A novel A20 (TNFAIP3) antibody (Ber-A20) can be used to detect unmutated A20 by immunohistology.

AIMS: A20 (TNFAIP3) is a nuclear factor-κB (NF-κB)-inducible component of tumour necrosis factor and Toll-like receptor intracellular signal transduction. It negatively regulates NF-κB, and has been identified as a tumour suppressor. Several studies have described A20 inactivation by deletion of the A20 locus at 6q23, inactivating mutations, and/or methylation of the A20 promoter in various lymphoma entities. METHODS AND RESULTS: We generated a monoclonal antibody against the C-terminus of A20 (Ber-A20) and investigated full-length A20 expression of normal lymphoid tissue and lymphomas for the first time. We identified loss of A20 expression in tumour cells of 24% of classical Hodgkin lymphoma, 27% of diffuse large B-cell lymphoma, 20% of chronic lymphocytic leukaemia, 19% of follicular lymphoma, 13% of mantle cell lymphoma and 8% of primary mediastinal B-cell lymphoma cases by immunohistology. Loss of A20 expression rarely occurred in T-cell non-Hodgkin lymphoma. CONCLUSIONS: Our data are in agreement with cytogenetic and molecular analyses. Among 21 cases of ocular adnexal marginal zone lymphomas with known A20 mutation status, we detected complete absence of A20 expression, whereas cases with wild-type A20 were weakly A20-positive. We demonstrate that A20 loss can be detected by immunohistology with a sensitivity similar to that of complex molecular and genetic methods.

Urinary calprotectin and the distinction between prerenal and intrinsic acute kidney injury.

BACKGROUND AND OBJECTIVES: To date there is no reliable marker for the differentiation of prerenal and intrinsic acute kidney injury (AKI). We investigated whether urinary calprotectin, a mediator protein of the innate immune system, may serve as a diagnostic marker in AKI. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: This was a cross-sectional study with 101 subjects including 86 patients with AKI (34 prerenal, 52 intrinsic including 23 patients with urinary tract infection) and 15 healthy controls. Assessment of urinary calprotectin concentration was by ELISA and immunohistochemistry of kidney biopsy specimens using a calprotectin antibody. Inclusion criteria were: admission to hospital for AKI stage 1 to 3 (Acute Kidney Injury Network); exclusion criteria were: prior renal transplantation and obstructive uropathy. RESULTS: Median urinary calprotectin was 60.7 times higher in intrinsic AKI (1692 ng/ml) than in prerenal AKI (28 ng/ml, p <0.01). Urinary calprotectin in prerenal disease was not significantly different from healthy controls (45 ng/ml, p = 0.25). Receiver operating curve curve analysis revealed a high accuracy of calprotectin (area under the curve, 0.97) in predicting intrinsic AKI. A cutoff level of 300 ng/ml provided a sensitivity of 92.3% and a specificity of 97.1%. Calculating urinary calprotectin/creatinine ratios did not lead to a further increase of accuracy. Immunostainings of kidney biopsies were positive for calprotectin in intrinsic AKI and negative in prerenal AKI. CONCLUSIONS: Accuracy of urinary calprotectin in the differential diagnosis of AKI is high. Whereas calprotectin levels in prerenal disease are comparable with healthy controls, intrinsic AKI leads to highly increased calprotectin concentrations.

Surveillance colonoscopy in patients with inflammatory bowel disease: comparison of random biopsy vs. targeted biopsy protocols.

BACKGROUND: Endoscopic surveillance in patients with long-standing inflammatory bowel disease (IBD) improves early detection of intraepithelial neoplasia (IEN). We aimed to compare three different endoscopic surveillance strategies in the detection of IEN. METHODS: One hundred fifty surveillance colonoscopies (ulcerative colitis, UC n = 141; Crohn's disease, CD n = 9) were carried out. Random quadrant biopsies were taken (group I, n = 50). Chromoendoscopy with indigo carmine was performed and subsequently quadrant biopsies were collected (group II, n = 50). Patients in group III (n = 50) underwent confocal endomicroscopy (CEM), and CEM-guided as well as random quadrant biopsies were taken (group III, n = 50). The findings of CEM were correlated to conventional histology. Patients with high-grade IEN underwent surgery or strict follow-up by patients' request. RESULTS: In group I (1531 biopsies), no IEN was detected by histology. In group II (1,811 biopsies), chromoendoscopy-guided biopsies revealed high-grade IEN in two patients (4% detection rate). In four patients of group III (1477 biopsies), areas with high-grade IEN were clearly visible by CEM and confirmed by histology (8% detection rate, p < 0.05). Of six patients with high-grade IEN, five patients underwent proctocolectomy. Colorectal cancer was detected in one out of five patients. CONCLUSION: Targeted biopsy protocols guided by either chromoendoscopy or CEM led to higher detection rates of IEN and are thus mandatory for surveillance colonoscopies in patients with long-standing UC. Random biopsy protocols should be replaced by chromoendoscopy-guided protocols.

Differences in the T-bet and GATA-3 expression patterns between lymphocytic colitis and coeliac disease.

Lymphocytic colitis (LC) is a disease of unknown aetiology. Among other pathogenetic possibilities, an abnormal reaction to a luminal antigen has been discussed. To clarify this fact, we characterized the inflammatory infiltrate in LC and compared it with the Th1 response-related coeliac disease (CD). Biopsies from 10 LC and 10 CD patients were analyzed by immunohistochemistry for detection of T-bet, the master regulator of Th1 response and its antagonist GATA-3 in T cells employing double labellings. In LC, 10-20% of intraepithelial lymphocytes (IEL) expressed GATA-3 and the remaining T-bet, whereas in CD, all IEL were T-bet-positive. The T cells in the lamina propria of LC (65-70% CD4+; 30-35% CD8+) showed a mixed expression pattern of T-bet and GATA-3. The majority of the CD4+ T cells were GATA-3+, while T-bet and GATA-3 were expressed at a similar frequency by the CD8+ T cells. Most of the T cells in the lamina propria of CD specimens were CD4+, showing a predominant T-bet expression. Also, most of the CD8+ lamina propria T cells in CD were T-bet+. We conclude that in contrast to CD, which exhibits immunophenotypical features of a Th1-response, LC shows features of a mixed Th1/Th2 immune response.

Noninvasive evaluation of renal allograft fibrosis by transient elastography--a pilot study.

Chronic allograft injury (CAI) is the most common cause of graft failure after the first year of transplantation. To date, only protocol biopsies can reveal subclinical disease. Transient elastography (TE) is a novel noninvasive technique that has demonstrated high reliability in the assessment of liver fibrosis. This study evaluates the feasibility of TE for the assessment of renal allograft fibrosis. Fifty-seven patients underwent TE by the FibroScan device. Biopsies were performed in 20 patients. Measurement of parenchymal stiffness by TE was successful in 55 of 57 patients (96.5%). Stiffness was significantly correlated to the extent of interstitial fibrosis (Pearson r: 0.67, P: 0.002, R(2): 0.45) and inversely related to estimated glomerular filtration rate (eGFR) (Pearson r: -0.47, P: 0.0003, R(2): 0.22). Stiffness values of patients with an eGFR >50 ml/min were significantly lower than in patients with an eGFR < or = 50 ml/min (22.2 +/- 11.0 vs. 37.1 +/- 14.2 kPa, P: 0.0005). The stiffness values of CAI Banff grades 0-1 differed significantly from grade 2 (P: 0.008) and grade 3 (P: 0.046). Parenchymal stiffness measured by TE reflects interstitial fibrosis in kidney allografts. A longitudinal assessment of parenchymal stiffness might be a powerful tool to identify patients with CAI who benefit from biopsy and consequent adaptation of the immunosuppressive regime.

Differential expression of TRAF1 aids in the distinction of cutaneous CD30-positive lymphoproliferations.

Lymphomatoid papulosis (LyP), primary cutaneous anaplastic large T-cell lymphoma (cALCL), and cutaneous infiltrates of systemic anaplastic large cell lymphoma (sALCL) are CD30-positive lymphoproliferative disorders of the skin that overlap clinically, histopathologically, immunophenotypically, and genetically but differ considerably in their prognosis. In particular, lesions of LyP regress spontaneously, whereas those of cALCL and sALCL persist and may progress and spread to extracutaneous sites. In contrast to patients with cALCL, LyP patients do not benefit from an aggressive radio- and/or chemotherapeutic approach. We generated a novel tumor necrosis factor receptor (TNFR)-associated factor 1 (TRAF1) antibody that recognizes a formalin-resistant epitope (Ber-TRAF1A) and investigated the expression of TRAF1, an intracellular component of TNFR signaling, in LyP and ALCL. We could show a strong TRAF1 expression in the tumor cells of most LyP cases (42/49, 84%). In contrast, tumor cells of primary and secondary cALCL revealed TRAF1 expression in only a few cases (3/41, 7%) as shown for sALCL without skin manifestation. The data indicate that TRAF1 expression reliably distinguishes LyP from primary or secondary cALCL. This might be of crucial diagnostic importance and has a strong impact on the treatment decision for patients with cALCL and LyP.