Hi! I'm currently being trialled on anti histamines (Fexofenadine 180mg x2 daily and Cimetidine 400mg x 2 daily), and about to start a mast cell stabilizer (sodium cromoglycate). My questions are this for anyone who is able to help... I have had bloods and urine tests done to check for mast cell via an immunologist in the UK at TDL (the doctor's lab) in London which came back negative, not a hint of mast cell. These are the results: Histamine - PLASMA 2.7 nmol/l range 0.0-9.0 Histamine - Urine 8 ug/l Creatinine - Urine 0.23 g/l Histamine/Creat Ratio 34.8 ug/g range 8-53 Urine Methyl Histamine 52.2 ug/l Methyl Histamine/Creat. ratio 141 ug/g range 34-177 Diamine Oxidase Activity >30.0 U/ml See below < 3 : Histamine intolerance indicated 3-10 : Histamine intolerance probable > 10 : Histamine intolerance improbable Histamine Rel. Urticaria Test ~ RESULT : Negative MAX HISTAMINE RELEASE: <16.5 % Max histamine release <16.5 % : Negative Max histamine release >=16.5 % : Positive I have a severe bladder wall infection and my urologist sent my biopsy off and also did the CD 117 staining to check for mast cells, the results came back and said this 'CD117 staining for mast cells show a mild increase in numbers of positively staining cells within the lamina propria'. So.. does this mean I have mast cell activation disorder? Or does it merely mean I have a 'mild' increase in mast cells (which I read can also be present in intersistial cystitis?). Basically what I'm trying to get at is, with it showing only 'mild' increase I feel it surely couldn't be causing the severity of my illness(es)? It's just another 'thing' that is wrong with me and not primarily mast cell activation? Any advice would be greatly appreciated. I am going to see my urologist tomorrow but just wondered what people thought.