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[Immunology](https://durgical.com/en/immunology/) · [Immunodeficiencies](https://durgical.com/en/immunology/#a-immunodeficiency)

# Phagocyte defects: CGD, LAD, Chédiak–Higashi

- Topic

When neutrophils cannot reach, swallow or kill germs, deep abscesses and fungal infections appear, often with little pus.

Updated 2026-11-01

## Key points

- CGD: NADPH oxidase defect, no oxidative burst; most often X-linked (CYBB). Infections by catalase-positive germs: S. aureus, Aspergillus, Serratia, Nocardia, Burkholderia cepacia; granulomas.
- CGD screening: abnormal dihydrorhodamine (DHR) flow cytometry test; the older nitroblue tetrazolium (NBT) test stays colorless.
- LAD type 1: CD18 (β2 integrin) defect, autosomal recessive; delayed umbilical cord separation, omphalitis, infections without pus, very high neutrophil count, periodontitis.
- Chédiak–Higashi: LYST gene, autosomal recessive; giant granules in leukocytes, partial albinism, recurrent pyogenic infections, neuropathy, bleeding and a lymphoproliferative accelerated phase.
- Isolated low neutrophils (neutropenia) also cause bacterial and fungal infections: the cell count is the first test.

## What it is

Neutrophils and macrophages must leave the blood, engulf microbes and kill them with an oxidative burst and granule enzymes. Each step can fail: adhesion (LAD), killing (CGD), or granule formation (Chédiak–Higashi). The result is recurrent bacterial and fungal infections of skin, lungs, lymph nodes and liver.

## Phagocyte defects: the table to know

| Disease | Defect (gene, inheritance) | What fails | Infections and clues | Key test |
| --- | --- | --- | --- | --- |
| Chronic granulomatous disease (CGD) | NADPH oxidase subunits: CYBB X-linked (most common); CYBA, NCF1, NCF2, NCF4 autosomal recessive | Oxidative burst (superoxide) to kill engulfed microbes | Pneumonia, liver and lymph node abscesses, osteomyelitis by S. aureus, Aspergillus, Serratia, Nocardia, Burkholderia; granulomas in gut and bladder | DHR flow cytometry: no rise in fluorescence; NBT test negative |
| Leukocyte adhesion deficiency type 1 (LAD1) | ITGB2 (CD18, β2 integrin); autosomal recessive | Adhesion and exit of leukocytes from vessels | Cord falls after 3 weeks, omphalitis, skin and mucosal infections without pus, poor wound healing, severe gingivitis | Marked neutrophilia; low CD18 on leukocytes by flow cytometry |
| Chédiak–Higashi syndrome | LYST (lysosomal trafficking); autosomal recessive | Phagolysosome fusion and granule function; NK cell killing | Recurrent pyogenic infections (S. aureus, streptococci), partial albinism, peripheral neuropathy, easy bleeding, accelerated phase (HLH-like) | Giant granules in neutrophils on the blood smear |
| Myeloperoxidase deficiency | MPO; autosomal recessive; relatively common | Production of hypochlorite inside the phagolysosome | Usually no symptoms; Candida infections, especially with diabetes | MPO stain of neutrophils |

## Markers

- NADPH oxidase
- DHR test
- NBT test
- CD18
- LYST
- MPO

## Clinical notes

- Patients with CGD need avoidance of mulch, hay and decaying leaves, which can cause fungal pneumonia from Aspergillus spores.
- In CGD, catalase-negative germs (such as streptococci) are usually not a problem because they release hydrogen peroxide that the neutrophil can still use.
- Stem cell transplant can cure CGD, LAD and Chédiak–Higashi syndrome.

## Memory aid

Three questions for a neutrophil: can it get out (LAD), can it burn (CGD), are its granules normal (Chédiak–Higashi)?

## Test yourself

Think of the answer, then tap the question to see it.

## Why are patients with chronic granulomatous disease prone to catalase-positive organisms?

Catalase destroys the germ's own hydrogen peroxide, so the neutrophil, which lacks NADPH oxidase, has no peroxide left to make killing radicals.

## Which test screens for chronic granulomatous disease today?

The dihydrorhodamine (DHR) flow cytometry test, which shows no oxidative burst.

## A newborn's umbilical cord has not fallen at 4 weeks, with omphalitis and a very high neutrophil count. What is suspected?

Leukocyte adhesion deficiency type 1 (CD18 integrin defect).

## What does the blood smear show in Chédiak–Higashi syndrome?

Giant cytoplasmic granules in neutrophils and other leukocytes.

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## Related

- [Neutrophil](https://durgical.com/en/immunology/neutrophil/)
- [Phagocytosis and the respiratory burst](https://durgical.com/en/immunology/phagocytosis-and-the-respiratory-burst/)
- [Adhesion molecules: selectins and integrins](https://durgical.com/en/immunology/adhesion-molecules-selectins-and-integrins/)
- [Granulomatous inflammation](https://durgical.com/en/immunology/granulomatous-inflammation/)
- [Immunodeficiency: warning signs and the infection pattern by defect](https://durgical.com/en/immunology/immunodeficiency-warning-signs-and-the-infection-pattern-by-defect/)

## Microorganisms

- [Staphylococcus aureus](https://durgical.com/en/microbiology/staphylococcus-aureus/)
- [Aspergillus fumigatus](https://durgical.com/en/microbiology/aspergillus-fumigatus/)
- [Nocardia](https://durgical.com/en/microbiology/nocardia/)
- [Candida albicans](https://durgical.com/en/microbiology/candida-albicans/)

[← All of immunology](https://durgical.com/en/immunology/)

Educational content on the immune system; not a treatment or individual vaccination guide and no substitute for a health professional's advice. No doses are given.

Sources: [Chronic granulomatous disease](https://medlineplus.gov/genetics/condition/chronic-granulomatous-disease/) (MedlinePlus Genetics, U.S. National Library of Medicine, 2026); [Leukocyte adhesion deficiency type 1](https://medlineplus.gov/genetics/condition/leukocyte-adhesion-deficiency-type-1/) (MedlinePlus Genetics, U.S. National Library of Medicine, 2026); [Chediak-Higashi syndrome](https://medlineplus.gov/genetics/condition/chediak-higashi-syndrome/) (MedlinePlus Genetics, U.S. National Library of Medicine, 2026).

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Representative model, for educational purposes only.

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Source: https://durgical.com/en/immunology/phagocyte-defects-cgd-lad-chediak-higashi/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/immunology/phagocyte-defects-cgd-lad-chediak-higashi/