After using HU for about 5 years, I ran afoul of the ankle ulcer. Took about a year to beat it down. Once the ulcer was healed, we decided to use both HU and Aneglaride to balance out the side effects. Came down with a lung problem (we think) that has yet to be cured....shortness of breath with minimum exertion, on O2, and back to having HU carrying the load. Docs are not sure, nor am I, that Aneglaride was the root cause, but your reference to lung problems caught my eye and I pass this along for what it's worth.