Patients
PBMC of CD patients with small intestinal manifestation and UC patients
with either active disease (defined by Harvey Bradshaw Index (HBI)) or
remission (defined by HBI; pMayo) 13,14 were analyzed.
Additionally, CeD patients on a GFD for at least one year, newly
diagnosed active CeD patients still exposed to gluten (aCeD), or
GFD-refractory CeD patients (Refr) were included. Moreover, healthy
first-degree relatives (FDR) on a regular diet without symptoms were
included. The diagnosis of CeD was based on the presence of tTG
antibodies in the serum and characteristic histopathological features in
duodenal biopsies (Marsh score >1). Refractory celiac
disease diagnosis was based on the presence of a Marsh III enteropathy
and clinical malabsorption in spite of consumption of a gluten-free diet
for at least one year. Clonality analysis as done by PCR of the CDR3
region of the TCR was performed. Detection of a clonal T-cell population
and aberrant lymphocytes by immune phenotyping of duodenal tissue
allowed for diagnosis of Refr. type II. All other Refr. cases were
diagnosed as RCD type I15. HLA-DQ status could not be
determined for IBD patients and controls. As additional non-intestinal
inflammatory control group PBMC from rheumatoid arthritis (RA) patients
were analyzed.