# Significant but Temporary Efficacy of Statin for a Patient With Severe Autoimmune Pulmonary Alveolar Proteinosis: A Case Report

## TL;DR

A patient with severe autoimmune lung disease showed temporary improvement with statin therapy after standard lung lavage treatments.

## Contribution

This case report demonstrates the temporary efficacy of oral statin therapy in a severe autoimmune pulmonary alveolar proteinosis patient.

## Key findings

- The patient showed significant clinical improvement in oxygen saturation and pulmonary function after starting statin therapy.
- Respiratory failure relapsed two years after initiating statin therapy, indicating temporary efficacy.
- Statin therapy provided a promising but not long-term solution for severe autoimmune pulmonary alveolar proteinosis.

## Abstract

Autoimmune pulmonary alveolar proteinosis (APAP) is a rare autoimmune lung disorder characterised by the presence of anti‐granulocyte‐macrophage colony‐stimulating factor (GM‐CSF) antibodies. Whole‐lung lavage (WLL) therapy remains the standard treatment for severe cases. Recently, inhaled GM‐CSF therapy has been approved in Japan; however, the cost of the treatment remains a limiting factor. Several reports have suggested that oral statin therapy may be a promising therapeutic option for APAP. Herein, we report a case of severe APAP that underwent WLL therapy twice and achieved an excellent response and remarkable clinical resolution of respiratory failure after the initiation of oral statin therapy. Remarkable improvements in oxygen saturation, blood gas analysis, serum biomarker levels and pulmonary function test results were observed after statin administration. However, the efficacy was temporary, and respiratory failure relapsed 2 years after the initiation of statin therapy. Statin therapy for APAP was deemed effective but potentially temporary.

Evidence of the efficacy of statins in pulmonary alveolar proteinosis is limited and remains controversial. We report a case of severe autoimmune pulmonary alveolar proteinosis in a patient who underwent whole‐lung lavage therapy twice and achieved excellent response and remarkable clinical resolution of respiratory failure after the initiation of oral statin therapy.