in the blood may be measured to support or refute a particular medical diagnosis. For example, low C3 levels are associated with Systemic Lupus Erythematosus (SLE) and some types of kidney disease such as post-infectious glomerulonephritis, membranoproliferative glomerulonephritis, and shunt nephritis. .c3 may be lost in urine in nephrotic syndrome Interactions Complement component 3 has been shown to interact with Factor H. Pathology Deficiencies in C3 lead to genetic infections, usually fatal to the newborn. References Further reading External links GeneReviews/NCBI/NIH/UW entry on Atypical Hemolytic-Uremic Syndrome OMIM entries on Atypical Hemolytic-Uremic Syndrome GeneReviews/NCBI/NIH/UW entry on Dense Deposit Disease/Membranoproliferative Glomerulonephritis Type II Complement system