Brain Abscess as Severe Presentation of Specific Granule Deficiency

Area of Science:

• Immunology
• Genetics
• Hematology

Background:

• Specific Granule Deficiency (SGD) is a rare neutrophil disorder.
• It is characterized by reduced neutrophil granules, absent granule proteins, and bilobed nuclei.
• Mutations in C/EBP-ε are the most common cause of SGD, leading to susceptibility to invasive bacterial and Candida infections.

Observation:

• This report details two brothers diagnosed with SGD.
• The index patient presented with a brain abscess caused by Staphylococcus aureus, prompting his diagnosis.
• Genetic screening identified SGD in his older brother, who also had a history of recurrent cellulitis.

Findings:

• Peripheral smear revealed absent neutrophil granules.
• Flow cytometry showed reduced neutrophil granularity.
• The dihydrorhodamine (DHR) assay indicated abnormal oxidase production and reduced neutrophil function in the index patient.

Implications:

• Diagnosis of SGD requires identifying reduced or absent neutrophil granularity.
• Lifelong antibacterial and antifungal prophylaxis is crucial for managing patients with SGD.
• Hematopoietic cell transplantation offers a curative treatment option for SGD.