Indirect immunofluorescence for of anti-jejunum antibody detection in celiac disease: Comparison among different antigenic substrates

Background Although anti-endomysium antibodies (EmA) are the most reliable serological markers of celiac disease (CD), there is a need for low-cost me thods for screening programs, as clinically silent disease is increasingly recognized. Aim. To evaluate the suitability of monkey, rat and rabbit jejunum as a sub strate for the determination of anti-jejunun antibodies (JAB) in CD. Methods. JAB of IgA class were detected by indirect immunofluorescence on f rozen sections of jejunum from monkeys, white rats and domestic rabbits. Se ra from 61 untreated adults with biopsy-proven CD and EmA positivity in 57 out of 61 entered the study as true positives, while sera from 60 controls were considered as true negatives. Results. The sections of monkey jejunum showed the characteristic pattern o f elongated villous fluorescence, a ring-like positivity of the cryptal bas ement membrane, an endomysium-like fluorescence along the smooth muscle lay ers in the tunica muscolaris, while pericryptal fluorescence was not so evi dent on rat and rabbit jejunum. As compared to EmA positivity, the prevalen ce of JAB on monkey, rat and rabbit tissues was respectively 57/57, 54/57, 52/57. Two sera among 4 Ema negatives proved positive for JAB. No false pos itivity resulted from EmA and JAB on monkey jejunum, while a lower specific ity was found for JAB on rat and rabbit substrates. Conclusions. Although monkey, rat and rabbit small intestine appeared to be a suitable alternative substrate for determination of IgA-JAB, because of its lower cost and higher availability, it cannot replace monkey oesophagus , and he recommended for wide use.