Pulmonary alveolar microlithiasis.

Sir,

I read with great interest the review article by Kashyap and Mohapatra[1] about pulmonary alveolar microlithiasis.

To our knowledge, there is no known effective treatment for pulmonary alveolar microlithiasis (PAM), with the exception of lung transplantation without recurrence of the disease after it.

Although corticosteroids are generally considered to be ineffective, a few authors have reported on the effect of corticosteroids. In one case, treatment with 20 mg daily of prednisolone for 6 months showed improvement on wheezing and chest tightness, but symptoms recurred when the treatment was discontinued.[2]

Treatment with corticosteroid and hydroxychloroquine showed clinical improvement in an 8-month-old infant.[3] A patient with PAM, after a varicella zoster virus infection, and concomitant antiphospholipid syndrome and discoid lupus erythematosus was treated successfully with daily inhaled budesonide and showed symptomatic improvement.[4]

There is also a report about improvement of pulmonary function and exercise tolerance with corticosteroid therapy in another child with PAM and lymphocytic interstitial pneumonitis.[5]

As our understanding of the link between the mutated SLC34A2 gene product and the presumed buildup of phosphate develops, it is hoped that new therapies to halt or slow the formation of microliths and interstitial lung disease will become available.