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WGO Handbook on Diet and the Gut_2016_Final

World Digestive Health Day WDHD – May 29, 2016 This is even more outspoken and problematic in the Middle- East, North Africa, the Indian Subcontinent, and Latin America.6 Only in the first years is dietetic follow-up part of the regular follow-up. However, refractory celiac and gluten ataxia patients should be controlled by a dietician every 6-12 months. FOLLOW UP SEROLOGY IgA tissue Transglutaminase (tTgA) is the preferred method for monitoring the quality of GFD-compliance. Minor dietary mistakes are not detected by this. Interpreting this test is straightforward, a celiac patient on a GFD for at least 6-12 months should have a negative test. EMA can remain positive in follow-up during GFD for years. The tTgA levels should be as close to zero as possible, indicating a minimal antibody response to gluten, or at least show a significant and ongoing dropping. A negative test is what most celiac patients want to see some time after beginning the GFD. A normal tTgA value can sometimes be reached only after a year or more on the diet, especially if the initial value was very elevated. What matters is that the number declines consistently over time. One should be aware that in non-compliant patients, a mucosal and serological relapse might develop even after many years of gluten challenge.8 Also, there is no reliable way to monitor compliance with a GFD. Recent studies indicate that measuring the amount of the protein I-FABP in the blood may provide in the future a useful tool to supplement the currently accepted assays.9 LABORATORY FOLLOW UP A significant decrease (or normalization) of markers for malabsorption, such as fat in the stool, was the hallmark of control until the late eighties. We rarely check for this anymore as a standard procedure. For those presenting with severe malnutrition, as well as ongoing weight loss, we assess nutritional status and intestinal absorption capacity should be assessed.10 Checking if the small intestine normalizes is mandatory: hemoglobin, iron, vitamin B6, folic acid, vitamin B12, calcium, alkaline phosphatase, vitamin D, and parathyroid hormone. We advise checking for the so-called common associated autoimmune conditions (Thyroid-stimulating hormone, Thyroid hormone), and finally tTgA to check the diet adherence. The sensitivity of tTgA for the quality of diet adherence control is not well studied. The key endpoints in the clinical follow-up are normalization of weight, prevention of overweight, and mucosal healing, which means normalization of histology to Marsh 0-1. MANAGING ADULT CELIAC DISEASE IN THE OUTPATIENT CLINIC, continued HISTOLOGICAL FOLLOW-UP Rates of mucosal healing are highly variable. In some studies up to 40% of patients had persisting villous atrophy after two years and about 10% after five years on a GFD.3,11 This raises the question whether symptoms alone constitute a reliable guide to mucosal healing. Ongoing villous atrophy can lead to persisting deficiencies and problems such as osteoporosis and mimic irritable bowel syndrome (IBS). Clinical symptoms, celiac serology, and laboratory markers of inflammation are unfortunately not robust enough measures to confirm mucosal healing. Until better non-invasive tests of mucosal healing can be developed, a repeat intestinal biopsy after one year of GFD is recommended. The majority of patients diagnosed after the age of 40-45 years do have a slow normalizing histological recovery. As part of our research, we repeated intestinal biopsies after one year of dietary therapy in the mid-nineties. However, this is not our approach in 2015. We repeat biopsies only in patients with severe abnormalities, especially if diagnosed above the age of 50, or based on lack of improvement and persistent or recurrent complaints. Our principal problem is whether re-biopsies indeed change the clinical outcomes in the majority of patients. Recently Biagi et al. showed that the majority of celiac patients do not present a satisfactory histological response, and they suggested a duodenal biopsy to be the only tool that could identify patients with unsatisfactory histological response.12 ADHERENCE TO GFD So far reports never defined the frequency of monitoring for assessing compliance and outcome. Training families to adhere to GFD is important; consultation by gastroenterologists and cooperating dieticians should take place every 4-8 months in the first year. Celiac families with additional screen-detected relatives need in general fewer controls, as they are already familiar with our advice about GFD. Dietary adherence guarantees mucosal healing and at least improvement of non-gastrointestinal symptoms. Non-invasive biomarkers for complete mucosal recovery might be useful. The majority of patients who normalize rapidly, with normal diet and a BMI 20-25, need less follow-up. In general, we advise controlling those patients in the out-clinic only once every two years. Patients with a lack of improvement we see at least twice a year. In between the two-year interval follow-up we ask the general practitioner to check serum hemoglobulin, 34 WGO Handbook on DIET AND THE GUT World Digestive Health Day WDHD May 29, 2016


WGO Handbook on Diet and the Gut_2016_Final
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