C1q Nephropathy

C1q nephropathy is a kidney disease in which a large amount of protein is lost in the urine. It is one of the many diseases that can cause the nephrotic syndrome. C1q is a normal protein in the immune system, and can be found floating in the circulation of most healthy people. In C1q nephropathy, however, this protein can also be found deposited throughout the kidneys. It has been thought to be a subgroup of primary focal segmental glomerulosclerosis or to be a combination of several disease groups rather than a single disease. As a disease, it is very similar to minimal change disease (MCD) and focal segmental glomerulosclerosis (FSGS). Criteria diagnosis includes C1q deposits on the kidney and no evidence of systemic lupus erythematosus. Both children and adult patients may have no symptoms, except for the presence of blood or protein in the urine, or  present with swelling of the feet and legs, high blood pressure and kidney insufficiency. The treatment of C1q nephropathy is the same as for MCD or FSGS and includes corticosteroids and other immunosuppressive agents. Further research is needed to establish C1q nephropathy as a recognized distinct clinical entity.