ICD-10-CM Code D81.5

Purine nucleoside phosphorylase [PNP] deficiency

Version 2021 Billable Code

Valid for Submission

D81.5 is a billable code used to specify a medical diagnosis of purine nucleoside phosphorylase [pnp] deficiency. The code is valid for the fiscal year 2021 for the submission of HIPAA-covered transactions. The ICD-10-CM code D81.5 might also be used to specify conditions or terms like purine-nucleoside phosphorylase deficiency.

Short Description:Purine nucleoside phosphorylase [PNP] deficiency
Long Description:Purine nucleoside phosphorylase [PNP] deficiency

Index to Diseases and Injuries

The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10 code(s). The following references for the code D81.5 are found in the index:


The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:

  • Purine-nucleoside phosphorylase deficiency

Convert D81.5 to ICD-9

  • 277.2 - Purine/pyrimid dis NEC (Approximate Flag)

Code Classification

  • Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism (D50–D89)
    • Certain disorders involving the immune mechanism (D80-D89)
      • Combined immunodeficiencies (D81)

Code History

  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016
    (First year ICD-10-CM implemented into the HIPAA code set)
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021

Information for Patients

Immune System and Disorders

Your immune system is a complex network of cells, tissues, and organs that work together to defend against germs. It helps your body to recognize these "foreign" invaders. Then its job is to keep them out, or if it can't, to find and destroy them.

If your immune system cannot do its job, the results can be serious. Disorders of the immune system include

  • Allergy and asthma - immune responses to substances that are usually not harmful
  • Immune deficiency diseases - disorders in which the immune system is missing one or more of its parts
  • Autoimmune diseases - diseases causing your immune system to attack your own body's cells and tissues by mistake

NIH: National Institute of Allergy and Infectious Diseases

  • Agammaglobulinemia (Medical Encyclopedia)
  • Aging changes in immunity (Medical Encyclopedia)
  • Chronic granulomatous disease (Medical Encyclopedia)
  • Graft-versus-host disease (Medical Encyclopedia)
  • Histiocytosis (Medical Encyclopedia)
  • Hyperimmunoglobulin E syndrome (Medical Encyclopedia)
  • Immune response (Medical Encyclopedia)
  • Immunodeficiency disorders (Medical Encyclopedia)
  • Selective deficiency of IgA (Medical Encyclopedia)

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Purine nucleoside phosphorylase deficiency Purine nucleoside phosphorylase deficiency is a disorder of the immune system called an immunodeficiency. Immunodeficiencies are conditions in which the immune system is not able to protect the body effectively from foreign invaders such as bacteria and viruses.People with purine nucleoside phosphorylase deficiency have low numbers of immune system cells called T cells, which normally recognize and attack foreign invaders to prevent infection. Some affected individuals also have low numbers of other immune system cells called B cells, which normally help fight infections by producing immune proteins called antibodies (or immunoglobulins). These proteins target foreign invaders and mark them for destruction. The most severely affected individuals, who lack T cells and B cells, have a serious condition called severe combined immunodeficiency (SCID).The shortage of immune system cells in people with purine nucleoside phosphorylase deficiency results in repeated and persistent infections typically beginning in infancy or early childhood. Infections most commonly affect the sinuses and lungs. These infections are often caused by "opportunistic" organisms that ordinarily do not cause illness in people with a normal immune system. The infections can be very serious or life-threatening, and without successful treatment to restore immune function, children with purine nucleoside phosphorylase deficiency usually do not survive past childhood.Infants with purine nucleoside phosphorylase deficiency typically grow more slowly than healthy babies. About two-thirds of individuals with this condition also have neurological problems, which may include developmental delay, intellectual disability, difficulty with balance and coordination (ataxia), and muscle stiffness (spasticity). People with purine nucleoside phosphorylase deficiency are also at increased risk of developing autoimmune disorders, which occur when the immune system malfunctions and attacks the body's tissues and organs.
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