Should relatives of coeliacs with mild clinical complaints undergo a small-bowel biopsy despite negative serology?

BACKGROUND AND OBJECTIVES

Small intestinal lesions in coeliac disease (CD) have a variable severity. Early diagnosis of CD is important because treatment allows a normal psycho-physical development, especially in children, and can avoid associated disorders. The aim of this study was to evaluate the predictive value of screening parameters for the detection and estimation of CD prevalence in first-degree relatives.

METHODS

The screening was performed in 338 first-degree relatives of 134 coeliac families. Questionnaires and a physical examination followed by haematological analyses and serologyfor IgA anti-endomysium (EMA)/IgA antigliadin (AGA) antibodies were used in orderto selectthe candidates for small-bowel biopsy. The small-bowel biopsy was indicated on the basis of clinical complaints, laboratory tests and serology performed in 96 (28%) of the study group.

RESULTS

CD was diagnosed in 17/96 cases. Six of the 17 showed total villous atrophy (VA) (Marsh IIIc), five subtotal VA (Marsh IIIb) and six partial VA (Marsh IIIa). EMA and AGA were strongly positive in the six patients whose intestinal biopsy showed total VA. However, only one coeliac out of the six patients with partial VA had positive EMA and AGA.

CONCLUSION

A significant proportion of coeliacs may be missed if cases are screened by serology only. Although endomysial antibody assay has been reported as a highly sensitive and specific test for detection of CD, we argue that using only EMA and AGA in screening is not enough for investigation of the true prevalence of CD. A combination of clinical parameters as described in this study and laboratory/serological tests is an important and practical contribution to improving the detection rate of CD.

Sensitivity of antiendomysium and antigliadin antibodies in untreated celiac disease: disappointing in clinical practice

OBJECTIVE

We have undertaken a study to assess the efficiency of serological tests in the diagnosis of celiac disease (CD) during the period January 1, 1994 to January 7, 1997. Our aim was to evaluate the sensitivity of IgA antiendomysium (EMA) and IgA antigliadin (AGA) with regard to the degree of histological abnormality in biopsy specimens of small intestine in untreated celiac disease patients and first-degree relatives.

METHODS

The study population comprised 101 cases: 85 untreated celiac patients and 16 first-degree relatives with a mean age of 42 yr (range, 2-76 yrs). Sixteen of 85 were excluded from study because they did not satisfy the study or diagnostic criteria of CD. EMA and AGA have been compared with the degree of villous atrophy (VA) in 69 celiac patients and 16 relatives according to the Marsh criteria of 1992. We divided the Marsh III histology into three subgroups as follows: Marsh IIIa (partial VA), Marsh IIIb (subtotal VA), and Marsh IIIc (total villous atrophy).

RESULTS

The specificity and positive predictive value of EMA for CD was excellent, because all EMA-positive patients (n = 42) were diagnosed with CD. The sensitivity of EMA, however, differed between CD subgroups; in patients with total VA, the sensitivity of EMA was 100% (17/17). However, in patients with partial VA (Marsh IIIa), the sensitivity of EMA was disappointing, only 9/29 (31%). Three of 72 celiacs with Marsh IIIb and Marsh IIIc had IgA deficiency and were excluded from the study. Elevated AGA has been detected in the sera of 39 of 69 (62%) patients. A combination of EMA and AGA tests showed a sensitivity of 76% (53/69). None of 16 first-degree relatives with Marsh I-II had positive EMA.

CONCLUSIONS

Interpretation of negative serology needs great awareness. Although EMA sensitivity in total villous atrophy is excellent, in partial villous atrophy the sensitivity of EMA appears to be disappointing. Our experience shows that EMA and AGA have only limited value in screening programs for CD.

Sensitivity of antiendomysium and antigliadin antibodies in untreated celiac disease: disappointing in clinical practice

OBJECTIVE

We have undertaken a study to assess the efficiency of serological tests in the diagnosis of celiac disease (CD) during the period January 1, 1994 to January 7, 1997. Our aim was to evaluate the sensitivity of IgA antiendomysium (EMA) and IgA antigliadin (AGA) with regard to the degree of histological abnormality in biopsy specimens of small intestine in untreated celiac disease patients and first-degree relatives.

METHODS

The study population comprised 101 cases: 85 untreated celiac patients and 16 first-degree relatives with a mean age of 42 yr (range, 2-76 yrs). Sixteen of 85 were excluded from study because they did not satisfy the study or diagnostic criteria of CD. EMA and AGA have been compared with the degree of villous atrophy (VA) in 69 celiac patients and 16 relatives according to the Marsh criteria of 1992. We divided the Marsh III histology into three subgroups as follows: Marsh IIIa (partial VA), Marsh IIIb (subtotal VA), and Marsh IIIc (total villous atrophy).

RESULTS

The specificity and positive predictive value of EMA for CD was excellent, because all EMA-positive patients (n = 42) were diagnosed with CD. The sensitivity of EMA, however, differed between CD subgroups; in patients with total VA, the sensitivity of EMA was 100% (17/17). However, in patients with partial VA (Marsh IIIa), the sensitivity of EMA was disappointing, only 9/29 (31%). Three of 72 celiacs with Marsh IIIb and Marsh IIIc had IgA deficiency and were excluded from the study. Elevated AGA has been detected in the sera of 39 of 69 (62%) patients. A combination of EMA and AGA tests showed a sensitivity of 76% (53/69). None of 16 first-degree relatives with Marsh I-II had positive EMA.

CONCLUSIONS

Interpretation of negative serology needs great awareness. Although EMA sensitivity in total villous atrophy is excellent, in partial villous atrophy the sensitivity of EMA appears to be disappointing. Our experience shows that EMA and AGA have only limited value in screening programs for CD.

SAT and serology in adult coeliacs, seronegative coeliac disease seems a reality

The aim of this study was to assess the correlation of sugar absorption test (SAT) using Lactulose/Mannitol/Sucrose (LMS), with IgA-endomysium (EMA), and IgA-gliadin (AGA) antibodies in relation to the severity of the intestinal mucosal damage in adult coeliacs. We have differentiated the Marsh classification in partial villous atrophy (VA) (III a), subtotal VA (III b), and total VA (III c). Twenty-nine untreated adults coeliacs, with a mean age of 47 years, range 20-76 yrs were studied over 3 years. SAT, IgA-AGA and IgA EMA were performed in 29 consecutive coeliac patients with villous atrophy on a gluten containing diets.

RESULTS

Histopathological evaluation of small intestinal mucosa showed a partial VA in 14/29, subtotal VA in 10/29 and total VA in 5/29. All coeliacs with total VA had positive EMA (5/5 100%). However in coeliacs with partial VA sensitivity of EMA was poor (4/14 29%). Sensitivity of EMA in patients with subtotal VA was 50% (5/10). AGA was raised in 3/14 (21%), 6/10 (60%), and in 4/5 (80%) coeliacs with partial, subtotal and total VA respectively. AGA was raised in 13/29 (sensitivity 45%). SAT was abnormal in 26/29 (sensitivity: 89%). One patient had abnormal SAT, EMA and AGA. Eleven of 29 patients (38%) were negative for AGA and EMA, but SAT was abnormal in 10 of them. One patient was positive for EMA, negative for AGA, normal for SAT. EMA and/or AGA were positive in 18/29 (sensitivity 62%). Our study suggests that negative predictive value of serology should be interpreted cautiously since coeliacs with partial VA are negative in serology. Over the last ten years SAT and EMA have been accepted as screening tools for CD. SAT seems to be more sensitive than serology. However there is no standardized agreement in the literature for serology and SAT. A combination of SAT and serology may provide a good sensitivity in order to detect that subgroup of coeliacs with milder histopathological abnormality.