I would like to know the age. globulin (including immunoglobulin G,A,M ) levels and colonoscopic findings. Does patient have diarrhoea and have lost wieght? Is normal duodenal biopsy after remaining on gluten free diet for 1 year?. If patient is suspected to have fat malabsorption (Van de Kramer +) then 24 hour quantification of fecal fat and D xylose test may help to exclude malabsorption. Since there is signs of colonic inflammation, IBD (especially Crohn's disease) needs exclusion by fecal calprotectin test. 

I think this patient has celiac disease. He has positive genetic markers and serum serology. The duodenal biopsies must be reviewed by an expert pathologist. the first question is if the patient follow an strict gluten-free diet and if the response is positive it would be recommended to repeat the duodenal biopsies in order to discard a refractory celiac disease and in this case to treat with oral steroids

Thanks to both for responding. Doc Ray:

Sorry. I forgot calprotectin test.This test was ok. He is 28 years.

The first IGA was 50mg. Reference Range : 70-400mg.  Two months after removing gluten, IG A, G, M, E were normal.Never again were they repeated. He havent diarrhea, but he does fat in feces and "white spots" on it.For months he hasnt lost weight. He remains "stable". The duodenal biopsy was normal 3 months after the "intermediate gluten diet". Colonoscopic findings:chronic colitis and slight lymphocytic inflammation. I will consider D xylose

Doc Luis:

Do you think that in the future he may develop refractory celiac disease? I will  consider this option.

Thanks for the information

Selective IgA deficiency + Anti TTg positive + suggestive genotype in a young man may indicate celiac disease (CD).  If duodenal biopsy was done at baseline and was abnormal, the present improvement would definitely have suggested CD. Refractory celiac is a difficult to treat condition and is a predisposer of EATCL (enteropathy associated T cell lymphoma). Some patients may respond to steroid. However the only hitch in this patient is absence of florid malabsorption (weight loss, low albumin etc). Lymphocytic colitis can occur in young but often have diarrhoea without malabsortion. The lymphocytic colon inflammation may indicate similar involvement further up in the intestine in which case different types of B cell lymphoma needs exclusion also. Other pathogens that need exclusion is Giardia, Strongyloides, HIV.

How about microscopic colitis? Dos it respond to steroids?

If the patient follows strictly a GFD long-life i don´t see more problems and the refractoriness fortunately it is exceptional

I strongly recommend revision of the original duodenal biopsy (what number of samples? was the duodenal bulb sampled? what was the dietary status at the time of biopsy?). What was the IgA tTG concentration? Did you perform a IgG DGP test? I believe that diagnosis of RCD requires diagnosis first. Type II RCD is a rare disorder and exceptionally occurs in young people and with a normal BMI. 

In these cases  may be used Budesonde treatment at a dose of 9 mg/day during 2 months, with good results

Doc Bai:

Unfortunately only 3 samples were taken. Only duodenum.

Anti PDG was 2.3 Reference range. Negative: less 10.

  In that same analysis Iga Ttg was 1.1 Reference range: Up to 10. This test was in March 2017

He follows strict gluten-free, even cleans the meats before cooking them.

In this patient, CD diagnosis is not definitive. NON CELIAC GLUTEN SENSITIVITY is a possibility. Reintroduction of gluten may be tried to test relapse (including symptoms, duodenal biopsy and antibodies)   

Please go through the following article

Lymphocytic duodenitis or microscopic enteritis and gluten-related conditions: What needs to be explored? Annals of Gastroenterology 30(4):380-392 · July 2017DOI: 10.20524/aog.2017.0165 · 

Firstly, gluten free diet is mandatory.

Imunosupresive therapy with corticosteroids and/or azathioprine in cases who we havent response.

Is need to have consideration for like-coeliac disease. E.g, Olmesartan can lead duodenal mucosa like coeliacia.

Thanks Antonio

All the best for you