Dr. Jay Kolls, Professor and Chair of Genetics at LSU Health Sciences Center New Orleans, and colleagues wanted to identify the factors that determine why only some develop the allergy and what factors regulate tolerance or sensitisation to the mould resulting in the development of ABPA (Allergic Bronchopulmonary Aspergillosis).The environmental mould is one of the most prevalent fungal organisms inhaled by people. In asthmatics and in patients with Cystic Fibrosis (CF), it can cause significant allergic symptoms.CF causes the body to produce thick, sticky mucus that clogs the lungs, leads to infection, and blocks the pancreas, which stops digestive enzymes from reaching the intestine where they are required in order to digest food.The researchers discovered that heightened Th2 (the hormonal messengers of T-helper cells that produce an allergic response) reactivity in the ABPA group correlated with a lower average blood level of vitamin D. “We found that adding vitamin D not only substantially reduced the production of the protein driving an allergic response, but it also increased production of the proteins that promote tolerance,” notes Kolls.”The next step in our research is to conduct a clinical trial to see if vitamin D can be used to treat or prevent this complication of asthma and Cystic Fibrosis,” Kolls said. The work will be published in September 2010 issue of the Journal of Clinical Investigation.