Liver Transplantation for Dengue-induced Acute Liver Failure

Although liver involvement has been observed in over two-third cases of dengue viral infection, less than 1% cases progress to dengue-related acute liver failure (D-ALF). Various aspects of management of this disease remain debated including the need and timing of liver transplantation (LT). Moreover, the outcomes of LT for D-ALF have been suboptimal. We present four contrasting cases of D-ALF, two managed with LT and the other two conservatively to highlight the management dilemmas concerning LT in D-ALF. Based on our 4 cases, we would consider dengue shock syndrome, multisystem involvement and neurological deficit not completely accounted for by the ALF as potential contraindications for LT. These would need to be revisited on a case-to-case basis till larger studies define objective selection criteria for LT in D-ALF.

Deceased Donor Liver Transplantation in India: First Report of 5-Y Outcomes

BACKGROUND

Paucity of deceased donor livers has resulted in a 10-fold rise in living donor liver transplantations (LDLTs) performed in India over the past decade. Nonetheless, number of deceased donor liver transplantation (DDLT) performed has improved with the establishment of simplified legal framework for certification of brain death and organ donation. In this study, we present our outcomes of DDLT performed at various centers, comparing their outcomes and provide a snapshot of the increasing number of DDLT across the state over the years.

METHODS

All consecutive patients who underwent liver transplants from January 2010 till December 2019 by our transplant team in the state of Tamil Nadu, India, were included in the study. The program was established initially at the primary hospital in the year 2010 and with the evolution of the initial experience, transplant programs were expanded to the others hospital from the year 2015. Preoperative clinical data, intraoperative characteristics, and posttransplant outcomes of DDLT were analyzed from our prospective database.

RESULTS

A total of 362 DDLTs (331 adults, 31 children) were performed at 11 centers. Median (range) model for end-stage liver disease score was 16 (6-39). Forty-eight split, 11 combined liver kidney, and 4 auxiliary DDLTs were performed. One-, 3-, and 5-y survival was 87.2%, 80.4%, and 76.6% in adults and 80.6%, 80.6%, and 80.6% in children, respectively.

CONCLUSIONS

In a country where over 80% of the LTs are performed as LDLT, we provide the first report of a heartening trend of increasing number of DDLT programs being established with excellent 5-y outcomes.

Propensity score matched analysis and risk stratification of donors with G6PD deficiency in living donor liver transplantation

INTRODUCTION

Glucose 6 phosphate dehydrogenase (G6PD) deficiency (G6PDd) can trigger hemolysis following surgical stress. Differentiating G6PDd-related post-operative hemolytic episodes (PHE) and post-hepatectomy liver failure may be challenging especially in living donors where donor safety is paramount. We analysed outcomes of our cohort of G6PDd liver donors.

METHODS

G6PDd individuals with no evidence of hemolysis were considered as living donors if there was no alternative family donor. Outcomes of G6PDd donors undergoing left lateral/left lobe donation (Group LL) and right lobe donation (Group RL) were compared with non-G6PDd donors matched in a 1:3 ratio using propensity score matching.

RESULTS

59 G6PDd donors (5.8% of 1011) underwent living donor hepatectomy (LiDH) during the study period. LL-G6PDd donors (22.37%) had higher post-operative peak bilirubin level compared to matched controls, but no difference in morbidity or need for post-operative blood transfusion.RL-G6PDd donors (37.63%) had higher peak bilirubin level, morbidity (16.2% vs. 3.6%, p = 0.017) and more post-operative blood transfusion (21.6% vs. 6.4%, p = 0.023) as compared to matched non-G6PDd cohort. Four RL-G6PDd donors (10.8%) developed PHE. Low G6PD activity (15% vs. 40%, p = 0.034) and lower future liver remnant (FLR) (34.3% vs. 37.8%, p = 0.05) were identified as risk factors for PHE.

CONCLUSION

We report the largest to-date series of G6PDd individuals undergoing LiDH and confirm the safety of LL donation in G6PDd. Our analysis identifies specific risk factors for PHE and suggests that right lobe LiDH be avoided in individuals with less than 25% G6PD activity when the FLR is less than 36%.

Experience With Establishing a Robotic Donor Hepatectomy Program for Pediatric Liver Transplantation

BACKGROUND

The benefits of minimal invasive donor hepatectomy, especially for left lateral sectionectomy (LLS) have been unequivocally demonstrated. Moreover, donors in pediatric liver transplantation (LT) are usually parents who need to recover quickly to take care of the child. There are inherent limitations to conventional laparoscopic surgery including surgeon's experience with advanced laparoscopic surgery and steep learning curve which limits the wide application of minimal invasive donor hepatectomy. We share our experience of establishing a program of robotic donor hepatectomy (RDH) and achieving proficiency in performing RDH for pediatric LT.

METHODS

Data were prospectively collected of consecutive LLS RDH based on a structured learning algorithm. Donor and recipient outcomes were analyzed.

RESULTS

Seventy-five consecutive cases of LLS RDH were performed. The median primary warm ischemia time was 6 min (interquartile range [IQR]: 5-7 min). No major complications (grade ≥IIIb Clavien-Dindo) were noted in the cohort. There were no emergency conversion to open surgery and neither were there postoperative explorations through a laparotomy. Seven grafts were hyper-reduced and 5 required venoplasty. Two recipients died because of severe sepsis and multiorgan failure. Major complications occurred in 15 children (20%), none of which were attributable to RDH. Median hospital stay of the donors and recipients was 5 d (IQR: 5-6) and 12 d (IQR: 10-18) respectively.

CONCLUSIONS

We share our experience of starting a RDH program for pediatric LT. We highlight the challenges and our learning algorithm to spur teams on the cusp of starting robotic transplant programs.

Anesthesia and Critical Care for the Prediction and Prevention for Small-for-size Syndrome: Guidelines from the ILTS-iLDLT-LTSI Consensus Conference

BACKGROUND

During the perioperative period of living donor liver transplantation, anesthesiologists and intensivists may encounter patients in receipt of small grafts that puts them at risk of developing small for size syndrome (SFSS).

METHODS

A scientific committee (106 members from 21 countries) performed an extensive literature review on aspects of SFSS with proposed recommendations. Recommendations underwent a blinded review by an independent expert panel and discussion/voting on the recommendations occurred at a consensus conference organized by the International Liver Transplantation Society, International Living Donor Liver Transplantation Group, and Liver Transplantation Society of India.

RESULTS

It was determined that centers with experience in living donor liver transplantation should utilize potential small for size grafts. Higher risk recipients with sarcopenia, cardiopulmonary, and renal dysfunction should receive small for size grafts with caution. In the intraoperative phase, a restrictive fluid strategy should be considered along with routine use of cardiac output monitoring, as well as use of pharmacologic portal flow modulation when appropriate. Postoperatively, these patients can be considered for enhanced recovery and should receive proactive monitoring for SFSS, nutrition optimization, infection prevention, and consideration for early renal replacement therapy for avoidance of graft congestion.

CONCLUSIONS

Our recommendations provide a framework for the optimal anesthetic and critical care management in the perioperative period for patients with grafts that put them at risk of developing SFSS. There is a significant limitation in the level of evidence for most recommendations. This statement aims to provide guidance for future research in the perioperative management of SFSS.

Living Donor Liver transplantation in an alloimmunised patient: Immunological challenges and Management in Indian Settings

Liver transplantation (LT) is often associated with hematological abnormalities with immune or non-immune etiologies and require timely diagnosis and interventions. We report a case of a patient suffering from non-alcoholic steato-hepatitis (NASH) related end stage liver disease (ESLD) with multiple red cell antibodies who underwent LT surgery. In postoperative phase, she developed immune hemolysis as well as acute antibody mediated rejection (AMR) which was managed with therapeutic plasma exchange and IVIG. The case highlights the need to develop an algorithm for red cell and HLA antibody screening in high-risk patients for timely detection and management.

Outcome of Patients Waitlisted for Deceased Donor Liver Transplantation During COVID-19 Pandemic: A Single-Center Experience

Background and aim

COVID-19 pandemic has strained several healthcare resources across the world. While liver transplantation (LT) is the only curative therapy for patients with end-stage liver disease, we aimed to determine the clinical outcome of patients waitlisted for deceased donor liver transplantation (DDLT) during COVID-19 pandemic.

Methods

A retrospective comparative observational study of adult patients waitlisted for DDLT from January 2019 to January 2022 at our liver unit (Dr Rela Institute and Medical Center, Chennai, Tamil Nadu, India) was carried out. Patient demographics, disease etiology, Model for End-Stage Liver Disease - Sodium (MELD-Na) score were calculated for all patients listed during the study period. Clinical event was defined as number of DDLT, death in the absence of transplant, and patients awaiting LT were compared. Statistical analysis was performed with SPSS V24.0.

Results

In total, 310 patients were waitlisted for DDLT, of whom 148, 63, and 99 patients listed during 2019, 2020, and 2021 (till January 2022), respectively; 22 (53.6%), 10 (24.3%), and 9 (21.9%) patients underwent DDLT in the year 2019, 2020, and 2021 (P = 0.000); 137 patients (44.19%) died on the DDLT waitlist of whom 41 (29.9%), 67 (48.9%), and 29 (21.1%) in the year 2019, 2020, and 2021 (P = 0.000), respectively. Waitlist mortality was significantly higher during the COVID first wave.

Conclusion

COVID-19 pandemic has significantly impacted patients waitlisted for DDLT in India. With limited access to healthcare facilities and decreased organ donation rates during the pandemic, there was a considerable reduction in the patients waitlisted for DDLT, lesser number of patients underwent DDLT, and higher waitlist mortality during the pandemic year. Efforts to improve organ donation in India should be strongly implemented.

LTSI Consensus Guidelines: Preoperative Pulmonary Evaluation in Adult Liver Transplant Recipients

The relationship between chronic liver disease and respiratory symptoms and hypoxia is well recognized. Over the last century, three pulmonary complications specific to chronic liver disease (CLD) have been characterized: hepatopulmonary syndrome, portopulmonary hypertension, and hepatic hydrothorax. Apart from that coexisting pulmonary disease like chronic obstructive lung disease and interstitial lung disease also complicate the outcomes after liver transplantation (LT). Assessment for evaluation of underlying pulmonary disorders is essential to improve outcomes in patients with CLD, posted for LT. This consensus guideline of the Liver Transplant Society of India (LTSI) provides a comprehensive review of pulmonary issues in CLD, related and unrelated to underlying liver disease and gives recommendations for pulmonary screening in specific clinical scenarios in adults with chronic liver disease planned for LT. This document also aims to standardize the strategies for preoperative evaluation of these pulmonary issues in this subset of patients. Proposed recommendations were based on selected single case reports, small series, registries, databases, and expert opinion. The paucity of randomized, controlled trials in either of these disorders was noted. Additionally, this review will highlight the lacunae in our current evaluation strategy, challenges faced, and will provide direction to potentially useful futuristic preoperative evaluation strategies.

Anatomical Variations of Left Hepatic Vein and Outflow Reconstruction Techniques in Paediatric Living Donor Liver Transplantation

Anatomical variations of left hepatic vein (LHV) are observed in nearly a third of left lateral segment (LLS) donors in living donor liver transplantation (LDLT). There is paucity of studies and no structured algorithm for customised outflow reconstruction in LLS grafts with variant anatomy. Analysis of a prospectively collected database of 296 LLS paediatric LDLT was done to identify different venous drainage patterns of segments 2 (V2) and 3 (V3). LHV anatomy was classified into three types: type 1(n=270, 91.2%): V2 and V3 joined to form a common trunk which drains into middle hepatic vein (MHV)/inferior vena cava (IVC), subtype 1a length of trunk ≥ 9mm and subtype 1b length of trunk < 9mm; type 2(n=6, 2%): V2 and V3 drain independently into IVC; type 3(n=20, 6.8%): V2 and V3 drain into IVC and MHV respectively. Analysis of post-operative outcomes between LLS grafts with single and reconstructed multiple outflows showed no difference in the occurrence of hepatic vein thrombosis/stenosis, major morbidity (p 0.91) and 5 year survival (log rank p 0.562). This classification is a simple yet effective tool for pre-operative donor assessment and we propose a schema for customised reconstruction of LLS grafts, with excellent and consistently reproducible outcomes.

Role of Combined CT Pulmonary Angiography and Indirect CT Venography in Diagnosing Venous Thromboembolism in COVID-19 Patients - Experience From an Indian Quaternary Centre

OBJECTIVES

To study the role of combined CTPA and indirect CT venogram to diagnose venous thromboembolism (VTE) in patients with COVID-19 pneumonia and to compare the clinical characteristics, laboratory parameters, CT findings and clinical outcomes between the VTE positive and negative groups.

METHODS

In this retrospective study, 131 patients with COVID-19 pneumonia who underwent CTPA and venogram between August 2020 and January 2021 were included. Relevant demographical, clinical and laboratory data and CT images were collected. Two thoracic radiologists independently reviewed the CTPA and venogram images.

RESULTS

VTE was identified in 29 patients (22% of the study population). CT venogram identified DVT in 9 patients. No statistical difference was observed between the two groups with respect to age, gender, BMI and presence of comorbidities. There was a significant difference in the hospital stay duration, which is increased in the VTE positive group. The number of patients who were dependent on oxygen and mortality were also high in the positive group. There was statistically significant difference in the mean D-dimer value and the mean Neutrophil/lymphocyte ratio, which were higher in the VTE positive group.

CONCLUSION

Combined CTPA and venogram can be used as a one-stop investigation for diagnosing PE and DVT of lower limbs in patients with COVID-19 pneumonia. CTPA with venogram should be performed in patients with D-dimer value in the range of 1000 - 1200 μg/L and above to rule out VTE as the hospital stay duration and final outcomes vary between the positive and negative groups.

Enhanced recovery for liver transplantation: recommendations from the 2022 International Liver Transplantation Society consensus conference

There is much controversy regarding enhanced recovery for recipients of liver transplants from deceased and living donors. The objectives of this Review were to summarise current knowledge on individual enhanced recovery elements on short-term outcomes, identify key components for comprehensive pathways, and create internationally accepted guidelines on enhanced recovery for liver-transplant recipients. The ERAS4OLT.org collaborative partnered by the International Liver Transplantation Society performed systematic literature reviews on the effect of 32 relevant enhanced perioperative recovery elements on short-term outcomes, and global specialists prepared expert statements on deceased and living donor liver transplantation. The Grading Recommendations, Assessment, Development and Evaluations approach was used for rating of quality of evidence and grading of recommendations. A virtual international consensus conference was held in January, 2022, in which results were presented, voted on by the audience, and discussed by an independent international jury of eight members, applying the Danish model of consensus. 273 liver transplantation specialists from 30 countries prepared expert statements on elements of enhanced recovery for liver transplantation based on the systematic literature reviews. The consensus conference yielded 80 final recommendations, covering aspects of enhanced recovery for preoperative assessment and optimisation, intraoperative surgical and anaesthetic conduct, and postoperative management for the recipients of liver transplants from both deceased and living donors, and for the living donor. The recommendations represent a comprehensive overview of the relevant elements and areas of enhanced recovery for liver transplantation. These internationally established guidelines could direct the development of enhanced recovery programmes worldwide, allowing adjustments according to local resources and practices.

Consanguineous marriage as a key indicator of isolated congenital dental anomaly among South Indian population - A cross-sectional study

Background

Orofacial anomalies occur due to incomplete fusion of developmental lines in the head and neck region. Dental anomalies regarded as the most common orofacial anomalies either in isolated or syndromic forms arise due to genetic and environmental factors. Among genetic influences, consanguineous marriages are considered as a significant predisposition factor in the transmission of congenital defects and several autosomal recessive diseases from one generation to other with an increased risk of detrimental effects on offspring.

Aim

The present study was aimed to evaluate the prevalence and significant association between consanguinity and isolated dental anomalies with that of nonconsanguineous parents among south-Indian population.

Methodology

A total of 116 participants with and without dental anomalies in isolated form pertaining to tooth size, shape, altered morphology, number and eruption were selected followed by brief case history. Participants with a positive history of consanguinity were categorized as Group A while others were categorized under Group B.

Results

Sixty-four out of 116 participants (55.17%) showed positive consanguinity (Group A) among which 18 females (56%) and 14 males (44%) presented with isolated dental anomalies. 12 females (66.6%) and 9 males (64.2%) in Group A showed significance with first cousin (P = 0.00204) whereas no significance was observed in other consanguinity type (P = 0.7287). Nonetheless, the overall frequency of isolated dental anomalies was slightly higher in Group A than Group B that was statistically significant (P = 0.0213).

Conclusion

A positive correlation between dental anomalies among offspring of consanguineous marriages revealed such prevalence may be attributed to increased risk of recessive deleterious gene expression or defective allele carried to offspring.

Optimizing pre-donation physiologic evaluation for enhanced recovery after living liver donation - Systematic review and multidisciplinary expert panel recommendations

BACKGROUND

While preoperative physiologic evaluation of live liver donors is routinely performed to ensure donor safety and minimize complications, the optimal approach to this evaluation is unknown.

OBJECTIVES

We aim to identify predonation physiologic evaluation strategies to improve postoperative short-term outcomes, enhance donor's recovery, and reduce length of stay. We also aim to provide multidisciplinary expert panel recommendations.

DATA SOURCES

Ovid MEDLINE, Embase, Scopus, Google Scholar, and Cochrane Central.

METHODS

The systematic review followed PRISMA guidelines, and the recommendations were formulated using GRADE approach and experts' opinion. The search included retrospective or prospective studies, describing outcomes of physiologic evaluation predonation. The outcomes of interest were length of stay, postoperative complications (POC), recovery after donation, and mortality. PROSERO protocol ID CRD42021260662.

RESULTS

Of 1386 articles screened, only three retrospective cohort studies met eligibility criteria. Two studies demonstrated no impact of age (< 70 years) on POC. Increased body mass index's (BMI) association with POC was present in one study (23.8 vs 21.7 kg/m2 , OR 1.67 (1.14-2.48), P = .01) and absent in another (< 30 vs 30-35 kg/m2 , P = .61). One study demonstrated decreased risk for postdonation subclinical hepatic dysfunction in donors with higher normal platelet count (PLT). None of the studies noted donor death. Given the scarce data on predonation physiologic testing, the expert panel recommended a battery of tests to guide clinical practice and future investigations.

CONCLUSION

Advancing age (60-69 years) is not a contraindication for liver donation. There is insufficient evidence for a specific predonation BMI cut-off. Abbreviated predonation physiologic testing is recommended in all candidates. Comprehensive testing is recommended in high-risk candidates while considering the pretest probability in various populations (Quality of evidence; Low to Very Low | Grade of Recommendation; Strong).

Propensity Score-Matched Analysis of Posttransplant Outcomes in Living Donor Liver Transplantation for Older Adult Recipients

The impact of increasing recipient age on morbidity and mortality following living donor liver transplantation (LDLT) remains controversial. The study aims to analyze the impact of recipient age on outcomes following LDLT. Data on adult LDLTs performed between November 2009 and February 2020 were retrieved from a prospectively maintained database. Patients were stratified into 2 groups based on recipient age: 18 to 65 years (younger adults) and >65 years (older adults). Propensity score matching (PSM) using nearest-neighbor matching was used to match each older recipient with up to 2 younger adult recipients using multiple preoperative parameters. Outcomes evaluated were duration of ventilation, need for reintubation, tracheostomy, intensive care unit (ICU) readmission, length of ICU and hospital stays, postoperative complications, reoperation within 90 days, and patient survival. A total of 801 adult LDLT recipients were included in the study; 751 (93.7%) were younger adults, and 50 (6.3%) were older adults. Older recipients were more likely to be diabetic (60.0% versus 39.7%) and hypertensive (44.0% versus 20.4%) with preexisting cardiac disease (28.0% versus 11.2%). However, their pretransplant Model for End-Stage Liver Disease score was significantly lower (14.5 versus 17.7), and they were more likely to receive a transplant because of hepatocellular carcinoma (38.0% versus 17.7%). Older recipients had longer durations of ventilation after LT both before (3.7 versus 1.9 days) and after PSM (4.0 versus 1.5 days). After PSM, the 30-day (13.0% versus 2.4%), 90-day (15.2% and 2.4%), and overall mortality rates (21.7% versus 7.1%) were significantly higher for older recipients when compared with younger recipients. There was no difference between the younger and older recipients with respect to other postoperative outcomes. This propensity score-matched study shows that the older LDLT recipients have higher 30-day, 90-day, 1-year, and 5-year mortality rates when compared with matched younger counterparts.

Therapeutic Plasma Exchange for Management of Early Allograft Dysfunction After Living Donor Liver Transplant: An Unmatched Cohort Study

OBJECTIVES

Therapeutic plasma exchange has been reported to be useful in the management of acute liver failure and acute-on-chronic liver failure. This retrospective study evaluated therapeutic plasma exchange as an adjunct to standard supportive care for early allograft dysfunction after living donor liver transplant.

MATERIALS AND METHODS

All consecutive adult living donor liver transplants performed from January 2015 to February 2019 were included. Patients treated without or with therapeutic plasma exchange for early allograft dysfunction (Olthoff criteria) were compared.

RESULTS

There were 465 adult transplant recipients, and 67 (14.4%) had early allograft dysfunction, of which 43 (64%) had therapeutic plasma exchange and 24 (36%) did not. Fourteen patients were excluded, as they had both preoperative and immediate postoperative therapeutic plasma exchange (5 patients with acute liver failure and 9 with acute-on-chronic liver failure). The therapeutic plasma exchange group (n = 29) had more preoperative acute kidney injury (55.2% vs 25.0%; P = .009), lower graft-recipient weight ratio (0.96 vs 1.09; P = .043), and slightly higher final portal pressure (11 vs 10 mg/dL; P = .027). Therapeutic plasma exchange was started at a median of postoperative day 9, with median serum bilirubin of 13.6 mg/dL and a median of 3 sessions per patient. There was no 90-day mortality in the group without therapeutic plasma exchange; however, in the therapeutic plasma exchange group, 13 patients (45%) died (P < .001). Patients who received therapeutic plasma exchange had more septic complications (62.1% vs 12.5%; P < .001) and needed more postoperative renal replacement therapy (51.7% vs 8.3%; P < .001).

CONCLUSIONS

This is the first study to compare patients treated with or without therapeutic plasma exchange for early allograft dysfunction in the living donor liver transplant setting. Within the limitations of this retrospective study, we were unable to confirm whether therapeutic plasma exchange could increase early mortality.

Auto-immune hepatitis following COVID vaccination

Unprecedented loss of life due to the COVID pandemic has necessitated the development of several vaccines in record time. Most of these vaccines have received approval without being extensively whetted for their adverse effect and efficacy profiles. Most adverse effects have been mild, nonetheless, more serious thromboembolic events have also been reported. Autoimmune hepatitis (AIH) can occur in predisposed individuals where an immune mediated reaction against hepatocytes is triggered by environmental factors. Vaccines are a very rare cause of AIH. We report two such cases of AIH triggered by COVID (Covishield) vaccination. While one patient made an uneventful recovery, another succumbed to the liver disease. Ours is the first report of Covishield vaccination related AIH and second ever after any form of COVID vaccination. We hope that our report does not deter COVID vaccination drives. However, we also hope to raise awareness of its potential side effects and the increased role of pharmacovigilance in guiding treatment.

Liver Transplantation Society of India Guidelines for the Management of Acute Liver Injury Secondary to Yellow Phosphorus-Containing Rodenticide Poisoning Using the Modified Delphi Technique of Consensus Development

BACKGROUND

Acute liver failure caused by the ingestion of yellow phosphorus-containing rodenticide has been increasing in incidence over the last decade and is a common indication for emergency liver transplantation in Southern and Western India and other countries. Clear guidelines for its management are necessary, given its unpredictable course, potential for rapid deterioration and variation in clinical practice.

METHODS

A modified Delphi approach was used for developing consensus guidelines under the aegis of the Liver Transplantation Society of India. A detailed review of the published literature was performed. Recommendations for three areas of clinical practice, assessment and initial management, intensive care unit (ICU) management and liver transplantation, were developed.

RESULTS

The expert panel consisted of 16 clinicians, 3 nonclinical specialists and 5 senior advisory members from 11 centres. Thirty-one recommendations with regard to criteria for hospital admission and discharge, role of medical therapies, ICU management, evidence for extracorporeal therapies such as renal replacement therapy and therapeutic plasma exchange, early predictors of need for liver transplantation and perioperative care were developed based on published evidence and combined clinical experience.

CONCLUSION

Development of these guidelines should help standardise care for patients with yellow phosphorus poisoning and identify areas for collaborative research.

Thrombotic Thrombocytopenic Purpura After Live Liver Donation: Villain or Scapegoat?

Living donor liver transplantation is a complex surgery, where the donor’s safety is of paramount importance. Despite all precautions, donor morbidity may be inevitable, and long-term follow-up data attest to this fact. However, being a “past donor” all ailments are intuitively attributed to the donation process, which may not always be the case. We present the case of a 47-year-old lady, who developed thrombotic thrombocytopenic purpura secondary to systemic lupus erythematosus 18 months following her liver donation, when she detected to be anti-nuclear antibody (ANA) positive. She developed neurological signs and was managed successfully with therapeutic plasma exchange and steroids. She was discharged home on immunosuppression and remains well on follow-up. We present the medical and social issues that were addressed in the case and highlight the need for a more stringent follow-up protocol in those who are ANA positive. This would also help detect morbidities that may be unrelated to the donation process.

Renal Dysfunction in Cirrhosis: Critical Care Management

Cirrhotic patients with manifestations of the end-stage liver disease have a high risk for developing renal dysfunction even with minor insults. The development of renal dysfunction increases the morbidity and mortality of these patients. Causes of renal dysfunction in cirrhotics can be due to hepatorenal syndrome (HRS) or acute kidney injury (AKI) resulting from prerenal, renal, and postrenal causes. Development of pretransplant renal dysfunction has been shown to affect post-liver transplantation outcomes. Early detection and aggressive strategies for the prevention of further progression of renal dysfunction seem to decrease the morbidity and improve survival in this group of patients. This article aims to outline the pathogenesis of renal dysfunction in cirrhosis, etiological factors, and evaluation of renal dysfunction, strategies for aggressive therapy for renal dysfunction, the indications of renal replacement therapy (RRT) in this group of patients, and the various modalities of RRT with their merits and demerits. A thorough understanding of the pathogenesis, early detection, and aggressive corrective measures for AKI can prevent further progression. In conclusion, a good knowledge of treatment modalities available for renal dysfunction in cirrhosis and institution of timely interventions can significantly improve survival in this group of patients.

Living Donor Liver Transplantation Following Transcatheter Aortic Valve Implantation for Aortic Valvular Disease

Over the last few decades, outcomes with living donor liver transplantation (LDLT) have improved significantly. This has resulted in patients who were denied liver transplantation previously, due to various comorbidities and high risk, now being considered for LDLT. This includes patients with severe valvular heart disease such as aortic stenosis. These patients require aortic valve replacement to help cope with significant perioperative hemodynamic changes. High-risk cardiac procedures like aortic valve replacement are associated with serious perioperative morbidity and mortality in patients with end-stage liver disease. Since the advent of transcatheter aortic valve implantation (TAVI) in 2002, there have been a few case reports of its successful use prior to deceased donor liver transplantation, but there is no literature on this procedure before LDLT. In this article, we report our experience with 2 patients, the first patient with infective endocarditis-induced acute aortic regurgitation and the second patient with bicuspid aortic stenosis who underwent uneventful TAVI followed by successful LDLT. In conclusion, with the increasing expertise and experience in this procedure, an increasing number of potential recipients, previously considered as high-risk transplant candidates, can now be offered liver transplantation by performing pretransplant TAVI.

Double-blind randomized controlled trial of the routine perioperative use of terlipressin in adult living donor liver transplantation

Perioperative terlipressin (Tp) during living donor liver transplantation (LDLT) has been shown to reduce intraoperative portal pressures and improve renal function. Its role and safety profile have never been evaluated in a double-blind randomized controlled trial (RCT). The aim was to evaluate the hemodynamic effects, clinical benefits, and safety of perioperative Tp infusion in adult LDLT. This was a single-center double-blind RCT. Consenting adults with chronic liver disease and low risk of posttransplant renal dysfunction undergoing their first LDLT were randomized. The study group (terlipressin group [TpG]) received an initial bolus of Tp during surgery followed by a Tp infusion for 72 hours in the postoperative period. The placebo group (PbG) received a saline infusion. The primary endpoint was portal pressure after arterial reperfusion. Multiple intraoperative and postoperative variables served as secondary endpoints. A total of 41 patients were enrolled in the trial (TpG, 21; PbG, 20). There were no significant differences in intraoperative portal pressures, blood loss, fluid requirement, vasopressor requirement, or urine output. Peak intraoperative and end of surgery lactate levels were significantly higher in the Tp group. There was no difference in postoperative liver function tests. Incidence of acute kidney injury as assessed by Risk, Injury, Failure, Loss, and End-Stage Kidney Disease criteria was lower in the Tp group (27% versus 60%; P = 0.04). The TpG had less postoperative ascites, a lower need for percutaneous interventions, and a shorter hospital stay. Incidence of bradycardia requiring pharmacological intervention and withdrawal from study was significantly higher in the TpG. In conclusion, this study has not demonstrated a reduction in postreperfusion portal pressure with Tp. However, Tp infusion reduced postoperative ascitic drain output resulting in less frequent percutaneous interventions and reduced hospital stay. Intraoperative hyperlactatemia and symptomatic bradycardia are major concerns. Its use should be restricted to patients with high-volume ascites, and it needs close monitoring during drug infusion. Liver Transplantation 23 1007-1014 2017 AASLD.

Small-for-Size Syndrome: Bridging the Gap Between Liver Transplantation and Graft Recovery

In living donor liver transplantation, optimal graft size is estimated from values like graft volume/standard liver volume and graft/recipient body weight ratio but the final functional hepatic mass is influenced by other donor and recipient factors. Grafts with insufficient functional hepatic mass can produce a life-threatening condition with rapidly progressive liver failure called small-for-size syndrome (SFSS). Diagnosis of SFSS requires careful surveillance for signs of inadequate hepatocellular function, residual portal hypertension, and systemic inflammation that suggest rapidly progressive liver failure. Early diagnosis, symptom control, and addressing the cause of SFSS may prevent the need for retransplantation. With increased attention to avoiding donor risk, intensivists will be confronted with more SFSS recipients. In this review, we aim to outline a systematic approach to the medical management of patients with SFSS by providing a concise synopsis of general supportive care—neurological, cardiovascular, and renal support, mechanical ventilation, nutritional support, infection control, and tailored immunosuppression—with an aim to avoid end-organ damage or death and a review of current interventions including liver support devices, portal flow modulating drugs, and other experimental interventions that aim to preserve existing hepatic mass and improve conditions for hepatic regeneration. We examine evidence for SFSS interventions to provide the reader with information that may assist in clinical decision making. Points of controversy in care are purposefully highlighted to identify areas where additional experimental work is still needed. A full understanding of the pathophysiology of SFSS and measures to support liver regeneration will guide effective management.

Molecular cloning, expression analysis and transcript localization of testicular orphan nuclear receptor 2 in the male catfish, Clarias batrachus

Testicular receptor 2 (TR2; also known as Nr2c1) is one of the first orphan nuclear receptors identified and known to regulate various physiological process with or without any ligand. In this study, we report the cloning of full length nr2c1 and its expression analysis during gonadal development, seasonal testicular cycle and after human chorionic gonadotropin (hCG) induction. In addition, in situ hybridization (ISH) was performed to localize nr2c1 transcripts in adult testis and whole catfish (1day post hatch). Tissue distribution and gonadal ontogeny studies revealed high expression of nr2c1 in developing and adult testis. Early embryonic stage-wise expression of nr2c1 seems to emphasize its importance in cellular differentiation and development. Substantial expression of nr2c1 during pre-spawning phase and localization of nr2c1 transcripts in sperm/spermatids were observed. Significant upregulation after hCG induction indicate that nr2c1 is under the regulation of gonadotropins. Whole mount ISH analysis displayed nr2c1 expression in notochord indicating its role in normal vertebrate development. Taken together, our findings suggest that nr2c1 may have a plausible role in the testicular and embryonic development of catfish.

Anaesthesia and intensive care for simultaneous liver-kidney transplantation: A single-centre experience with 12 recipients

Background and Aims:

The perioperative management of patients presenting for simultaneous liver and kidney transplantation (SLKT) is a complex process. We analysed SLKTs performed in our institution to identify preoperative, intraoperative and post-operative challenges encountered in the management.

Methods:

We retrospectively studied the case records of 12 patients who underwent SLKT between 2009 and 2014 and analysed details of pre-operative evaluation and optimisation, intraoperative anaesthetic management and the implications of use of perioperative continuous renal replacement therapy (CRRT) and the post-operative course of these patients.

Results:

Of the total 12 cases, 4 were under 16 years of age. The indications for SLKT were primary hyperoxaluria (5), congenital hepatic fibrosis with polycystic kidney disease (2), ethanol-related end-stage liver disease (ESLD) with hepatorenal syndrome type 1 (1). Four patients had ESLD with end-stage renal disease due to other causes. Six recipients received live donor grafts and 6 patients received cadaveric grafts. Seven patients received intraoperative CRRT. Mean duration of surgery was 12.5 h. Cardiac output monitors used were trans-oesophageal echocardiogram (2), pulmonary artery catheter (1) and pulse contour cardiac output monitor (3). There was 1 sepsis-related mortality on 7^th post-operative day.

Conclusion:

A thorough pre-operative evaluation and optimisation, knowledge and anticipation of potential problems, and meticulous intraoperative fluid management guided by appropriate monitoring and use of CRRT when needed can help in achieving successful outcomes.

Safe emergency evacuation of a Tertiary Care Hospital during the "once in a century" floods in Chennai, India

The coastal city of Chennai, India, was inundated by unprecedented heavy rains during the last week of November 2015, in what was billed as a "once in a century" floods. Over 350 people lost their lives in the floods. Global Hospital, a 250-bedded tertiary care hospital in Chennai, was heavily flooded leaving more than 100 patients and their relatives stranded inside with access totally cutoff from the rest of the world. This article describes how these patients, many in the Intensive Care Unit on ventilators, were safely managed within the hospital for over 48 h on very limited power supply and resources and then safely evacuated by fishing boats to three other city hospitals. Careful planning, anticipating hazards, identifying critical areas, effective communication and team work contributed to the successful management of this situation.

Anaesthetic considerations for liver transplantation in propionic acidemia

Propionic acidemia (PA) is an autosomal recessive disorder of metabolism due to deficiency of the enzyme propionyl-CoA carboxylase (PCC) that converts propionyl-CoA to methylmalonyl-CoA with the help of the cofactor biotin inside the mitochondria. The resultant accumulation of propionyl-CoA causes severe hyperammonaemia and life-threatening metabolic acidosis. Based on the positive outcomes, liver transplantation is now recommended for individuals with recurrent episodes of hyperammonaemia or acidosis that is not adequately controlled with appropriate medical therapies. We report anaesthetic management of two children with PA for liver transplantation at our institution. It is essential for the anaesthesiologist, caring for these individuals to be familiar with the manifestations of the disease, the triggers for decompensation and management of an acute episode.

Two-dimensional proteomic analysis of gonads of air-breathing catfish, Clarias batrachus after the exposure of endosulfan and malathion

Endocrine disrupting chemicals have raised public concern, since their effects have been found to interfere with the physiological systems of various organisms, especially during critical stage of development and reproduction. Endosulfan and malathion, pesticides widely used for agricultural purposes, have been known to disrupt physiological functions in aquatic organisms. The current work analyzes the effects of endosulfan (2.5 parts per billion [ppb]) and malathion (10 ppb) on the reproductive physiology of catfish (Clarias batrachus) by evaluating protein expression profiles after 21 days of exposure. The proteomic profile of testis and ovary after exposure to endosulfan showed downregulation of proteins such as ubiquitin and Esco2, and upregulation in melanocortin-receptor-2 respectively. Malathion exposed ovary showed upregulated prolactin levels. Identification of proteins differentially expressed in gonads due to the exposure to these pesticides may serve as crucial indications to denote their disruptive effects at the level of proteins.

Gene expression analysis in gonads and brain of catfish Clarias batrachus after the exposure of malathion

Pesticides like malathion have the potential to disrupt development and reproduction of aquatic organisms including fishes. To investigate the likely consequences of malathion exposure at low doses in juvenile catfish, Clarias batrachus, we studied the expression pattern of genes encoding certain transcription factors, activin A, sex steroid or orphan nuclear receptors and steroidogenic enzymes which are known to be involved in gonadal development along with histological changes. To compare further, we also analyzed certain brain specific genes related to gonadal axis. Fifty days post hatch catfish fingerlings were exposed continuously to 1 and 10 µg/L of malathion for 21 days. Results from these experiments indicated that transcript levels of various genes were altered by the treatments, which may further affect the gonadal development either directly or indirectly through brain. Histological analysis revealed slow progression of spermatogenesis in testis, while in ovary, the oil droplet oocytes were found to be higher after treatment (10 µg/L). Our findings revealed that the exposure of malathion, even at low doses, hinder or modulate early gonadal development differentially by targeting gene expression pattern of transcription factors, activin A, sex steroid or orphan nuclear receptors and steroidogenic enzymes with an evidence on histological changes. Further, some of the genes showed differential expression at the level of brain in male and female sex after the exposure of malathion.

Efficacy of titanium doped-indium tin oxide (Ti/TiO2–ITO) films in rapid oxygen generation under photocatalysis and their suitability for bio-medical application

Fabrication of novel titanium doped ITO films and understanding the mechanism for effective photocatalytic oxygen generation for artificial lung-assistive devices.

PP085. Angiotensin II type 1 receptor antibodies increase angiotensin II sensitivity in pregnant rats

INTRODUCTION

Pregnant women who subsequently develop preeclampsia are highly sensitive to infused angiotensin (Ang) II; the sensitivity persists postpartum. Activating autoantibodies against the Ang II type 1 (AT1) receptor are present in preeclampsia. In vitro and in vivo data suggest that they could be involved in the disease process.

OBJECTIVES

The aim of the study was to show if AT1-AB generated by immunisation alters Ang II sensitivity in pregnant rats.

METHODS

We generated and purified activating antibodies against the AT1 receptor (AT1-AB) by immunizing rabbits against the AFHYESQ epitope of the second extracellular loop, which is the binding epitope of endogenous activating autoantibodies against AT1 from patients with preeclampsia. We then purified AT1-AB using affinity chromatography with the AFHYESQ peptide.

RESULTS

We were able to detect AT1-AB both by ELISA and a functional bioassay. We then passively transferred AT1-AB into pregnant rats, alone or combined with Ang II. AT1-AB activated protein kinase C-alpha and extracellular-related kinase 1/2. Passive transfer of AT1-AB alone or Ang II (435ng/kg per minute) infused alone did not induce a preeclampsia-like syndrome in pregnant rats. However, the combination (AT1-AB plus Ang II) induced hypertension, proteinuria, intrauterine growth retardation, and arteriolosclerosis in the uteroplacental unit. We next performed gene-array profiling of the uteroplacental unit and found that hypoxia-inducible factor 1alpha was upregulated by Ang II plus AT1-AB, which we then confirmed by Western blotting in villous explants. Furthermore, endothelin 1 was upregulated in endothelial cells by Ang II plus AT1-AB. We show that AT1-AB induces Ang II sensitivity.

CONCLUSION

Our mechanistic study supports the existence of an "autoimmune-activating receptor" that could contribute to Ang II sensitivity and possibly to preeclampsia.

Endosulfan and flutamide, alone and in combination, target ovarian growth in juvenile catfish, Clarias batrachus

Juvenile Catfish(es), Clarias batrachus of 50 days post hatch (dph) were exposed to endosulfan (2.5 parts per billion [ppb]) and flutamide (33 ppb), alone and in combination for 50 days to access their impact on ovarian development. The doses used in this study were nominal considering pervious reports. Sampling was done at 100 dph to perform histology and measurement of various transcripts, estradiol-17β and aromatase activity. In general, treatments enhanced expression of ovary-specific transcription factors, steroidogenic enzymes steroidogenic acute regulatory protein and aromatases while transcripts of tryptophan hydroxylase2 (tph2) and catfish gonadotropin-releasing hormone declined in the brain of all treated groups with maximum reduction in the endosulfan group. Significant reduction of tph2 immunoreactivity in the forebrain/telencephalon-preoptic area endorsed our results. Increased number of pre-vitellogenic and less immature oocytes in the treated groups indicated hastened ovarian growth. Elevated ovarian aromatase activity and plasma estradiol-17β levels were noticed in the treated groups with maximum being in the endosulfan group. These data together demonstrate that the exposure of endosulfan causes synchronous precocious ovarian development better than flutamide, alone or in combination. Our results suggest that both endosulfan and flutamide alter ovarian growth by triggering precocious development in catfish.

Endosulfan and flutamide impair testicular development in the juvenile Asian catfish, Clarias batrachus

Endosulfan and flutamide, a widely used pesticide and a prostate cancer/infertility drug, respectively, have an increased risk of causing endocrine disruption if they reach water bodies. Though many studies are available on neurotoxicity/bioaccumulation of endosulfan and receptor antagonism of flutamide, only little is known about their impact on testicular steroidogenesis at molecular level. Sex steroids play an important role in sex differentiation of lower vertebrates including fishes. Hence, a small change in their levels caused by endocrine disruptors affects the gonadal development of aquatic vertebrates significantly. The aim of this study was to evaluate the effects of endosulfan and flutamide on testis-related transcription factor and steroidogenic enzyme genes with a comparison on the levels of androgens during critical period of catfish testicular development. We also analyzed the correlation between the above-mentioned genes and catfish gonadotropin-releasing hormone (cfGnRH)-tryptophan hydroxylase2 (tph2). The Asian catfish, Clarias batrachus males at 50 days post hatch (dph) were exposed to very low dose of endosulfan (2.5 μg/L) and flutamide (33 μg/L), alone and in combination for 50 days. The doses used in this study were far less than those used in the previous studies of flutamide and reported levels of endosulfan in surface water and sediments. Sampling was done at end of the treatments (100 dph) to perform testicular germ cell count (histology), measurements of testosterone (T) and 11-ketotestosterone (11-KT) by enzyme immunoassay and transcript quantification by quantitative real-time PCR. In general, treatments decreased the expression of several genes including testis-related transcription factors (dmrt1, sox9a and wt1), steroidogenic enzymes (11β-hsd2, 17β-hsd12 and P450c17), steroidogenic acute regulatory protein and orphan nuclear receptors (nr2c1 and Ad4BP/SF-1). In contrast, the transcripts of cfGnRH and tph2 were elevated in the brain of all treated groups with maximum elevation in the endosulfan group. However, combination of endosulfan and flutamide (E+F) treatment showed minor antagonism in a few results of transcript quantification. Levels of T and 11-KT were elevated after flutamide and E+F treatments while no change was seen in the endosulfan group signifying the effect of flutamide as an androgen receptor antagonist. All the treatments modulated testis growth by decreasing the progression of differentiation of spermatogonia to spermatocytes. Based on these results, we suggest that the exposure to endosulfan and flutamide, even at low doses, impairs testicular development either directly or indirectly at the level of brain.

Hydrogen sulfide producing enzymes in pregnancy and preeclampsia

Preeclampsia, a human pregnancy specific disorder is characterized by an anti-angiogenic state. As hydrogen sulfide (H(2)S) has pro-angiogenic and anti-oxidative characteristics, we hypothesized that H(2)S levels could play a role in the pathogenesis of preeclampsia and studied the placental expression of the H(2)S-producing enzymes cystathionine-γ-lyase (CSE) and cystathionine-β-synthase (CBS). CBS and CSE protein are expressed in the fetal-placental endothelium and CBS only in Hofbauer cells. CBS mRNA expression is decreased (p = 0.002) in early-onset preeclampsia, while CSE mRNA is unchanged. Thus, down regulation of CBS during early-onset preeclampsia may result in less H(2)S-production and may aid in the anti-angiogenic state.

Expression and immunolocalization of 20β-hydroxysteroid dehydrogenase during testicular cycle and after hCG induction, in vivo in the catfish, Clarias gariepinus

The maturation inducing hormone, 17α,20β-dihydroxy-4-pregnen-3-one (17α,20β-DP) is required for the meiotic maturation and is produced from the precursor 17α-hydroxyprogesterone by the enzyme 20β-hydroxysteroid dehydrogenase (20β-HSD) in several teleosts. Central role of 20β-HSD in ovarian cycle and final oocyte maturation is well studied when compared to spermatogenesis. In the present study, we investigated the localization and expression of 20β-HSD in testicular cycle and gonadotropin induced sperm maturation. During testicular ontogeny, 20β-HSD expression was detectable at 50 and 100 days post-hatch (dph), while the expression was high at 150 dph. In testicular cycle, highest levels of mRNA and protein of 20β-HSD were observed during spawning phase. Intraperitoneal injection of human chorionic gonadotropin (hCG) to prespawning catfish elevated both 20β-HSD transcripts and protein levels when compared to saline treated controls in a time-dependent manner. Serum 17α,20β-DP levels, measured during different phases of testicular cycle as well as following the treatment of hCG, showed a positive correlation with the expression of 20β-HSD. Immunolocalization revealed the presence of 20β-HSD protein predominantly in interstitial cells and spermatogonia/spermatocytes while 20β-HSD was undetectable in haploid cells (spermatids/sperm). These results together with high expression during spawning phase of testicular cycle and after hCG treatment in the prespawning catfish suggests a pivotal role for 20β-HSD during testicular recrudescence leading to sperm maturation. Further studies using various fish models on testicular 20β-HSD may provide interesting details to understand its importance in teleostean spermatogenesis.

Dimorphic expression of various transcription factor and steroidogenic enzyme genes during gonadal ontogeny in the air-breathing catfish, Clarias gariepinus

In the present study the expression of 13 genes known to be involved in sex differentiation and steroidogenesis in catfish was analyzed during gonadal ontogeny by quantitative real-time RT-PCR. Dmrt1 and sox9a showed exclusive expression in male gonads while ovarian aromatase (cyp19a1) and foxl2 were abundant in differentiating female gonads. Most of the genes related to steroidogenesis were expressed only after gonadal differentiation. However, genes coding for 3β-hydroxysteroid dehydrogenase (3β-hsd), 17α-hydroxylase/C17-20 lyase type 1 (cyp17) and steroidogenic acute regulatory protein (star) were barely detectable during gonadal differentiation. Ovarian aromatase, cyp19a1, which is responsible for estradiol-17β biosynthesis in females, was expressed very early in the undifferentiated gonads of catfish, around 30-40 days post hatch (dph). The steroidogenic enzyme, 11β-hydroxylase (cyp11b1) required for the production of 11-ketotestosterone (11-KT) was expressed only after differentiation of testis. These results suggest that estradiol-17β has a critical role in ovarian differentiation, while the role of 11-KT in testicular differentiation is doubtful. In conclusion, dimorphic expression of dmrt1 and sox9a in gonads during early development is required for testicular differentiation, and sex-specific expression of cyp19a1 and foxl2 in females plays a critical role in ovarian development. Our study reveals that the critical period of gonadal differentiation in catfish starts around 30-40 dph when sex-specific genes showed differential expression.

Maternal gene expression profiling during pregnancy and preeclampsia in human peripheral blood mononuclear cells

Preeclampsia is a major obstetrical complication affecting maternal and fetal health. While it is clear that there is a substantial placental contribution to preeclampsia pathogenesis, the maternal contribution is less well characterized. We therefore performed a genome-wide transcriptome analysis to explore disease-associated changes in maternal gene expression patterns in peripheral blood mononuclear cells (PBMCs).

METHODS

Preeclampsia was defined as gestational hypertension, proteinuria and hyperurecimia. Total RNA was isolated from PBMCs obtained from women with uncomplicated pregnancies (n = 5) and women with preeclamptic pregnancies (n = 5). Gene expression analysis was carried out using Agilent oligonucleotide microarrays. Biological pathway analysis was undertaken using Ingenuity Pathway Analysis software. Quantitative real-time PCR (QRTPCR) was performed to validate the gene expression changes of selected genes in normotensive and preeclamptic patients (n = 12 each).

RESULTS

We identified a total of 368 genes that were differentially expressed in women with preeclampsia compared to normal controls with false discovery rate (FDR) controlled at 10%. In follow up experiments we further analyzed the expression levels of a number of genes that were identified as altered by the microarray data including survivin (BIRC5), caveolin (CAV1), GATA binding protein-1 (GATA1), signal tranducer and activator of transcription 1 (STAT1), E2F transcription factor-1 (E2F1), fibronectin-1 (FN1), interleukin-4 (IL-4), matrix metalloprotease-9 (MMP-9) and WAP four disulfide domain protein (WFDC-1) by QRTPCR. Additionally we performed immuno blot analysis and zymography to verify some of these candidate genes at the protein level. Computational analysis of gene function identified an anti-proliferative and altered immune function cellular phenotype in severe preeclamptic samples.

CONCLUSIONS

We have characterized the genome-wide mRNA expression changes associated with preeclampsia-specific genes in circulating maternal blood cells at the time of delivery. In addition to providing information relating to the biological basis of the preeclampsia phenotype, our data provide a number of potential biomarkers for use in the further characterization of this disease.

Human placental adenosine receptor expression is elevated in preeclampsia and hypoxia increases expression of the A2A receptor

Placental hypoxia as a result of impaired trophoblast invasion is suggested to be involved in the pathophysiology of preeclampsia. Hypoxia is a potent stimulus for the release of adenosine, and the actions of adenosine are mediated through four adenosine receptors, A(1), A(2A), A(2B) and A(3). We investigated the presence, distribution and expression of adenosine receptor subtypes in the human placenta, the expression of the adenosine receptors in placentas from pregnancies complicated by preeclampsia, small for gestational age (SGA) infants and uncomplicated pregnancies, and the effect of hypoxia on placental adenosine receptor expression. Immunofluorescent microscopy localized A(1), A(2A), A(2B) and A(3) adenosine receptors to the syncytiotrophoblast, endothelial cells and myofibroblasts within the human placenta. Adenosine receptor protein and message expression levels were significantly higher in placentas from preeclamptic pregnancies with or without SGA infants, but not different in pregnancies with SGA infants alone. In vitro exposure of placental villous explants to hypoxia (2% oxygen) increased the expression of A(2A) adenosine receptor 50%. These data indicate that all four known adenosine receptors are expressed in the human placenta and adenosine receptor expression is significantly higher in pregnancies complicated by preeclampsia. These data are consistent with the hypothesis that differences in placental adenosine receptors may contribute to alterations in placental function in preeclampsia.

Leptin affects system A amino acid transport activity in the human placenta: evidence for STAT3 dependent mechanisms

BACKGROUND

Amino acids are important nutrients during fetal development, and the activity of placental amino acid transporters is crucial in the regulation of fetal growth. Leptin, an adipocyte- and placenta-derived hormone, has been proposed to act as a peripheral signal in reproduction in humans. Leptin is elevated during pregnancy and elevated further in pathologic pregnancies such as preeclampsia. However, the role of leptin in placental function has not been fully elucidated. We hypothesize that leptin plays a role in the regulation of placental amino acid transport by activation of the JAK-STAT pathway.

METHODS

Placental amino acid transport, specifically system A transport was studied in placental villous fragments using the amino acid analog, methylaminoisobutyric acid (MeAIB). Specific inhibitors of the JAK-STAT signal transduction pathway were used to further elucidate their role in leptin-mediated effects on amino acid transport activity. Western blotting was performed to identify STAT3 phosphorylation as a measure of leptin receptor activation.

RESULTS

Leptin significantly increased system A amino acid transporter activity by 22-42% after 1h of incubation. Leptin activated JAK-STAT signaling pathway as evidenced by STAT3 phosphorylation, and inhibition of STAT3 or JAK2 resulted in 36-45% reduction in system A amino acid transporter activity. Furthermore, blocking endogenously produced leptin also decreased system A transport by 45% comparable to STAT3 inhibition.

CONCLUSIONS

These data demonstrate that leptin stimulates system A by JAK-STAT dependent pathway in placental villous fragments. Our findings support the autocrine/paracrine role of leptin in regulating amino acid transport in the human placenta.

Novel soluble Flt-1 isoforms in plasma and cultured placental explants from normotensive pregnant and preeclamptic women

Pregnant women who develop preeclampsia exhibit higher circulating levels of the soluble VEGF receptor-1 (sFlt-1). Recent findings suggest that soluble Flt-1 may contribute to the pathogenesis of preeclampsia by binding and neutralizing vascular endothelial growth factors (VEGF) and placental growth factor (PlGF). Existing literature identifies sFlt-1 as a 100 kDa glycoprotein, a product of an mRNA splice variant. We hypothesized that sFlt-1 expression may be more complex with multiple variants of sFlt-1 as well as multiple sources during normal pregnancy and preeclampsia. Using a combination of affinity purification of sFlt-1 by heparin-agarose and epitope specific antibodies, we performed Western blot analysis with epitope specific antibodies for sFlt-1. Plasma of preeclamptic women exhibits significantly higher amounts of a novel 145 kDa variant of sFlt-1, along with the 100 kDa isoform. We identified sFlt-1 variants in the conditioned medium from placental explant cultures that are hypoxia responsive with varying sizes, including 185, 145,100 and 60 kDa forms, as well as antigenicity. The 145 kDa was similar in antigenicity to the 100 kDa found in plasma whereas the 185 and 60 kDa sFlt-1 demonstrated different epitopes. Deglycosylation studies also confirm that there are multiple sFlt-1 polypeptides. Co-immunoprecipitation with VEGF suggests that these different sFlt isoforms can bind VEGF and therefore, may be of functional importance. Finally, comparison of sFlt-1 in the conditioned medium obtained from cultured cytotrophoblasts, peripheral blood mononuclear cells (PBMCs) and human uterine microvascular cells (HUtMVECs) exhibit mainly the100 kDa sFlt-1. Collectively these data suggest the presence of multiple isoforms of sFlt-1 in the circulation of women with preeclampsia as well as in uncomplicated pregnancies and the possibility of multiple sources. Placental hypoxia may contribute to sFlt-1 over expression but other regulatory mechanisms cannot be ruled out.

Placental system A amino acid transport is reduced in pregnancies with small for gestational age (SGA) infants but not in preeclampsia with SGA infants

Preeclampsia and intrauterine growth restriction (IUGR) are both associated with abnormal remodeling of maternal spiral arteries perfusing the placental site. This would be expected to be associated with reduced fetal growth, yet only one third of infants of mothers with preeclampsia are growth restricted. Infants with IUGR have decreased concentrations of amino acids in their blood and system A amino acid transporter activity is reduced in their placentas. Since infants of preeclamptic pregnancies have increased circulating amino acids, we tested system A amino acid transport activity of placental villous fragments from pregnancies with small for gestational age (SGA) infants with and without maternal preeclampsia and from uncomplicated and preeclamptic pregnancies with normal sized infants. We confirm the reduced uptake of amino acids in SGA pregnancies without preeclampsia but report that placental amino acid uptake of SGA infants with maternal preeclampsia is not reduced and is identical to uptake by normal and preeclamptic pregnancies with normal weight infants.

Circulating and placental endoglin concentrations in pregnancies complicated by intrauterine growth restriction and preeclampsia

Inadequate trophoblast invasion and spiral artery remodeling leading to poor placental perfusion and hypoxia are believed to underlie preeclampsia (PE) and intrauterine growth restriction (IUGR). Recent studies implicate increased circulating endoglin as a contributor to the pathogenesis of PE. The objective of this study was to determine whether placental and circulating endoglin concentrations are altered in pregnancies complicated by intrauterine growth restricted (IUGR) infants and to address the role of hypoxia on the regulation of placental endoglin. We analyzed 10 placentas each from normal pregnant (NP), PE, and IUGR subjects. Endoglin levels were 2.5-fold higher in preeclamptic placentas compared to NP (15.4+/-2.6 versus 5.7+/-1.0, p<0.01). In contrast, endoglin levels were similar in NP and IUGR placentas (5.7+/-1.0 vs 5.9+/-1.1, p=NS). Placentas from pregnancies with both PE and IUGR exhibited endoglin levels comparable to the PE group and significantly different from normotensive pregnancies with and without IUGR pregnancies (mean 14.9+/-4.0, n=9, p=0.013). Soluble endoglin concentrations in maternal plasma were comparable in NP and IUGR, but higher in women with PE (n=10 per group, p<0.05). Despite a 2-fold increase in hypoxia inducible factor, HIF-1alpha, we did not observe endoglin upregulation in NP, PE, or IUGR placental villous explants exposed to hypoxia (2% oxygen). In contrast to PE, placental or circulating endoglin is not increased in normotensive women delivering small, asymmetrically grown (IUGR) infants at term. The placentas of women with IUGR appear to be fundamentally different from PE women with respect to endoglin, despite the proposed common pathology of deficient trophoblast invasion/spiral artery remodeling and poor placental perfusion.