Complement-Related Disorders Treatment & Management

Updated: Feb 15, 2022
  • Author: M Michael Glovsky, MD; Chief Editor: Michael A Kaliner, MD  more...
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Medical Care

No specific therapy is recommended at present for most of the complement disorders. However, hereditary angioedema does respond to specific therapy. [16] With regard to hereditary angioedema, epinephrine administered early may produce some (usually minimal) improvement.

Clonal C1-INH administered by infusion aborts acute attacks, and it also is safe and effective for surgical or dental prophylaxis. Cinryze, a purified C1 inhibitor protein, was recently approved by the US Food and Drug Administration (FDA) for the prophylactic treatment of hereditary angioedema (HAE). [17] It has not yet been FDA-approved for the treatment of acute HAE. [18] Other kallikrein inhibitors and a bradykinin receptor antagonist have been shown to reduce and shorten attacks of HAE but have not been approved for use by the FDA. The kallikrein inhibitor ecallantide (Kalbitor) was recently approved by the FDA to treat HAE. [19] Berinert, a C1 esterase inhibitor, was recently approved by the US FDA for treatment of acute abdominal and facial angioedema attacks in adolescents and adults with HAE. [20]

In the absence of clonal C1-INH, infusion of fresh frozen plasma has been used successfully in acute attacks of angioedema. Fresh frozen plasma has been used prior to dental and surgical procedures; however, this also provides substrate for C1-INH protein and may worsen angioedema, and, hence, it is not recommended for life-threatening laryngeal edema.

Danazol, a synthetic androgen, increases the serum concentration of C1-INH and prevents attacks in adults. It is not recommended in children.

Stanozolol is another attenuated androgen. It is no longer produced in the United States but may be given to the pediatric population.

Precipitating factors, such as trauma, estrogens, and angiotensin-converting enzyme inhibitors, should be avoided.

The antifibrinolytic agents, epsilon-aminocaproic acid and tranexamic acid, may be effective in both hereditary and acquired C1-INH deficiency. However, these drugs may be associated with intravascular thrombosis.

Fresh frozen plasma also has been used to restore C3 levels in persons with C3 deficiency. Therapeutic plasma exchange using fresh frozen plasma has been used to replace the deficient complement proteins, but, overall, it has not proved to be a safe and efficient mode of therapy. Its use in patients with SLE has not met with definite success.

Supportive management can prove helpful in these patients.

Every attempt should be made to identify the specific component or inhibitor defect.

With the development of fever in these patients, cultures should be obtained and the threshold for beginning antibiotic therapy should be low. The use of prophylactic antibiotics is controversial. Prophylactic antibiotics reduce the frequency of infection in patients with C6 deficiency, who are susceptible to meningococcal infection. However, concern for the development of antibiotic resistance and the duration of prophylaxis remain unresolved issues.

Make certain adequate information is provided to the patient or guardian for possible use by school, camp, or other health care personnel or physicians.

Immunization of the patient and household contacts for pneumococci, H influenzae, and N meningitidis is strongly recommended.

Replacement therapy with recombinant complement proteins may soon be possible; gene therapy may become a viable option in the future.