A recent article published in the journal Chest by Young et al* investigated the efficacy of a serological diagnostic assay for VEGF-D in Lymphangioleiomyomatosis (LAM). LAM is a rare disease and is often cited as a subgroup of Tuberous Sclerosis Complex (TSC). It presents as cystic lung disease in women and is often fatal. Renal tumours (specifically angiolypomas) are also often found in LAM patients and so at phenotypically and not least because of its involvement in TSC, LAM resembles some aspects of BHD Syndrome (I should definitively note that the lung symptoms found in BHD has never proved fatal).
The authors were able to discriminate between individuals with sporadic-LAM and TSC associated-LAM and other patients presenting with cystic lung disease (including BHD) and healthy controls. Sporadic-LAM was significantly associated with serum VEGF-D levels of 800pg/ml and TSC associated LAM with serum VEGF-D levels of approximately 600pg/ml and ultimately suggest that use of serum VEGF-D as a prognostic assay for LAM is a viable technique, and by extension supports the use of VEGF-D as a clinical biomarker.
Unfortunately the individuals in the study with BHD were found to have serum VEGF-D levels comparable to the normal controls, so any hopes of increasing the sensitivity of the assay and applying it to BHD syndrome is unfounded. The study does imply that biochemically the lung symptoms of LAM and BHD differ in the context of VEGF-D involvement but importantly show that identifying biomarkers of disease (or even specific symptoms) is clinically relevant, especially in the case of BHD Syndrome where positive identification of a BHD associated pneumothorax could initiate renal surveillance before the development of renal tumours.
* Young LR et al. Serum Vascular Endothelial Growth Factor-D Prospectively Distinguishes Lymphangioleiomyomatosis from Other Diseases. Chest. 2010 Apr 9 (Epublication ahead of print).
www.BHDsyndrome.org – the primary reference site for anyone interested in BHD Syndrome