# Early-onset bibasilar emphysema in a patient with PLCG2-related immune dysregulation

## TL;DR

A patient with a PLCG2 gene mutation developed early-onset emphysema, a previously unreported condition linked to this genetic disorder.

## Contribution

This case expands the known phenotypes of PLCG2-related immune dysregulation to include early-onset bibasilar emphysema.

## Key findings

- The patient had bibasilar emphysema unrelated to alpha-1 antitrypsin deficiency.
- Early-onset emphysema is a novel manifestation of PLCG2 mutations.
- Potential treatments include IVIG and corticosteroids.

## Abstract

Mutations in the PLCG2 gene, which encodes an enzyme in the intracellular signaling pathway of B lymphocytes, result in a spectrum of conditions involving frequent infections, antibody deficiencies, immune dysregulation, and cutaneous manifestations. These conditions are coined APLAID. We describe a case of early-onset bibasilar emphysema in an individual with frequent respiratory infections and immunoglobulin deficiencies, found to have a PLCG2 mutation on genetic testing. This case is unusual because the patient has bibasilar emphysema that is unrelated to alpha-1 antitrypsin deficiency, and because COPD is not a previously described manifestation of APLAID. The mechanism causing this phenotype is unclear; it is possible that frequent infections lead to lung parenchymal damage and emphysema, or perhaps there is an association between autoimmunity and emphysema. With this case, we expand the spectrum of PLCG2-related phenotypes, highlight the utility of genetic testing, and review the literature on possible treatment options including IVIG and corticosteroids.

•Unusual case of bibasilar emphysema without alpha-1 antitrypsin deficiency.•Early-onset emphysema as a novel phenotype of PLCG2 mutation.•IVIG, prednisone, and other potential treatment options for PLCG2-related conditions.

Unusual case of bibasilar emphysema without alpha-1 antitrypsin deficiency.

Early-onset emphysema as a novel phenotype of PLCG2 mutation.

IVIG, prednisone, and other potential treatment options for PLCG2-related conditions.