Unravelling the role of SOCS3 in aortic valve stenosis

Background

Calcific aortic valve stenosis (CAVD) is the most prevalent heart valve disease worldwide and, in advanced stages, leads to clinical deterioration and poor prognosis. Until now, no medical treatment is available. Thought to be a merely degenerative disease, we now know that disease initiation and progression are actively regulated by immune cell infiltration, chronic inflammation, osteogenic differentiation of valvular interstitial cells (VIC) and endothelial-to-mesenchymal transition (EndMT) of valvular endothelial cells (VEC). Suppressor of Cytokine Signaling 3 (SOCS3) is known to be a key regulator of inflammation. It promotes the polarisation of macrophages to an inflammatory phenotype and thus, contributes to disease progression in atherosclerosis. In CAVD, not only inflammation but also heterotopic bone formation leads to the thickening and obstruction of the aortic valve cusps and as SOCS3 is one of the main regulators of physiological bone formation, it could play a critical role in the progression of CAVD.

Purpose

We hypothesize that SOCS3 plays a crucial role during calcification of the aortic valve through regulation of EndMT, calcification of valvular interstitial cells and macrophage polarization.

Methods and results

In initial screening experiments, we investigated SOCS3-protein expression in explanted human aortic valves from patients undergoing surgical aortic valve replacement. SOCS3 is expressed in both stenotic and non-stenotic valve tissues. Immunofluorescence-staining of human aortic valves shows the co-localisation of SOCS3 with the interstitial cell-marker Vimentin and SOCS1, which is known to regulate macrophage-polarisation together with SOCS3 (Fig. 1). Staining of the macrophage-marker CD68 revealed its co-localisation with calcified areas of the aortic valve cusp. We validated our findings in our in vitro model of VIC calcification using two different calcifying conditions. Upregulation of RUNX2 and BMP2 verified successful osteogenic differentiation of VICs. During osteogenic differentiation for 7 days, SOCS3 and SOCS1 are significantly upregulated (Fig. 2A).

We were able to induce EndMT by stimulating VEC with either TNFα or TGFβ/IL1β in vitro. We show that EndMT leads to the loss of endothelial cell markers like eNOS and VWF and to an upregulation of interstitial cell markers (such as Vimentin and α-SMA) and markers of EndMT (SNAI2). During EndMT, we were also able to observe a significant upregulation of SOCS1 and SOCS3 after 7 days (Fig. 2B). Ongoing knockdown experiments will help to elucidate the role of SOCS1 and SOCS3 during initiation and progression of CAVD.

Conclusion

We aim towards a better understanding of SOCS3 and its role in inflammation and calcification as hallmarks of the pathogenesis of CAVD. Since Zoledronic acid has been shown to induce a decreased expression of SOCS3 in macrophages, this might present as a possible treatment strategy to target SOCS3 therapeutically.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Deutsche Forschungsgemeinschaft

[Machine perfusion for conditioning liver and kidneys before transplantation]

Machine perfusion will become established as the standard of care for solid organ transplantation in the near future. Ongoing studies are investigating the appropriate perfusion algorithms for each specific organ. Although it is neither proven which perfusion principle nor type of device is superior, it has already been sufficiently shown that the increasing number of marginal organs that are currently transplanted in Germany would benefit from machine perfusion for conditioning before transplantation. The addition of hypothermic and normothermic perfusion sequences opens up the possibility of conditioning of previously damaged organs as well as viability testing. Overall, machine perfusion increases the safety for the recipient and can counteract the increasingly more difficult scenario of working hour restrictions because solid organ transplantations in the future will be plannable and carried out during the day.

Left-Sided Living Kidney Donation Leads to Transiently Reduced Adrenocortical Responsiveness

Living kidney donation is safe and established, but can lead to long-term complications such as chronic fatigue. Since the adrenal vein is usually transected during left-sided donor nephrectomy-which is not necessary on the right-we hypothesized that venous congestion might lead to an impairment of adrenal function, offering a possible explanation. In this prospective open label, monocentric cohort study, adrenal function was compared in left- and right-sided living kidney donors. The primary endpoint was plasma cortisol response to low-dose adrenocorticotropic hormone (ACTH) stimulation. Secondary endpoints included plasma renin and ACTH concentration as well as adrenal volume in response to donor nephrectomy. A total of 30 healthy donors-20 left- and 10 right-sided donations-were included. On postoperative day 1, response to low-dose ACTH stimulation was intact, but significantly lower after left-sided donor nephrectomy. After 28 days, adrenal responsiveness to ACTH stimulation did not differ any longer. Magnetic resonance imaging volumetry showed no significant adrenal volume change over 4 weeks, neither after left- nor after right-sided nephrectomy. In conclusion, left-sided living kidney donation entails a transiently reduced adrenocortical responsiveness, which returns to baseline after 28 days.

Liver transplantation for hilar cholangiocarcinoma: a German survey

BACKGROUND

The present study reports a German survey addressing outcomes in nonselected historical series of liver transplantation (OLT) for hilar cholangiocarcinoma (HL).

PATIENTS AND METHODS

We sent to all 25 German transplant centers performing OLT a survey that addressed (1) the number of OLTs for HL and the period during which they were performed; (2) the incidence of HL diagnosed prior to OLT/rate of incidental HL (for example, in primary sclerosing cholangitis); (3) tumor stages according to Union Internationale Centre le Cancer; (4) patient survival; and (5) tumor recurrence rate.

RESULTS

Eighty percent of centers responded, reporting 47 patients who were transplanted for HL. Tumors were classified as pT2 (25%), pT3 (73%), or pT4 (2%). HL was diagnosed incidentally in 10% of cases. A primary diagnosis of PSC was observed in 16% of patients. Overall median survival was 35.5 months. When in-hospital mortality (n = 12) was excluded, the median survival was 45.4 months, corresponding to 3- and 5-year survival rates of 42% and 31%, versus 31% and 22% when in-hospital mortality was included. HL recurred in 34% of cases. Three- and 5-year survivals for the 15 patients transplanted since 1998 was 57% and 48%, respectively. Median survival ranged from 20 to 42 months based on the time period (P = .014).

CONCLUSIONS

The acceptable overall survival, the improved results after careful patient selection since 1998, and the encouraging outcomes from recent studies all suggest that OLT may be a potential treatment for selected cases of HL. Prospective multicenter randomized studies with strict selection criteria and multimodal treatments seem necessary.

Liver transplantation for hilar cholangiocarcinoma: a German survey

BACKGROUND

The present study reports a German survey addressing outcomes in nonselected historical series of liver transplantation (OLT) for hilar cholangiocarcinoma (HL).

PATIENTS AND METHODS

We sent to all 25 German transplant centers performing OLT a survey that addressed (1) the number of OLTs for HL and the period during which they were performed; (2) the incidence of HL diagnosed prior to OLT/rate of incidental HL (for example, in primary sclerosing cholangitis); (3) tumor stages according to Union Internationale Centre le Cancer; (4) patient survival; and (5) tumor recurrence rate.

RESULTS

Eighty percent of centers responded, reporting 47 patients who were transplanted for HL. Tumors were classified as pT2 (25%), pT3 (73%), or pT4 (2%). HL was diagnosed incidentally in 10% of cases. A primary diagnosis of PSC was observed in 16% of patients. Overall median survival was 35.5 months. When in-hospital mortality (n = 12) was excluded, the median survival was 45.4 months, corresponding to 3- and 5-year survival rates of 42% and 31%, versus 31% and 22% when in-hospital mortality was included. HL recurred in 34% of cases. Three- and 5-year survivals for the 15 patients transplanted since 1998 was 57% and 48%, respectively. Median survival ranged from 20 to 42 months based on the time period (P = .014).

CONCLUSIONS

The acceptable overall survival, the improved results after careful patient selection since 1998, and the encouraging outcomes from recent studies all suggest that OLT may be a potential treatment for selected cases of HL. Prospective multicenter randomized studies with strict selection criteria and multimodal treatments seem necessary.

Kidney Transplantation Using Donors With History of Diabetes and Hypertension

PURPOSE

Due to the persistant organ shortage for kidney transplantation, donor selection has changed in the past years. Although hypertension and diabetes mellitus are known to be risk factors for renal insufficiency, kidneys from donors with these diagnoses in their history have been accepted for kidney transplantation even with an increased risk of poor graft function. Herein we have reported our experience with kidney transplantation using grafts from donors with both, a history of type II diabetes and hypertension.

METHODS

Between 2000 and 2005, ten patients were grafted using donors with history of type II diabetes mellitus and hypertension. Mean donor age was 58 +/- 7.5 years and recipient age, 52.2 +/- 15.7 years. Mean HLA mismatch was 0.8 (A); 1.2 (B) and 0.9 (DR). Cold ischemia time was 17.4 +/- 4.1 hours. Immunosuppression was based on CyA (n = 7), tacrolimus (n = 2) or sirolimus (n = 1).

RESULTS

Six patients (60%) showed good initial function, and four (40%) had delayed graft function (DGF). One patient died at ten weeks due to multiorgan failure. Two (20%) biopsy-proven rejections were diagnosed, one of which was resistant to therapy. Six months after kidney transplantation, 7 (77%, n = 9) showed good graft function (creatinine 1.3 to 2.4 mg/dL), but one patient displayed long-lasting DGF with poor function.

CONCLUSION

Grafts from donors with a history of diabetes mellitus and hypertension are suitable for kidney transplantation. Elevated rate of DGF (40%) would justify allocation of these organs to local transplant centers to shorten ischemia time and thereby reduce DGF and achieve better long-term results. Identification and detailed evaluation of these donors prior to allocation (eg, HbAlc, biopsy) may help transplant centers to accept these kidneys.

Living Donor Kidney Transplantation From the Elderly Donor

PURPOSE

The organ shortage has led to increasing acceptance of living donation in all transplant centers. Although the risk of impaired long-term outcome seems to be greater using elderly donors, these organs are not generally refused for transplantation. We report our experience with 25 living donor kidney transplantations from donors older than 60 years.

METHODS

Between 1995 and 2004, 124 living donor procedures were performed in our center from 83 related and 41 unrelated donors. Twenty-five donors (19 female, 6 male) were 60 years or older (mean, 65.3 +/- 3.9 years). The recipient included (10 females and 15 males) showed a higher degree of variance in age (46.1 +/- 14.6 years). The immunosuppressive protocol was cyclosporine (CyA)-based regimen in related cases and tacrolimus-based in unrelated cases.

RESULTS

We transplanted 16 left and 9 right kidneys from older donors. The mean cold ischemia time was 171 +/- 64 minutes with a second warm ischemia time of 24 +/- 6 minutes. Severe arteriosclerosis made vascular reconstruction by graft interposition necessary in two recipients. The acute rejection rate was 20%. Two patients (8%) required dialysis in the early postoperative course, whereas initial function was excellent in 22 patients (88%). The mean serum creatinine concentration after 12 months was 1.6 +/- 0.3 mg/dL (n = 24) and 2.0 +/- 0.7 mg/dL (n = 16) at 4 years. In comparison, the mean creatinine concentration after 4 years in donors under 60 years was 1.6 +/- 0.9 mg/dL. Our analysis showed no significant difference in long-term graft function comparing young versus old donors in the setting of living donor transplants.

CONCLUSION

Using living donors older than 60 years for transplantation is a feasible and safe option. The difference in long-term creatinine between young and old donors was not significant.

Retrieval of abdominal organs for transplantation

BACKGROUND

Organ retrieval and donor management are not yet standardized. Different transplant centres apply various techniques, such as single or dual organ perfusion, dissection in the cold or warm, and single or en bloc organ removal. These different approaches may cause inconvenience, especially when more than one organ retrieval team is involved.

METHODS

Cochrane Library, Medline and PubMed were searched for publications on multiorgan donor/donation, retrieval technique and procurement. Levels of evidence and grades of recommendation were evaluated based on current advice from the Oxford Centre for Evidence-Based Medicine.

RESULTS

Multiorgan donation itself does not compromise the outcome of individual organ transplants. Dissection of abdominal organs for transplantation is best performed after cold perfusion. Abdominal organs should be removed rapidly, en bloc, and separated during back-table dissection in the cold, particularly if pancreas or intestine is included. Perfusion itself should be carried out after single cannulation of the aorta with an increased pressure.

CONCLUSION

Although the literature on organ retrieval is extensive, the level of evidence provided is mainly low. Nevertheless, optimized donor treatment and organ retrieval should increase the number and quality of cadaveric donor organs and improve graft function and survival.

Living donor kidney transplantation: impact of differentiated immunosuppressive regimen

INTRODUCTION

Recipients of related (R) and unrelated (NR) living donor kidney transplantations (LDKTX) receive immunosuppressive (IS) therapy 5 days in advance in order to achieve low rates of acute rejection episodes. We herein report the different IS regimens for R and NR transplants as well as acute rejection and primary function rates.

METHODS

Ninety-five LDKTX (69% R, 31% NR) were performed with mean cold ischemia time (CIT) of 145 +/- 32 minutes. In R-LDKTX mean age of recipients was 31 +/- 12.5 years. This cohort included 41 men and 25 women whose mean age was 50 +/- 11.1 years. The therapeutic regimen for R-LDKTX included CyA/MMF/prednisone; for NR-LDKTX, FK/MMF/prednisone. Among the recipients of NR grafts the mean recipient age was 51 +/- 8.5 years. This cohort included 23 men and 6 women whose donor mean age was 50 +/- 8.8 years. The mean HLA mismatch among R-LDKTX (2.3) was significantly less than that in the NR-LDKTX cohort (3.51).

RESULTS

At a mean follow-up of 35 months, 94.7% of grafts were functioning. DGF was seen in only one recipient (1%). Three grafts were lost due to acute (R) or chronic (NR) rejection or to multiorgan failures. Two recipients died with functioning grafts. Biopsy-proven rejection episodes were observed in 17.2% of NR-LDKTX and 9% of R-LDKTX. In R-LDKTX 50% of rejection episodes were corticoid-sensitive, while 33% needed ATG, and 16% were treated by a switch to FK. In NR-LDKTX 20% of rejections were corticoid-sensitive, 40% needed ATG, and 40% were treated with rapamycin rescue therapy.

CONCLUSION

Although HLA mismatching is significantly different between R- and NR-LDKTX, no difference in outcome was observed, which may be due to the specific therapeutic regimen and short CIT.

Complications due to gallstones lost during laparoscopic cholecystectomy

BACKGROUND

The aim of this study was to identify predisposing factors for complications after gallstone spillage during laparoscopic cholecystectomy (LC).

METHODS

Papers derived from Medline search and papers from reference lists within these papers were studied. Ninety-one reports on complications caused by lost gallstones published between 1991 and 1998 were analyzed. These patients were compared with cases in published series on LC in general.

RESULTS

Gallbladder perforation (20%) and stone spillage (9%) were the two most common complications of LC which occurred during the dissection (75%) and removal (25%) of the gallbladder. Predisposing factors for developing complications after stone spillage were: older age, male sex, acute cholecystitis, spillage of pigment stones, number of stones (>15) or size of the stone (Ø > 1.5 cm), and perihepatic localization of lost stones. CT-scan and ultrasound examination proved best for the recognition of complications caused by lost stones. Explorative laparotomy and surgical removal of the stones was the most frequently used therapy.

CONCLUSIONS

Gallbladder perforation and stone spillage might cause hazardous complications. In cases with loss of numerous or large pigment stones which cannot be retrieved by laparoscopy, intraoperative conversion to open surgery can be justified.

Analysis of serum CYFRA 21-1 concentrations in patients with esophageal cancer

BACKGROUND

This study was conducted to determine the use of CYFRA 21-1 for patients suffering from esophageal carcinoma.

MATERIALS AND METHODS

50 patients with malignant, 50 patients with benign esophageal lesions, 50 healthy persons and 50 patients with benign lung disease were tested for CYFRA 21-1, CEA, CA 72-4 and SCC-antigen serum concentrations. The patients with esophageal carcinoma underwent follow-up analysis for one year.

RESULTS

CYFRA 21-1 (cut-off: 1.40 ng/ml) showed a sensitivity for esophageal carcinoma of 46% at a specificity of 89.3%. There was a tendency for higher serum CYFRA 21-1 concentrations in advanced T-stages. Correlations of CYFRA 21-1 with N or M stages could not be observed. The postoperative course, in terms of survival and tumor free survival showed significant correlation to pre-operative CYFRA 21-1 concentrations. Adjuvant therapy could be monitored by CYFRA 21-1 as well. Clinical tumor recurrence was preceded by CYFRA 21-1 elevation by 3.4 months.

CONCLUSIONS

We recommend the use of CYFRA 21-1 in cases of esophageal carcinoma, especially in cases of squamous cell carcinoma.

CYFRA 21-1 serum analysis in patients with esophageal cancer

This study was conducted to determine a potential use of CYFRA 21-1 in patients suffering from carcinoma of the esophagus. CYFRA 21-1 serum concentrations of 50 patients with histologically proven malignant lesion of the esophagus were compared with 50 healthy persons, 50 patients with benign esophageal disease, and 50 patients with benign lung disease. Additional analysis of serum carcinoembryonic antigen, CA 72-4, and squamous cell carcinoma-antigen serum concentrations were performed. The patients with esophageal carcinoma underwent follow-up tumor marker examinations every three months for 1 year. Analysis to detect statistically significant differences was conducted to estimate a cutoff and to evaluate tumor entity, tumor stage, survival, and tumor-free survival. CYFRA 21-1 at a cutoff of 1.40 ng/ml showed an overall sensitivity to esophageal carcinoma of 36% (45.5% to squamous cell carcinoma, 17.6% to adenocarcinoma) at a specificity of 97.3%. CYFRA 21-1 concentrations showed a tendency to higher serum levels depending on local tumor burden. A correlation of CYFRA 21-1 with various N- or M-stage disease was not observed. Postoperative development in terms of survival and tumor-free survival showed significant correlation to preoperative CYFRA 21-1 concentrations. Clinical tumor recurrence was preceded by CY-FRA 21-1 elevation by 3.4 months. For prognosis and follow-up, this marker is justified for additional analysis in a larger series of patients suffering from carcinoma of the esophagus.