Complement 2 deficiency

Complement 2 deficiency is a type of complement deficiency caused by any one of several different alterations in the structure of complement component 2, a part of the complement system of the immune response. It has been associated with an increase in infections, particularly bacterial infections with encapsulated organisms such as Streptococcus pneumoniae, Haemophilus influenzae type b and Neisseria meningitidis, often presenting as meningitis or sepsis. In roughly 10 percent of patients it is linked to an illness resembling systemic lupus erythematosus, with fever, rash, arthritis and glomerulonephritis, which is regarded as less severe than lupus seen with other complement deficiencies. It has also been linked to some rheumatic diseases.