Mixtures of monoclonal or polyclonal IgM, IgG, and/or IgA along with blood complement proteins such as C4 are the cryoglobulins associated with cases of infectious diseases, particularly hepatitis C infection, HIV infection, and Hepatitis C and HIV coinfection, and, less commonly or rarely, with cases of other infectious diseases such as hepatitis B infection, hepatitis A infection, cytomegalovirus infection, Epstein–Barr virus infection, Lyme disease, syphilis, lepromatous leprosy, Q fever, poststreptococcal nephritis, subacute bacterial endocarditis, coccidioidomycosis, malaria, schistosomiasis, echinococcosis, toxoplasmosis, and Kala-azar. These mixed-protein cryoglobulins are also associated with autoimmune diseases, particularly Sjögren syndrome, less commonly systemic lupus erythematosus and rheumatoid arthritis, and rarely polyarteritis nodosa, systemic sclerosis,  temporal arteritis, polymyositis, Henoch–Schönlein purpura, pemphigus vulgaris, sarcoidosis, inflammatory bowel diseases, and others. In these mixed-protein depositions, the monoclonal or polyclonal IgM typically possesses rheumatoid factor activity and therefore binds to the Fc region of polyclonal IgG antibodies, activates the blood complement system, and complexes with complement components to form precipitates composed of IgM, IgG or IgG, and complement components, particularly complement component 4 (C4). Diagnosis
Cryoglobulinemia and cryoglobulinemic disease must be distinguished from cryofibrinogenemia or cryofibrinogenemic disease, conditions which involve the cold-induced intravascular deposition of circulating native fibrinogens. These molecules precipitate at lower temperatures (e.g., 4 °C). Since cryofibrinogens are present in plasma but greatly depleted in serum, precipitation tests for them are positive in plasma but negative in serum. Cryofibrinogenemia is occasionally found in cases of cryoglobulinemic disease.
There is a potential for prolonging of the QT interval to occur as well. There have been no significant drug interactions reported with this drugs use. Dolasetron is broken down by the livers cytochrome P450 system and has little effect on the metabolism of other drugs broken down by this system. Intravenous dolasetron is contraindicated in Chemotherapy-induced nausea and vomiting (CINV). Doxorubicin and cyclophosphamide are as emetogenic as cisplatin, and preventive drugs should always be considered. The 5HT3 agonists are the mainstays of prevention and are frequently used in combination with other drugs such as corticosteroids and the NK1 receptor antagonist aprepitant. However, the FDA recently issued a drug communication stating that the injection form of dolasetron, a 5HT3 agonist, should no longer be used in adult or pediatric patients with CINV. Dolasetron injection can increase the risk of developing torsade de pointes, a potentially fatal abnormal heart rhythm. Patients with underlying heart conditions or existing heart rate or rhythm problems are at increased risk. Although the oral form of this agent can still be used, careful monitoring and correction of potassium and magnesium levels should be initiated prior to and during treatment. In addition, in older patients and in patients with heart failure, a slow heart rate, underlying cardiac disease, and those with renal impairment, monitoring with electrocardiography is indicated when this drug is used. Congenital long-QT syndrome and drugs that prolong the PR or QRS interval are contraindications to dolasetron therapy.