Dear Editor,
On behalf of all the authors, I thank the writers for their deep interest, thorough study and in depth imaging analysis and follow up of the case report titled “Primary alveolar proteinosis – A report of two cases”.1 I agree with the writers that HRCT scan chest is an important test in the diagnosis and follow up of a case of pulmonary alveolar proteinosis (PAP).
However, we disagree with the writers about listing HRCT scan chest as one of the key words in the present case report. Key words are listed by authors of scientific articles to help readers to search for the articles they are interested in reading or doing research. HRCT scan chest gives a clue to the diagnosis of PAP in an appropriate clinical set up. However, PAP is a rare disease. Hence, out of more than a few hundreds of HRCT scan chest done in a centre, only a few cases will be finally diagnosed as PAP. The readers have also given at least eight causes of HRCT scan chest findings similar to PAP. Hence, listing HRCT scan chest as one of the key words in the present case report is not justified as it is unlikely to help many readers searching for articles on PAP or whole lung lavage (WLL).
Both the cases were treated at peripheral hospitals as pulmonary tuberculosis. This has been mentioned in the case report. The patients were evaluated subsequently at the tertiary care centre with HRCT scan chest, bronchoscopy, bronchoalveolar lavage (BAL) and lung biopsy, which confirmed the diagnosis of PAP. Readers will agree that HRCT scan chest alone cannot confirm a diagnosis of PAP without BAL and/or histopathological findings.
Response to WLL is evaluated clinically (both symptoms and signs), and by objective physiological parameters (which include forced vital capacity (FVC), DLCO, PO2 at rest and with exercise), along with X-ray and HRCT scan chest.2 In the present case report, both patients showed improvement in clinical and physiological parameters following WLL. Similar responses were maintained when they came for follow up subsequently. But case 2 showed partial resolution in HRCT scan chest as mentioned by the readers. Similar observation has also been recorded in literature: “Some patients are asymptomatic despite significant radiographic abnormalities: others undergo spontaneous remission and do not require treatment”.2
We agree with the writers that response of patients of PAP to WLL is variable; and the same has been mentioned in the case report in discussion.1,3
There was no intention of the authors to understate the role of radiology in diagnosis and management of both these cases. Rather we very much appreciate the role of radiology in both diagnosis and management of PAP. Actually management of PAP is a multispecialty team approach with pulmonologists, radiologists, pathologists, and anaesthesiologists (for single lung ventilation during WLL).
On behalf of all the authors, I again thank the writers for their critical evaluation and discussion of both the cases and for publishing the serial HRCT scan chest findings of case 2.
References
- 1.Bhattacharyya D., Barthwal M.S., Katoch C.D.S. Primary alveolar proteinosis – a report of two cases. MJAFI. 2013;69:90–93. doi: 10.1016/j.mjafi.2012.02.016. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Trapnell B.C., Puchalski J. Pulmonary alveolar proteinosis. In: Fishman A.P., Elias J.A., Fishman J.A., Grippi M.A., Senior R.M., Pack A.I., editors. Fishman's Pulmonary Diseases and Disorders. 4th ed. McGraw Hill Medical; New York: 2008. pp. 1312–1321. [Google Scholar]
- 3.Beccaria M., Luisetti M., Rodi G. Long-term durable benefit after whole lung lavage in pulmonary alveolar proteinosis. Eur Respir J. 2004;23(4):526–531. doi: 10.1183/09031936.04.00102704. [DOI] [PubMed] [Google Scholar]