Neutrophil abnormalities - granulomatous disease, chronic
Description
- Failure of the phagocyte respiratory (oxidative) burst -> cannot kill ingested organisms
- Phenotype: recurrent deep-seated infection with catalase-positive organisms, plus sterile granuloma formation
The organisms - the examinable list
- Catalase-positive (they destroy the microbe-derived H2O2 that CGD phagocytes would otherwise borrow)
- *Staphylococcus aureus*
- *Serratia marcescens*
- *Burkholderia cepacia* complex
- *Nocardia*
- *Aspergillus (and A. nidulans* - almost pathognomonic)
- Catalase-negative organisms such as streptococci and pneumococci are handled normally
Sites
- Lung (pneumonia, abscess), skin, lymph node (suppurative adenitis), liver abscess (staphylococcal, characteristically dense and requiring surgery), osteomyelitis, perianal abscess
Granulomatous complications
- Obstructing granulomas - gastric outlet obstruction, urinary tract, oesophagus
- Colitis indistinguishable from Crohn disease in 30-40%
6 more sections, plus exam facts
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