KRAS/GNAS-testing by highly sensitive deep targeted next generation sequencing improves the endoscopic ultrasound-guided workup of suspected mucinous neoplasms of the pancreas.

Pancreatic cysts or dilated pancreatic ducts are often found by cross-sectional imaging, but only mucinous lesions can become malignant. Therefore, distinction between mucinous and non-mucinous lesions is crucial for adequate patient management. We performed a prospective study including targeted next generation sequencing (NGS) of cell-free DNA in the diagnostic endoscopic ultrasound (EUS)-guided workup. Pancreatic cyst(s) or main duct fluid obtained by EUS-guided FNA was analysed by carcinoembryonic antigen (CEA), cytology and deep targeted NGS of 14 known gastrointestinal cancer genes (AKT1, BRAF, CTNNB1, EGFR, ERBB2, FBXW7, GNAS, KRAS, MAP2K1, NRAS, PIK3CA, SMAD4, TP53, APC) with a limit of detection down to variant allele frequency of 0.01%. Results were correlated to histopathology and clinical follow-up. One hundred and thirteen patients with pancreatic cyst(s) and/or a dilated pancreatic main duct (≥5 mm) were screened. Sixty-six patients had to be excluded, mainly due to inoperability or small cyst size (≤10 mm). Forty-seven patients were enrolled for further analysis. A final diagnosis was available in 27 cases including 8 negative controls. In 43/47 (91.5%) of patients a KRAS- and/or GNAS-mutation was diagnosed by NGS. 27.0% of the KRAS-mutated and 10.0% of the GNAS-mutated lesions harbored multiple mutations. KRAS/GNAS-testing by NGS, cytology, and CEA had a sensitivity and specificity of 94.7/100%, 38.1/100%, and 42.1/75.0%, respectively. KRAS/GNAS-testing was significantly superior to CEA (P = .0209) and cytology (P = .0016). In conclusion, KRAS/GNAS-testing by deep targeted NGS is a suitable method to distinguish mucinous from non-mucinous pancreatic lesions, suggesting its usage as a single diagnostic test. Results must be confirmed in a larger cohort.

Color doppler ultrasonography in the diagnostic evaluation of renal allografts.

Color Doppler ultrasonography of large allograft vessels and renal parenchyma is established firmly in the diagnosis of renal allograft perfusion. While conventional color Doppler ultrasonography has proven itself to be an indispensable, rapid, highly valid and practicable method, e.g. in the diagnosis of allograft artery stenosis or allograft vein thrombosis, the diagnostic usefulness of this method with regard to allograft perfusion is considerably limited. With contrast-enhanced sonography, a simple and readily implementable method that enables the early diagnosis of chronic allograft nephropathy is now available. The timely diagnosis of vascular damage prior to a rise in S-creatinine offers the possibility of early therapeutic intervention and thus at least the potential for the improvement of allograft survival.

Real-time contrast-enhanced sonography in renal transplant recipients.

Conventional colour Doppler ultrasonography (CDUS) is a well-established and the most frequently used imaging procedure to diagnose kidney allograft dysfunction. Unfortunately, this technique is limited to the estimation of the allograft perfusion in large arteries. Early diagnosis of vascular damage, i.e., chronic allograft nephropathy is essential for an early therapeutic intervention. CDUS is still limited in interpreting vascular integrity. In contrast-enhanced sonography (CES) is a feasible technique for quantitative analysis of kidney perfusion and early diagnosis of biopsy proven chronic allograft nephropathy. CES does not provide only quantitative information on microvascular perfusion of the renal allografts but also represents improved diagnostic significance compared with CDUS for the detection of chronic allograft nephropathy.

Cyclosporin A toxicity of the renal allograft--a late complication and potentially reversible.

UNLABELLED: Cyclosporin A (CsA) has improved patient and organ graft survival, but the dichotomy of benefit and toxicity is still an issue. In a retrospective analysis of 392 renal transplant recipients we documented CsA nephrotoxicity (striped fibrosis, arteriolar wall hyalinosis) in 28 (7.1%) patients (23 male/5 female) in a follow-up of more than one year post transplantation. Median age at renal transplantation was 41 years (13-60) and the period between transplantation and graft biopsy was 42 months (12-122). Median CsA trough levels (ng/ml) at 12 months post transplantation, at time of graft biopsy and at last follow-up were: 114 (71-265), 130 (78-285), 66 (24-115). The following parameters were assessed at 12 months post transplantation, at time of biopsy and at last follow-up: s-creatinine (micromol/l), Doppler resistive index, systolic and diastolic blood pressure (mm Hg) and the number of antihypertensives. Median s-creatinine at 12 months post transplantation was 150.3 (94.6-247.5), at biopsy 225.4 (121.1-353.6) and at last follow-up 160.0 (106.1-247.5) (p < 0.001 for biopsy vs. last follow-up). Resistive index decreased from 0.70 (0.64-0.88) to 0.68 (0.51-0.84) (p < 0.005), systolic blood pressure from 137 (100-168) to 130 (105-144) (p < 0.05) and the number of patients with more than 4 antihypertensives from 10 to 6 between biopsy and last follow-up, with no acute rejection episodes after modification of immunosuppressive therapy (50% of previous CsA trough level and addition of azathioprine or mycophenolate mofetil). CONCLUSION: CsA nephrotoxicity occurs late after renal transplantation with increased systolic blood pressure and Doppler resistive index. Reduction of CsA improves renal function, reduces graft resistive index and systolic blood pressure.