Lipid disorders before and after successful liver transplantation.

INTRODUCTION: Liver transplantation (LTx) is the only successful treatment for end-stage liver disease. The results of liver transplantation depend not only on graft survival but may be also affected by superimposed cardiovascular morbidities. The aim of this retrospective study was to assess the prevalence of lipid disorders as one of the important cardiovascular risk factors in patients before and after successful LTx. MATERIAL AND METHODS: One hundred eleven patients who underwent liver transplantation because of liver cirrhosis and survived at least 2 years with functioning graft between November 2005 and May 2014 were included in this retrospective analysis. The mean age of the patients at the time of liver transplantation was 49.7±12.2 years. The prevalence of dyslipidemia was assessed before and two years after liver transplantation. This was analyzed in relation to the etiology of liver disease, including alcohol toxicity, viral or autoimmune diseases. RESULTS: The prevalence of hypertriglyceridemia before and after LTx was 13.5% and 40.5%, respectively (P<0.001). Similarly, hypercholesterolemia was noted in 17.1% and 51.4% respectively (P<0.001). The annual incidence of hypertriglyceridemia and hypercholesterolemia during the first two years after LTx was 16.2% and 20.7%, respectively. The prevalence of hypertriglyceridemia (18.5% vs 66.7%, P<0.001) and hypercholesterolemia (29.6% vs 70.0%, P=0.002) was significantly lower in patients with the autoimmune cause of liver cirrhosis in comparison to patients with the alcoholic liver disease. CONCLUSIONS: The prevalence of dyslipidemia is increased after liver transplantation. The prevalence of dyslipidemia may be related to the cause of liver injury before LTx.

Cardiovascular Risk Factors in Patients Before and After Successful Liver Transplantation.

BACKGROUND Liver transplantation (LTx) is useful in the treatment of end-stage liver disease. Outcomes of transplantation are dependent upon graft survival and can also be affected by superimposed cardiovascular morbidities. The present retrospective study was performed to assess the prevalence of cardiovascular risk factors before and after LTx. MATERIAL AND METHODS A retrospective review of 130 patients undergoing liver transplantation between October 2005 and April 2014 was completed. The mean age of the patients was 49.3±11.9 years. The prevalence of cardiovascular risk factors was assessed before and 2 years after transplantation. The prevalence of cardiovascular risk factors was assessed using a comparison based upon the etiologies of liver disease resulting in transplantation including alcohol, viral, and autoimmune processes using a chi-square analysis. RESULTS The prevalence of diabetes mellitus before and 2 years after liver transplantation (LTx) were 18% and 48% (P<0.001). Hypertension was documented in 24% of patients at baseline and 70% after 2 years of follow-up (P<0.001). The prevalence rates of diabetes mellitus before and 2 years after LTx were 18% and 48% (P<0.001). The prevalence of hypertriglyceridemia before and after LTx was 15% and 38%, respectively (P<0.001). Hypercholesterolemia was noted in 16% and 46%, respectively (P<0.001). Thirteen percent of patients before LTx and 18% after were obese (body mass index higher than 30 kg/m²). The annual incidence of diabetes mellitus, hypertension, hypertriglyceridemia, hypercholesterolemia, and obesity during the first 2 years after LTx was 15%, 23.5%, 15%, 18.5%, and 6%, respectively. Twenty-four percent of patients before and 10% after LTx admitted to tobacco use (P<0.001). The prevalence of diabetes (38% vs 67%, P=0.02), hypertriglyceridemia (19% vs 63%, P<0.001), hypercholesterolemia (28% vs 67%, P=0.002), and obesity (9% vs 33%, P=0.02) was lower in patients with an autoimmune cause of liver cirrhosis in comparison to patients with alcoholic disease. CONCLUSIONS The prevalence of hypertension and glucose and lipid metabolism abnormalities may increase in patients after liver transplantation. The prevalence of cardiovascular risk factors in patients after LTx may be related to the cause of liver injury before LTx.

Alternatives to endokeratoplasty: an attempt towards reducing global demand of human donor corneas.

The cornea is an anterior transparent tissue of the eye that enables the transmission of surrounding light to the back of the eye, which is essential for maintaining clear vision. Corneal endothelial diseases can lead to partial or total blindness; hence, surgical replacement of the diseased corneal tissue with a healthy cadaveric donor graft becomes necessary when the endothelium is damaged. Keratoplasties face a huge challenge due to a worldwide shortage in the supply of human donor corneas. Hence, alternative solutions such as cell or tissue engineering-based therapies have been investigated for reducing the global demand of donor corneas. This review aims at highlighting studies that have been successful at replacing partial or total endothelial keratoplasty.

The cornea is an important tissue, as it allows the transmission of surrounding light to the back of the eye. The posterior layer of the cornea is made up of hexagonal endothelial cells that help maintaining the required transparency. Corneal endothelial cells do not have a natural regenerative capacity; therefore, if damaged, they must be replaced by healthy donor tissue. It is difficult to obtain human donor corneas; hence, researchers have attempted to grow endothelial cells using specific drugs that allow these cells to grow in the lab. In this review, we highlight the application of lab-grown cells in animal and human studies with ongoing clinical trials of other drugs and techniques to replace the need of human donor tissues.

Ultra-thin DSAEK using an innovative artificial anterior chamber pressuriser: a proof-of-concept study.

PURPOSE: To report the impact of establishing and maintaining a high intracameral pressure (ICP) of 200 mmHg on UT-DSAEK graft preparation using an artificial anterior chamber pressuriser (ACP) control unit (Moria SA, Antony, France). METHOD: Retrospective laboratory and clinical study. Four paired donor corneas were mounted on an artificial anterior chamber and subjected to 70 mmHg ("low") and 200 mmHg ("high") ICP using an ACP system. The central corneal thinning rate was measured after 5 min using AS-OCT and the endothelial cell viability was analysed using trypan blue and live/dead staining following 70 mmHg and 200 mmHg ICP. Visual outcomes and complications in a clinical case series of nine patients with bullous keratopathy who underwent UT-DSAEK using 200 mmHg ICP during graft preparation are reported. RESULTS: Laboratory outcomes showed 2 ± 1% and 2 ± 2% dead cells following 70 mmHg and 200 mmHg ICP respectively. Percentage viability in the 70 mmHg group (52.94 ± 5.88%) was not found to be significantly different (p = 0.7) compared to the 200 mmHg group (59.14 ± 10.43%). The mean corneal thinning rate after applying 200 mmHg ICP was 27 ± 13 µm/min centrally (7.2%/min). In the clinical case series, two cases were combined with cataract surgery. Re-bubbling rate was 11%. At the last follow-up (259 ± 109 days), graft thickness was 83 ± 22 µm centrally, endothelial cell density was 1175 ± 566 cell/mm2 and the BCVA of 0.08 ± 0.12 logMAR was recorded with no episodes of rejection. CONCLUSION: ACP control unit for UT-DSAEK graft preparation helps in consistently obtaining UT-DSAEK grafts without compromising endothelial cell viability.

Preloaded Descemet Membrane Endothelial Keratoplasty Grafts With Endothelium Outward: A Cross-Country Validation Study of the DMEK Rapid Device.

PURPOSE: To validate the "Descemet membrane endothelial keratoplasty (DMEK) Rapid" device for the cross-country transportation of preloaded DMEK grafts preserved with endothelium outward. METHODS: DMEK grafts were stripped and loaded in the DMEK Rapid device with tissue culture medium (TCM) or transport medium (TM) with endothelium outward. The device was mounted in a 40-mL flask and preserved for 4 days on a rocker to simulate transportation (study A, n = 24) or shipped in the TM from Italy to the United Kingdom (study B, n = 9) and evaluated within 72 hours. All the tissues were stained with Alizarin red. Viability of the cells was checked postsimulations and posttransportation and was confirmed using live/dead staining. Expression of tight junction proteins was evaluated. RESULTS: In study A, the endothelial cell loss observed from the TCM group was 20.8% (±5.2) compared with 19.5% (±6.7) from the TM group (P = 0.41) after transport simulation. Alizarin red showed minimal uncovered areas in both groups. There were no statistical differences in viability between the TM (80.83%) and TCM groups (78.83%). In study B, 12.9% (±7.8) endothelial cell loss was observed after transporting the tissues from Italy to the United Kingdom with no significant difference between prestrip and posttransportation (P = 0.05). Alizarin red staining did not show any uncovered area. Live/dead analysis showed 85.16% cell viability after transportation. zonula occludens-1 (ZO-1) was expressed in all tissues. CONCLUSIONS: The DMEK Rapid device is safe for preloading and shipping DMEK grafts internationally with endothelium outward within 72 hours when preserved in the transport media.

The "Yogurt" Technique for Descemet Membrane Endothelial Keratoplasty Graft Preparation: A Novel Quick and Safe Method for Both Inexperienced and Senior Surgeons.

PURPOSE: To describe and evaluate the efficacy and safety of a novel technique to prepare Descemet membrane endothelial keratoplasty (DMEK) donor grafts using a newly designed partial-thickness hinge punch. METHODS: The novel punch has a circular guarded blade missing 1 clock hour, creating an uncut hinge on the donor cornea. In addition, 2 straight cuts are made by the punch perpendicular to the edge of trephination toward the trabecular meshwork in the hinge area. After the donor corneoscleral rim is positioned endothelial side up, a partial-thickness trephination is performed avoiding any rotational movements. Descemet membrane is lifted from Schwalbe line in the hinge area, and DMEK graft is peeled after desired marking without further preparation. RESULTS: Three surgeons of different experience levels on DMEK (senior/independent/fellow) initially applied the new technique in 18 research corneas, divided into equal groups. Two failures in graft preparation were noted, defined as radial tears extending ≥0.5 mm. The mean preparation time was 6.21 ± 1.45 minutes. No statistically significant differences were noted in success rate, duration, and endothelial cell loss (ECL) between surgeons (P > 0.05). ECL was evaluated as an average of 5 readings on randomly selected graft areas, not including graft periphery. Fifteen additional research corneas were stripped by 1 single user in an eye bank setting. No tissue loss was recorded, whereas ECL and mortality rate remained unaffected after preparation (P = 0.64 and P = 0.72, respectively). CONCLUSIONS: This new DMEK graft preparation technique, simulating the opening of a yogurt cup, seems to be a safe and an efficient method, providing shorter preparation time and low failure rates independent of surgeon's experience level.

The Influence of Speed During Stripping in Descemet Membrane Endothelial Keratoplasty Tissue Preparation.

PURPOSE: To evaluate whether the speed of stripping a Descemet membrane endothelial keratoplasty graft influences the graft scroll width. METHODS: Human corneas suitable for research were selected for the study. Pairs of corneas were randomly divided into 2 groups: 1 cornea was stripped with a slow speed (group 1) and the contralateral with a fast speed (group 2). Slow speed was defined as the total time greater than 150 seconds or speed <0.057 mm/s. Fast peeling was defined as less than 75 seconds or speed >0.11 mm/s. The grafts acquired were evaluated by microscopy for the graft scroll width and endothelial cell density change pre- and post-preparation. RESULTS: Twenty corneas of 10 donors were included in the analysis. The mean donor age was 68.6 ± 7.58 years. The mean total time of the tissue preparation in group 1 was 282.7 ± 28 seconds and in group 2 was 126 ± 50 seconds (P-value = 0.00000047). The mean speed of stripping in group 1 was 0.045 ± 0.006 mm/s and in group 2 was 0.266 ± 0.093 mm/s (P-value = 0.000027). The graft width in group 1 was 6.4 ± 0.92 mm and in group 2 was 2.87 ± 0.32 mm (P-value = 0.00000014). The mean endothelial cell loss in group 1 was 389 ± 149 cells/mm and in group 2 was 186 ± 63.44 cells/mm (P-value = 0.00134). CONCLUSION: We found a correlation between the speed of stripping, scroll width, and endothelial cell loss. Slow-peeled Descemet membrane endothelial keratoplasty grafts result in a wider scroll width but were associated with a greater reduction in endothelial cell density.

B cell development is critically dependent on NFATc1 activity.

B cell development in bone marrow is a precisely regulated complex process. Through successive stages of differentiation, which are regulated by a multitude of signaling pathways and an array of lineage-specific transcription factors, the common lymphoid progenitors ultimately give rise to mature B cells. Similar to early thymocyte development in the thymus, early B cell development in bone marrow is critically dependent on IL-7 signaling. During this IL-7-dependent stage of differentiation, several transcription factors, such as E2A, EBF1, and Pax5, among others, play indispensable roles in B lineage specification and maintenance. Although recent studies have implicated several other transcription factors in B cell development, the role of NFATc1 in early B cell developmental stages is not known. Here, using multiple gene-manipulated mouse models and applying various experimental methods, we show that NFATc1 activity is vital for early B cell differentiation. Lack of NFATc1 activity in pro-B cells suppresses EBF1 expression, impairs immunoglobulin gene rearrangement, and thereby preBCR formation, resulting in defective B cell development. Overall, deficiency in NFATc1 activity arrested the pro-B cell transition to the pre-B cell stage, leading to severe B cell lymphopenia. Our findings suggest that, along with other transcription factors, NFATc1 is a critical component of the signaling mechanism that facilitates early B cell differentiation.

NFAT-mediated defects in erythropoiesis cause anemia in Il2-/- mice.

The role of NFAT family transcription factors in erythropoiesis is so far unknown, although their involvement has been suggested previously. We have shown recently that Il2-/- mice develop severe anemia due to defects in KLF1 activity during BM erythropoiesis. Although, KLF1 activity is indispensable for erythropoiesis, the molecular details of Klf1 expression have not yet been elucidated. Here we show that an enhanced NFATc1 activity induced by increased integrin-cAMP signaling plays a critical role in the dysregulation of Klf1 expression and thereby cause anemia in Il2-/- mice. Interestingly, enhanced NFATc1 activity augmented apoptosis of immature erythrocytes in Il2-/- mice. On the other hand, ablation of NFATc1 activity enhanced differentiation of Ter119+ cells in BM. Restoring IL-2 signaling in Il2-/- mice reversed the increase in cAMP-NFAT signaling and facilitated normal erythropoiesis. Altogether, our study identified an NFAT-mediated negative signaling axis, manipulation of which could facilitate erythropoiesis and prevent anemia development.

Interleukin-2-regulatory T cell axis critically regulates maintenance of hematopoietic stem cells.

The role of IL-2 in HSC maintenance is unknown. Here we show that Il2-/- mice develop severe anomalies in HSC maintenance leading to defective hematopoiesis. Whereas, lack of IL-2 signaling was detrimental for lympho- and erythropoiesis, myelopoiesis was enhanced in Il2-/- mice. Investigation of the underlying mechanisms of dysregulated hematopoiesis in Il2-/- mice shows that the IL-2-Treg cell axis is indispensable for HSC maintenance and normal hematopoiesis. Lack of Treg activity resulted in increased IFN-γ production by activated T cells and an expansion of the HSCs in the bone marrow (BM). Though, restoring Treg population successfully rescued HSC maintenance in Il2-/- mice, preventing IFN-γ activity could do the same even in the absence of Treg cells. Our study suggests that equilibrium in IL-2 and IFN-γ activity is critical for steady state hematopoiesis, and in clinical conditions of BM failure, IL-2 or anti-IFN-γ treatment might help to restore hematopoiesis.