Blood disorders & immunity problems.
OK, so it is not HIV, but I had Leukaemia in 2008.
Fortunately, my clinical course was very smooth. I was, and am still, treated with an oral daily targetted therapy that controls the illness.
I am in complete molecular remission.
However, I had absolutley no problem getting my UK Class 1 back at all. I do have an "as and with a qualified co-pilot" restriction, so no single pilot paid stuff. However an A320 needs 2 pilots, so no problem.
I would suggest taking your case to the CAA and asking.
They are quite enligtened now. As for reduced/compromised immunity: I certainly have a slightly reduced immune system. The CAA have no problem with it. They just ask for regular Haematology reports.