D84.1
BillableDefects in the complement system
HCC Category Mapping
V28HCC 115 — Disorders of Immunity, Neutropenia
0.369V24HCC 23 — Other Significant Endocrine and Metabolic Disorders
0.230ESRDHCC 23 — Other Significant Endocrine and Metabolic Disorders
0.000RxHCCHCC 98 — Complement Defects
0.000What This Code Means
A condition where the complement system, a group of proteins that help the immune system fight infections, is not working properly.
Coding Tips
- •Specify which complement component is deficient (C1, C2, C3, C4, etc.) if documented
- •Link to any recurrent infections or autoimmune conditions that may result from the deficiency
Clinical Significance
Defects in the complement system represent a group of immunodeficiencies affecting the complement cascade, a critical component of innate immunity involved in pathogen opsonization, inflammation, and membrane attack complex formation. Different complement component deficiencies predispose to different infections: early complement deficiencies (C1-C4) increase autoimmune disease risk, while terminal complement deficiencies (C5-C9) increase susceptibility to Neisseria infections.
Documentation Requirements
- ✓Documentation must identify which complement component is deficient (C1 through C9, factor B, factor D, factor H, properdin), include CH50 and AH50 functional assay results and individual complement component levels, clinical manifestations (recurrent Neisseria infections, lupus-like autoimmune disease, or other sequelae), and treatment plan including vaccination against Neisseria meningitidis.
Commonly Confused Codes
Code Hierarchy
└D84Other immunodeficiencies└D84.1Defects in the complement system
└D84.1Defects in the complement system