CD44 and CXCL9 serum protein levels predict the risk of clinically significant allograft rejection after liver transplantation.

The diagnosis of acute cellular rejection (ACR) after liver transplantation is based on histological analysis of biopsies because noninvasive biomarkers for allograft rejection are not yet established for clinical routines. CD31, CD44, and chemokine (C-X-C motif) ligand (CXCL) 9 have previously been described as biomarkers for cross-organ allograft rejection. Here, we assessed the predictive and diagnostic value of these proteins as serum biomarkers for clinically significant ACR in the first 6 months after liver transplantation in a prospective study. The protein levels were measured in 94 patients immediately before transplantation, at postoperative days (PODs) 1, 3, 7, and 14 and when biopsies were performed during episodes of biochemical graft dysfunction. The CD44 serum protein levels were significantly lower at POD 1 in patients who experienced histologically proven ACR in the follow-up compared with patients without ACR (P < 0.001). CXCL9 was significantly higher before transplantation (P = 0.049) and at POD 1 (P < 0.001) in these patients. Low CD44 values (cutoff, <200.5 ng/mL) or high CXCL9 values (cutoff, >2.7 ng/mL) at POD 1 differentiated between rejection and no rejection with a sensitivity of 88% or 60% and a specificity of 61% or 79%, respectively. The combination of both biomarker cutoffs at POD 1 had a positive predictive value of 91% and a negative predictive value of 67% for clinically significant ACR. Moreover, CD44 was significantly lower at the time of ACR (P < 0.001) and differentiated the rejection group from patients with graft dysfunction due to other reasons. Our results suggest that CD44 and CXCL9 may serve as predictive biomarkers to identify liver allograft recipients at risk for clinically significant ACR.

[Comparison between navigated and conventional percutaneous screw fixation of non-displaced scaphoid fractures]. / Vergleich der navigierten und konventionellen perkutanen Verschraubung undislozierter Kahnbeinfrakturen.

BACKGROUND: Incorrect screw placement and penetration in screw fixation of scaphoid fractures are found in 5 to 30 %. Therefore, optimizing of screw placement is desirable, especially because an exact central position of the screw in the proximal fragment leads to a significant higher stability as a more peripheral position. PATIENTS UND METHODS: 36 patients with an acute non-displaced scaphoid fracture were included in this randomized prospective study. 18 patients underwent navigated, the other 18 conventional percutaneous screw fixation of an acute non-displaced scaphoid fracture through a dorsal approach. Operation time and x-ray dose were measured. In both groups the position of the screw in the scaphoid was calculated on CT scans and compared with each other. Clinically, 17 patients with navigated and 11 with conventional percutaneous screw fixation with an average age of 52 resp. 43.2 years were available for follow-up examination including Krimmer- and DASH-score. RESULTS: All scaphoids healed within an adequate time. Two cases of navigated screw fixation have been converted to conventional percutaneous screw fixation. The average operation time in the navigated group was 83.2 minutes, in the conventional group 42.1 minutes. X-ray dose measured 106,5 ± 19,9cGy/cm2 in the navigated group and 45,6 ± 8,0cGy/cm2 in the conventional group. Screw penetration using an intraosseous compression screw (HSC) was observed in 5 conventionally fixed scaphoids, 4 distally (2,27 ± 1,47 mm), 1 proximally. In the navigated group there were 11 screw penetrations, 4 proximally (2,01 ± 0,81 mm) and distally (1,21 ± 0,64 mm), 3 distally (1,18 ± 0,44 mm), and 4 proximally (1,61 ± 0,57 mm). Axial screw position was more accurate in the conventional group. The 17 navigated patients averaged a Krimmer-Score of 83.6 and a DASH-score of 5,6 points at follow-up. The 11 conventional treated patients averaged a Krimmer-Score of 95 and a DASH-score of 8.0 points at follow-up. CONCLUSION: In this study navigated screw fixation of acute non-displaced scaphoid fractures was not superior to conventional percutaneous screw fixation, neither for screw position, screw penetration nor with respect to the clinical outcome.