The family of a Bradford teenager who has undergone a lung transplant operation are facing an anxious wait after tests revealed his body might be rejecting the organ.

Harrison Smith, 15, who has cystic fibrosis, waited two years on the transplant waiting list before he had the operation last November.

Since then he has travelled back to Great Ormond Street Children's Hospital in London for regular biopsies to check the lung's condition.

His mum, Joann McQuillan, 36, said latest tests had revealed a problem.

She said: "He had lost a bit of lung capacity, so there could be a bit of a rejection.

"We are waiting for the hospital to ring to say when we can go back down and do the biopsy to find out exactly what is causing the problem.

"We are worried to say the least.

"We are just hoping the lung isn't rejected, and that it will be a bit of fluid that can be drained out or a bit of infection that can be treated.

"They say it might not be a rejection because he had a biopsy four weeks ago and everything was clear, but you just can't say either way until after the biopsy."

Miss McQuillan said although Harrison was naturally concerned by the news, he was coping admirably.

She said: "He was worried at the time when they mentioned the rejection because that is the worst thing we could think of, but he's such a strong lad.

"I think he has been able to put it to the back of his mind and think about it later."

Harrison was able to attend a party at the Guide Post Hotel, Low Moor, last Friday to celebrate his 15th birthday and the completion of the operation.

Joann said: "He had a party a couple of years ago there and he couldn't really enjoy it because he was on the oxygen.

"This time he was up and about, had a dance and was singing on the karaoke.

"To see him dance to more than one song and not be out of breath was fantastic."

Joann said Harrison was also facing side-effects from the cocktail of drugs he is on.

She said: "We found out a couple of weeks ago that one of the side effects of the anti-rejection drugs he was on was for his feet to go numb, so he sometimes has difficulties when walking.

"We are definitely glad he got the operation but we are not at that fantastic stage yet.

"We no longer need to worry about his oxygen but there are other problems that come with that, and its difficult financially because his dad hasn't gone back to work.

"But we will get there and I'm hoping that he will be able to do all the things he couldn't do before."