Two receptors of the inflammatory molecule leukotriene B4 play opposing roles in turning inflammation ‘on’ and ‘off’ for allergic asthma and COPD, according to researchers from Japan.

The first receptor, “BLT1,” promotes inflammation; the second, “BLT2,” can weaken inflammation during an allergic reaction. Previously, BLT2 was believed to increase inflammatory reaction, according to researchers.

“Leukotriene B4 levels are elevated in the airways of the patients with asthma and COPD, and the opposite role of BLT1 and BLT2 in allergic inflammation implies that drug development should target BLT1 and BLT2 differently,” said Hiromasa Inoue, MD, study author from the Department of Pulmonary Medicine at the Graduate School of Medical and Dental Sciences at Kagoshima University in Kagoshima, Japan.

“We hope that better anti-asthma drugs or anti-COPD drugs will be produced in the future to treat millions of patients who suffer from severe asthma and COPD.”