An Atlasglobal Airbus A321-200, registration TC-ETN performing flight KK-8850 from Trabzon (Turkey) to Riyadh (Saudi Arabia), was enroute at FL350 about 40nm northeast of Kuwait City (Kuwait) when the crew initiated an emergency descent due to the loss of cabin pressure and diverted to Kuwait City for a safe landing about 18 minutes later. A replacement Airbus A321-200 registration TC-ETJ was dispatched from Adana (Turkey) to Kuwait and reached Riyadh with a delay of 9.5 hours. The occurrence aircraft remained on the ground for about 11 hours, then positioned to Antalya (Turkey) as flight KK-9001 maintaining a maximum cruise level FL100.