cryoglobulinemia. The cause of this cryoglobulin phenomenon is in some ways idiopathic but we know that it's due to the excess production of both IgG immunoglobulins and IgM immunoglobulins typically due to a polyclonal gammopathy most often in the setting of hepatitis C though as I've listed here there's a variety of other infections, inflammatory and auto-immune etiologies that can also bring about this polyclonal gammopathy. For the purposes of the boards, when you hear cryoglobulinemic vasculitis, you should be thinking about hepatitis C. Cryoglobulinemic vasculitis tends to also run a fairly indolent course. Rarely, it can present with a somewhat acute presentation. The symptoms that you're looking for are kind of vague, no weakness, fatigue, you may certainly find palpable purpura as we're seeing in our patients images here on the right and there's oftentimes renal involvement. The renal involvement classically is going to be a membranoproliferative glomerulonephritis which can have diffuse IgM deposition in capillary loops on a renal biopsy. Remember, cryoglobulinemic vasculitis is one of the immune complex mediated small vessel vasculitides. So you're going to find immune complexes when you go looking for them. In addition, like many vasculitides, you may find a peripheral neuropathy, you may find arthralgias. The diagnosis of a cryoglobulinemic vasculitis is going to be based on serum testing and then on biopsy. Your serum testing is just a serum cryoglobulin level which, while it wouldn’t tell you for sure that that's what's causing the person's symptoms, it would at least tell you whether the patient does in fact have cryoglobulins or not. And then you're deciding between a skin biopsy and a renal biopsy, skin biopsy is certainly a lot easier and it would show a leukocytoclastic vasculitis. If you're lucky, that biopsy might also show associated cryoglobulins in the vessel lumen. Remember that cryoglobulinemic vasculitis is an immune complex-mediated small vessel vasculitis, which means you should find immune complexes deposited within the biopsy tissue. Lastly, you're going to treat with, again, corticosteroids. You might also add on rituximab or cyclophosphamide depending upon certain factors we won't go into.

02:46 Plasmapheresis is also a consideration if there's a very high burden of cryoglobulins. And of course if the person is hep C positive, you should go ahead and treat the hepatitis C particularly with our robust ___ of treatment options today. In any event, I'm thinking that our 14-year-old girl is pretty unlikely to have contracted hepatitis C, I hope and we don't really have much else going for any other cryoglobulinemic vasculitis causes right now like lupus either so let's go back to our list.