Case of the month: What could be causing this man’s persistently elevated ALP?

In the next in our series, Dr Keith Hopcroft asks what is going on with this young male with recurrent urinary tract symptoms and a persistently elevated ALP

A 35-year-old man attends for review, having had some recent blood tests taken for general malaise and tiredness. He has a history of urinary tract symptoms, as yet undiagnosed, for which he is awaiting a cystoscopy under urology. He takes sertraline for recurrent depression but is on no other medication and is otherwise well.

His blood test shows a raised alkaline phosphatase (ALP) of 312 U/L; the γ-Glutamyltransferase (GGT) is also raised at 250U/L, suggesting the elevated ALP is of hepatic origin. The other liver tests are normal.

Interestingly, looking back at his old LFTs, you note a similar pattern going back about 18 months. Three tests had been done for various reasons but he had either not been followed up or had defaulted follow up, so no specific action had been taken.

The ALP and GGT were similar to today’s results on each occasion, and twice the alanine aminotransferase (ALT) was moderately raised, too.

He is otherwise well, with no weight loss or abdominal pain, and he drinks only small amounts of alcohol. There is no family history of liver disease. Examination is normal and his liver is not palpable.

You explain that this problem needs a deeper dive, so you arrange a full hepatic blood screen and a liver ultrasound.

He is reviewed six weeks later. All bloods for potential causes of chronic liver disease have come back normal, including hepatitis and HIV serology. His LFTs are much the same, with raised ALP and GGT but normal ALT. The ultrasound is reported as normal.

You start to explain to him that the cause of his persistent blood test abnormality remains unclear and that you will need to get advice and guidance from the local hepatologist. At this point he shifts uncomfortably in his seat and says: ‘There’s something I probably should tell you.’

What is he about to say? Put your suggestions in the comments below! Answer to be revealed in the coming weeks…

Dr Keith Hopcroft is a GP in Essex

Have you handled a case which had a slightly surprising outcome? Perhaps an elderly man with non-vertigo dizziness? Or an unexpected cause of bradycardia? Would you like to share your case studies with us to help support and inform GPs? Please get in touch if you would like to contribute! [email protected]

For more diagnostic puzzles, see previous articles in our Case of the month series: