Cryoglobulinémies

Cryoglobulinémies are a group of disorders characterized by the presence of cryoglobulins in the blood. Cryoglobulins are proteins that precipitate (form solid particles) when the blood is cooled to temperatures below 37°C (98.6°F). These disorders are typically associated with chronic inflammatory conditions, most commonly rheumatoid arthritis and other autoimmune diseases. They can also be seen in certain infections, such as those caused by Helicobacter pylori or syphilis.

Cryoglobulinémies are classified into two main types based on the composition of the cryoglobulins:

1. Type I cryoglobulinémies: These are monoclonal, meaning they are derived from a single clone of plasma cells. They are often associated with monoclonal gammopathy of undetermined significance (MGUS) or multiple myeloma.

2. Type II cryoglobulinémies: These are mixed, consisting of both immunoglobulin (Ig) and complement proteins. They are more commonly associated with autoimmune diseases and infections.

Symptoms of cryoglobulinémies can vary widely and may include skin rashes, joint pain, fatigue, and in severe cases, kidney damage or neuropathy. Diagnosis typically involves blood tests to detect the presence of cryoglobulins and assess their type. Treatment depends on the underlying cause and may include immunosuppressive drugs, antibiotics, or other therapies aimed at controlling the underlying condition.