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  3. D50–D89
  4. D80-D89
  5. Other disorders involving the immune mechanism, not elsewhere classified (D89)

Other disorders involving the immune mechanism, not elsewhere classified (D89)

D89 codes cover a range of rare or complex immune system disorders not classified elsewhere. These include hypergammaglobulinemia, cryoglobulinemia, mast cell activation syndromes, graft-versus-host disease, autoimmune lymphoproliferative syndrome, cytokine release syndrome, and IgG4-related disease, among others.

The ICD-10 code for polyclonal hypergammaglobulinemia (D89.0) relates to increased levels of immunoglobulins in the blood, sometimes called Waldenstrom's hypergammaglobulinemic purpura. Codes like D89.1 for cryoglobulinemia address immune complexes that precipitate in cold temperatures, linked to conditions such as vasculitis or hepatitis C. Mast cell activation disorders (D89.4 series) identify abnormal mast cell responses, including mast cell activation syndrome and hereditary alpha tryptasemia. The graft-versus-host disease category (D89.81x) captures immune complications after stem cell or organ transplants, distinguishing between acute, chronic, and unspecified forms with related synonyms to clarify documentation. Other codes like D89.82 for autoimmune lymphoproliferative syndrome and D89.83 for cytokine release syndrome highlight specific immune dysregulation conditions. Thus, the D89 series provides medical coders and clinicians a precise toolset for coding diverse immune mechanism disorders that require careful differentiation for accurate clinical and billing records.

Instructional Notations

Type 1 Excludes

A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.

  • hyperglobulinemia NOS R77.1
  • monoclonal gammopathy of undetermined significance D47.2

Type 2 Excludes

A type 2 excludes note represents "Not included here". An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.

  • transplant failure and rejection T86

Clinical Terms

The following clinical terms provide additional context, helping users better understand the clinical background and common associations for each diagnosis listed in this section. Including related terms alongside ICD-10-CM codes supports coders, billers, and healthcare professionals in improving accuracy, enhancing documentation, and facilitating research or patient education.

Autoimmune Hypophysitis

Immune-mediated inflammation of the PITUITARY GLAND often associated with other autoimmune diseases (e.g., HASHIMOTO DISEASE; GRAVES DISEASE; and ADDISON DISEASE).

Autoimmune Lymphoproliferative Syndrome

Rare congenital lymphoid disorder due to mutations in certain Fas-Fas ligand pathway genes. Known causes include mutations in FAS, TNFSF6, NRAS, CASP8, and CASP10 proteins. Clinical features include LYMPHADENOPATHY; SPLENOMEGALY; and AUTOIMMUNITY.

Cryoglobulinemia

A condition characterized by the presence of abnormal quantities of CRYOGLOBULINS in the blood. Upon cold exposure, these abnormal proteins precipitate into the microvasculature leading to restricted blood flow in the exposed areas.

Cryoglobulins

Abnormal immunoglobulins, especially IGG or IGM, that precipitate spontaneously when SERUM is cooled below 37 degrees Celsius. It is characteristic of CRYOGLOBULINEMIA.

Cytokine Release Syndrome

A severe immune reaction characterized by excessive release of CYTOKINES. Symptoms include DYSPNEA; FEVER; HEADACHE; HYPOTENSION; NAUSEA; RASH; TACHYCARDIA; HYPOXIA; HYPERFERRITINEMIA, and MULTIPLE ORGAN FAILURE. It is associated with viral infections, SEPSIS; AUTOIMMUNE DISEASES and a variety of factors used in IMMUNOTHERAPY.

Hypergammaglobulinemia

An excess of GAMMA-GLOBULINS in the serum due to chronic infections or PARAPROTEINEMIAS.

Hypophysitis

Inflammation of the PITUITARY GLAND.

Keratoconjunctivitis Sicca

Drying and inflammation of the conjunctiva as a result of insufficient lacrimal secretion. When found in association with XEROSTOMIA and polyarthritis, it is called SJOGREN'S SYNDROME.

Mast Cell Activation Syndrome

A clinically and genetically heterogeneous group of mast cell disorders in which there is aberrant release of mast cell mediators with little to no accompanying proliferation of MAST CELLS.

Mast Cells

Granulated cells that are found in almost all tissues, most abundantly in the skin and the gastrointestinal tract. Like the BASOPHILS, mast cells contain large amounts of HISTAMINE and HEPARIN. Unlike basophils, mast cells normally remain in the tissues and do not circulate in the blood. Mast cells, derived from the bone marrow stem cells, are regulated by the STEM CELL FACTOR.

Pituitary Gland

A small, unpaired gland situated in the SELLA TURCICA. It is connected to the HYPOTHALAMUS by a short stalk which is called the INFUNDIBULUM.