Adult-onset pulmonary involvement in Niemann-Pick disease type B.

Niemann-Pick disease type B is caused by a deficiency in acid sphingomyelinase activity; among the six variants of Niemann-Pick disease known to date, it is the most frequently associated with lung involvement, a major cause of morbidity and mortality in this subtype in patients of all ages. Nevertheless, the vast majority of reports in the literature concern infantile forms, while less reported is, for several reasons, the onset in adults being consequently still poorly understood and characterized its clinical, radiographic and functional manifestations. We report a case of a 37 years-old female patient affected by subtype B since she was an infant, operated for aortic valve replacement two years before and came to our attention for the onset of a worsening exertional dyspnoea which proved, through a series of functional tests and radiological exams, to be a consequence of the diffuse lung involvement by the metabolic disorder; we performed a review on this topic through a Medline search of all the available "adult-onset" case reports published since the first description in 1964, also considering the possible association between NPDB and, more generally lysosomal storage disorders, and the valvular disease, already suggested by several Authors in previous works.