Pulmonary Alveolar Proteinosis: The first South African insight into this rare disease

Abstract

Background: Pulmonary alveolar proteinosis (PAP) is a rare disorder characterized by excessive accumulation of intra-alveolar surfactant related, lipoproteinaceous material. With the exception of a single pediatric case report of PAP, no data exists in Sub Saharan Africa. The aim of the study is to describe the epidemiological and clinical features of patients with PAP treated at Groote Schuur Hospital since May 2009 and their outcome after the first therapeutic whole lung lavage. Methods: 11 patients with PAP were identified using the Pulmonology whole lung lavage register. A retrospective folder review was undertaken for demographic and clinical data which was captured via a paper data capture sheet and then entered into a REDCap database for ease of statistical analysis. Findings: The median age at diagnosis was 42 years, with a male to female ratio of 1:1.2 . All the patient's tested negative for HIV. A history of smoking was seen in 63.6% (7) with median pack years of 21.5. Common symptoms at presentation included: dyspnoea (100%), dry cough (45.5%), productive cough (45.5%) and weight loss (54.5%). All patients were hypoxic at diagnosis with an average Pa02 on room air of 7.75 kPa (±1.59) and, a mean FEV1/FVC ratio of 87.60% (±7.02) of predicted. Although 36.4 % (4) were unable to perform 6 min walk tests at presentation, the remaining patients had a median distance of 287 m. No mortality was seen at 12 months, despite all patients requiring whole lung lavage during this period. Conclusions: This small, retrospective cohort offers the first insight into the demographic and clinical features of patients in Sub-Saharan Africa with PAP. Interestingly, no patients in this cohort were HIV positive. Within this small cohort very few statistically significant details can be drawn but rather a description of a rare condition. Future plans to continue data collection prospectively and expand to other centres will improve deductions made.