Successful Treatment of Tenofovir Alafenamide-Induced Lactic Acidosis: A Case Report

Nucleoside or nucleotide analogues (NAs) have the potential to cause lactic acidosis by inhibiting DNA polymerase-γ of human mitochondria and impairing aerobic metabolism. Patients may be asymptomatic, have mild non-specific symptoms, or present in multisystem organ failure. There is a paucity of data to guide management of life-threatening lactic acidosis due to NA therapy. Here we describe a case of a 60-year old critically ill male with decompensated cirrhosis secondary to hepatitis B virus (HBV) infection who developed severe lactic acidosis (13.8 mmol/L) 2 days after initiation of tenofovir alafenamide (TAF). All other possible etiologies for the elevated lactate were ruled out. Lactic acidosis resolved rapidly with TAF discontinuation and supplementation with cofactors supporting mitochondrial oxidative phosphorylation, including coenzyme Q10, levocarnitine, riboflavin, and thiamine. This case highlights the ability of TAF to cause lactic acidosis early after therapy initiation, especially in susceptible hosts, and reviews the potential role for cofactor supplementation for drug-induced mitochondrial injury.

Comparison of Non-Tumoral Portal Vein Thrombosis Management in Cirrhotic Patients: TIPS Versus Anticoagulation Versus No Treatment

BACKGROUND

There is a lack of consensus in optimal management of portal vein thrombosis (PVT) in patients with cirrhosis. The purpose of this study is to compare the safety and thrombosis burden change for cirrhotic patients with non-tumoral PVT managed by transjugular intrahepatic portosystemic shunt (TIPS) only, anticoagulation only, or no treatment.

METHODS

This single-center retrospective study evaluated 52 patients with cirrhosis and non-tumoral PVT managed by TIPS only (14), anticoagulation only (11), or no treatment (27). The demographic, clinical, and imaging data for patients were collected. The portomesenteric thrombosis burden and liver function tests at early follow-up (6-9 months) and late follow-up (9-16 months) were compared to the baseline. Adverse events including bleeding and encephalopathy were recorded.

RESULTS

The overall portomesenteric thrombosis burden improved in eight (72%) TIPS patients, three (27%) anticoagulated patients, and two (10%) untreated patients at early follow-up (p = 0.001) and in seven (78%) TIPS patients, two (29%) anticoagulated patients, and three (17%) untreated patients in late follow-up (p = 0.007). No bleeding complications attributable to anticoagulation were observed.

CONCLUSION

TIPS decreased portomesenteric thrombus burden compared to anticoagulation or no treatment for cirrhotic patients with PVT. Both TIPS and anticoagulation were safe therapies.

Pancreas transplantation from hepatitis C viremic donors to uninfected recipients

Despite utilization of hepatitis C viremic organs for hepatitis C naïve recipients (HCV D+/R-) in other solid organ transplants, HCV viremic pancreata remain an unexplored source of donor organs. This study reports the first series of HCV D+/R- pancreas transplants. HCV D+/R- had shorter waitlist times compared to HCV D-/R-, waiting a mean of 16 days from listing for HCV-positive organs. HCV D+/R- had a lower match allocation sequence than HCV D-/R-, and this correlated with receipt of organs with a lower Pancreas Donor Risk Index (PDRI) score. All HCV D+/R- had excellent graft function with a mean follow-up of 438 days and had undetectable HCV RNA levels by a mean of 23 days after initiation of HCV-directed therapy. The rates of infectious complications, reoperation, readmission, rejection, and length of stay were not impacted by donor HCV status. A national review of potential ideal pancreas donors found that 37% of ideal HCV-negative pancreas allografts were transplanted, compared to only 5% of ideal HCV-positive pancreas allografts. The results of the current study demonstrate the safety of accepting HCV-positive pancreata for HCV-naïve recipients and advocates for increased utilization of ideal HCV-positive pancreas allografts.

Hepatic Artery Microvascular Anastomosis in Liver Transplantation: A Systematic Review of the Literature

BACKGROUND

The operating microscope is used in many centers for microvascular hepatic arterial reconstruction in living as well as deceased donor liver transplantation in adult and pediatric recipients. To date, a systematic review of the literature examining this topic is lacking.

METHODS

This systematic review of the literature was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Three different electronic databases (PubMed, Embase OVID, and Cochrane CENTRAL) were queried.

RESULTS

A total of 34 studies were included. The rate of hepatic artery thrombosis (HAT) in noncomparative studies (28) ranged from 0% to 10%, with 8 studies reporting patient deaths resulting from HAT. Within comparative studies, the rate of HAT in patients who underwent arterial reconstruction using the operating microscope ranged from 0% to 5.3%, whereas the rate of HAT in patients who underwent arterial reconstruction using loupe magnification ranged from 0% up to 28.6%, and 2 studies reported patient deaths resulting from HAT. Two comparative studies did not find statistically significant differences between the 2 groups.

CONCLUSIONS

Our comprehensive systematic review of the literature seems to suggest that overall, rates of HAT may be lower when the operating microscope is used for hepatic arterial reconstruction in liver transplantation. However, matched comparisons are lacking and surgical teams need to be mindful of the learning curve associated with the use of the operating microscope as compared with loupe magnification, as well as the logistical and time constraints associated with setup of the operating microscope.

Safety of Combined Yttrium-90 Radioembolization and Immune Checkpoint Inhibitor Immunotherapy for Hepatocellular Carcinoma

PURPOSE

To investigate the safety of yttrium-90 radioembolization in combination with checkpoint inhibitor immunotherapy for the treatment of hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

This single-center retrospective study included 26 consecutive patients with HCC who received checkpoint inhibitor immunotherapy within 90 days of radioembolization from April 2015 to May 2018. Patients had preserved liver function (Child-Pugh scores A-B7) and either advanced HCC due to macrovascular invasion or limited extrahepatic disease (21 patients) or aggressive intermediate stage HCC that resulted in earlier incorporation of systemic immunotherapy (5 patients). Clinical documentation, laboratory results, and imaging results at 1- and 3-month follow-up intervals were reviewed to assess treatment-related adverse events and treatment responses.

RESULTS

The median follow-up period after radioembolization was 7.8 months (95% confidence interval [CI], 5.6-11.8). There were no early (30-day) mortality or grades 3/4 hepatobiliary or immunotherapy-related toxicities. Delayed grades 3/4 hepatobiliary toxicities (1-3 months) occurred in 2 patients in the setting of HCC disease progression. One patient developed pneumonitis. The median overall survival from first immunotherapy was 17.2 months (95% CI, 10.9-23.4). The median overall survival from first radioembolization was 16.5 months (95% CI, 6.6-26.4). From first radioembolization, time to tumor progression was 5.7 months (95% CI, 4.2-7.2), and progression-free survival was 5.7 months (95% CI, 4.3-7.1).

CONCLUSIONS

Radioembolization combined with checkpoint inhibitor immunotherapy in cases of HCC appears to be safe and causes limited treatment-related toxicity. Future prospective studies are needed to identify the optimal combination treatment protocols and evaluate the efficacy of combination therapy.

Repeat A2 Into B Kidney Transplantation After Failed Prior A2 Into B Transplant: A Case Report

Kidneys from donors with blood type A2 can be successfully transplanted into blood type B and O recipients without the need for desensitization if the recipient's starting anti-A hemagglutinin titer is within an acceptable range. National kidney allocation policy now offers priority for eligible B recipients to receive A2 or A2B deceased donor kidneys, and therefore, the frequency with which A2 or A2B to B transplants will occur is expected to increase. The precise mechanisms by which antibody-mediated rejection is averted in these cases despite the presence of both circulating anti-A antibody and expression of the A2 antigen on the graft endothelium are not known. Whether this process mirrors proposed mechanisms of accommodation, which can occur in recipients of ABO incompatible transplants, is also not known. Repeated exposure to mismatched antigens after retransplantation could elicit memory responses resulting in antibody rebound and accelerated antibody-mediated rejection. Whether this would occur in the setting of repeated A2 donor exposure was uncertain. Here we report the case of a patient with history of a prior A2 to B transplant which failed owing to nonimmunologic reasons; the patient successfully underwent a repeat A2 to B transplant. Neither rebound in anti-A2 antibody nor clinical evidence of antibody-mediated rejection were observed after the transplant. Current kidney allocation will likely enable more such transplants in the future, and this may provide a unique patient population in whom the molecular mechanisms of incompatible graft accommodation may be investigated.

Surgical approach, cost, and complications of appendectomy in kidney transplant recipients

Kidney transplant recipients (KTRs) have greater morbidity and length of stay (LOS) following certain surgical procedures than non-KTR. Given that appendectomy is one of the most common surgical procedures, we investigated differences in outcomes between 1336 KTR and 2 640 247 non-KTR postappendectomy at transplant and nontransplant centers in the United States from 2000 to 2011, using NIS data and adjusting for patient-level and hospital-level factors. Postoperative complications were identified using ICD-9 codes. Among KTR, there were no post-appendectomy in-hospital deaths, compared to a 0.2% in non-KTR (P = .5). Overall complications were similar among KTR and non-KTR (17.0% vs 11.6%; aOR:_0.77 1.12_1.61 ). LOS and costs were greater for KTR compared to non-KTR (LOS ratio _1.19 1.31_1.45 ; cost ratio _1.11 1.17_1.26 ). Only 44.8% of KTR had laparoscopic approach compared to 54.5% of non-KTR, but had similar complication rates (10.6 vs 8.7%, P = .5). When treated at transplant centers, KTR had similar complications (aOR _0.44 0.79_1.43 ), but longer LOS (ratio _1.21 1.37_1.55 ) and greater hospital-associated costs (ratio _1.19 1.29_1.41 ) than non-KTR. Conversely, at nontransplant centers, KTR and non-KTR had similar complications (aOR _0.75 1.23_2.0 ), LOS (ratio _0.84 0.96_1.09 ), and cost (ratio _0.93 1.01_1.10 ). Contrary to other procedures, KTR did not constitute a high-risk group for patients undergoing appendectomy.

Single-Center Experience in Pre-transplant Hepatitis C Virus (HCV) Treatment Among Living Donor Liver Transplant Candidates: Bridging the Direct-Acting Antivirals (DAA)

BACKGROUND Treatment with DAAs before deceased donor liver transplantation has been shown to be an effective strategy to prevent post-transplant HCV recurrence, with a 95% cure-rate among individuals who achieve undetectable HCV VL for ≥30 days pre- transplant. This strategy has not been evaluated in LDLT. MATERIAL AND METHODS We evaluated outcomes in LDLT recipients treated with DAAs pre-transplant and bridged with 4 weeks of post-transplant SOF. All cases of LDLT at Johns Hopkins (1/1/2014-3/1/15) were retrospectively reviewed. RESULTS There were 4 HCV+ LDLT cases treated with DAAs pre- and post-transplant. Pre-transplant DAA regimens included SOF plus SIM in 2 cases of HCC and SOF plus RBV in 2 cases of ESLD. All patients achieved negative VL by week 7 of treatment and all patients had at least 30 days of HCV RNA negativity at the time of LDLT. Patient 4 had a delay in LDLT due to uncontrolled pulmonary hypertension, and experienced viral breakthrough because of treatment interruption. Due to concerns for SOF resistance, a salvage regimen of LDV-SOF and SIM was used. Post-LDLT patients 1-3 received 4 weeks of SOF monotherapy and patient 4 received 14 weeks of LDV-SOF. Three patients achieved SVR12. One died from non-HCV related complications at 4 months post-LDLT. CONCLUSIONS Our preliminary experience suggests that bridging DAAs pre- and post-LDLT is an effective strategy to prevent HCV recurrence. With delays in transplant and prolonged use of SOF/RBV, there is a risk of viral breakthrough, but a salvage strategy of triple DAA therapy can be effective.

Portopulmonary Hypertension and Liver Transplant: Recent Review of the Literature

Portopulmonary hypertension is one of the main pulmonary conditions affecting patients with liver disease and/or portal hypertension. Other conditions include hepatopulmonary syndrome and hepatic hydrothorax. Portopulmonary hypertension is caused by pulmonary vasoconstriction and increased pulmonary vascular resistance. It develops as a result of portal hypertension with or without liver disease and is associated with a higher morbidity and mortality. However, portopulmonary hypertension is usually asymptomatic; the most common symptoms are dyspnea, fatigue, and peripheral edema. All liver transplant candidates should be screened for potential portopulmonary hypertension because its coexistence can affect survival rates after transplant. All patients with cirrhosis who present with dyspnea should also be screened. Transthoracic echocardiography is a noninvasive, useful method for screening, but right heart-sided catheterization remains the criterion standard for diagnosis. Portopulmonary hypertension carries a poor prognosis without liver transplant, and its severe form is considered to be a contraindication for liver transplant. Treating patients with pulmonary arterial hypertension-specific therapies before liver transplant for moderate and severe portopulmonary hypertension appears to be beneficial.

Hepatopulmonary Syndrome and Liver Transplantation: A Recent Review of the Literature

A severe and common pulmonary vascular complication of liver disease is hepatopulmonary syndrome (HPS). It is a triad of liver dysfunction and/or portal hypertension, intrapulmonary vascular dilatations, and increased alveolar-arterial oxygen gradient. Prevalence varies according to various study groups from 4%-47%. While the most common presenting symptom of HPS is dyspnea, it is usually asymptomatic, and thus all liver transplant candidates should be screened for its presence. Pulse oximetry is a useful screening method, but arterial blood gas examination is the gold standard. If there is an abnormal P (A-a)O2 gradient, microbubble transthoracic echocardiography should be done for diagnosis. Outcome is unpredictable, and there is currently no effective medical therapy. The only effective therapy is considered to be liver transplantation. Complete resolution of HPS after liver transplantation is seen within a year in most HPS patients.

Magnetic Resonance Imaging in Diagnosis and Monitoring of Hepatocellular Carcinoma in Liver Transplantation: A Comprehensive Review

Hepatocellular carcinoma (HCC) is the most common primary liver cancer. One of the most important risk factors of HCC is cirrhosis. The optimal treatment of HCC is liver transplantation, since it treats both the underlying cirrhosis and the cancer. Patients that have risk factors should be included in surveillance programs since HCC can be cured only during the early stages. Surveillance can be performed by ultrasonography (US), which is an inexpensive, non-invasive, and widely available technique, but it is considered to have a low sensitivity. If a suspicious lesion is detected on US exam, computerized tomography (CT) or magnetic resonance imaging (MRI) can be used to further evaluate this lesion. MRI is considered to be superior to CT because it has greater contrast resolution and tissue characterization. In this article, we present a review of MRI for HCC in liver transplantation (LT) with a focus on characteristic MR features of this tumor and current guidelines.

Sarcopenia adversely impacts postoperative complications following resection or transplantation in patients with primary liver tumors

BACKGROUND

Sarcopenia is a surrogate marker of patient frailty that estimates the physiologic reserve of an individual patient. We sought to investigate the impact of sarcopenia on short- and long-term outcomes in patients having undergone surgical intervention for primary hepatic malignancies.

METHODS

Ninety-six patients who underwent hepatic resection or liver transplantation for HCC or ICC at the John Hopkins Hospital between 2000 and 2013 met inclusion criteria. Sarcopenia was assessed by the measurement of total psoas major volume (TPV) and total psoas area (TPA). The impact of sarcopenia on perioperative complications and survival was assessed.

RESULTS

Mean age was 61.9 years and most patients were men (61.4 %). Mean adjusted TPV was lower in women (23.3 cm(3)/m) versus men (34.9 cm(3)/m) (P < 0.01); 47 patients (48.9 %) had sarcopenia. The incidence of a postoperative complication was 40.4 % among patients with sarcopenia versus 18.4 % among patients who did not have sarcopenia (P = 0.01). Of note, all Clavien grade ≥3 complications (n = 11, 23.4 %) occurred in the sarcopenic group. On multivariable analysis, the presence of sarcopenia was an independent predictive factor of postoperative complications (OR = 3.06). Sarcopenia was not associated with long-term survival (HR = 1.23; P = 0.51).

CONCLUSIONS

Sarcopenia, as assessed by TPV, was an independent factor predictive of postoperative complications following surgical intervention for primary hepatic malignancies.

Surgical management of early and late ureteral complications after renal transplantation: techniques and outcomes

BACKGROUND

In this study, we present our experience with ureteral complications requiring revision surgery after renal transplantation and compare our results to a matched control population.

METHODS

We performed a retrospective analysis of our database between 1997 and 2012. We divided the cases into early (<60 d) and late repairs. Kaplan-Meier and Cox proportional hazards models were used to compare graft survival between the intervention cohort and controls generated from the Scientific Registry of Transplant Recipients data set.

RESULTS

Of 2671 kidney transplantations, 51 patients were identified as to having undergone 53 ureteral revision procedures; 43.4% of cases were performed within 60 d of the transplant and were all associated with urinary leaks, and 49% demonstrated ureteral stenosis. Reflux allograft pyelonephritis and ureterolithiasis were each the indication for intervention in 3.8%; 15.1% of the lesions were located at the anastomotic site, 37.7% in the distal segment, 7.5% in the middle segment, 5.7% proximal ureter, and 15.1% had a long segmental stenosis. In 18.9%, the location was not specified. Techniques used included ureterocystostomy (30.2%), ureteroureterostomy (34%), ureteropyelostomy (30.1%), pyeloileostomy (1.9%), and ureteroileostomy (3.8%). No difference in overall graft survival (HR 1.24 95% CI 0.33-4.64, p = 0.7) was detected when compared to the matched control group.

CONCLUSION

Using a variety of techniques designed to re-establish effective urinary flow, we have been able to salvage a high percentage of these allografts. When performed by an experienced team, a ureteric complication does not significantly impact graft survival or function as compared to a matched control group.

Actual and perceived knowledge of kidney transplantation and the pursuit of a live donor

BACKGROUND

Live donor kidney transplantation (LDKT) remains underutilized, partly resulting from the challenges many patients face in asking someone to donate. Actual and perceived kidney transplantation (KT) knowledge are potentially modifiable factors that may influence this process. Therefore, we sought to explore the relationships between these constructs and the pursuit of LDKT.

METHODS

We conducted a cross-sectional survey of transplant candidates at our center to assess actual KT knowledge (5-point assessment) and perceived KT knowledge (5-point Likert scale, collapsed empirically to 4 points); we also asked candidates if they had previously asked someone to donate. Associations between participant characteristics and having asked someone to donate were quantified using modified Poisson regression.

RESULTS

Of 307 participants, 45.4% were female, 56.4% were non-white race, and 44.6% had previously asked someone to donate. In an adjusted model that included both actual and perceived knowledge, each unit increase in perceived knowledge was associated with 1.21-fold (95% CI: 1.03-1.43, P=0.02) higher likelihood of having asked someone to donate, whereas there was no statistically significant association with actual knowledge (RR=1.08 per unit increase, 95% CI: 0.99-1.18, P=0.10). A conditional forest analysis confirmed the importance of perceived but not actual knowledge in predicting the outcome.

CONCLUSIONS

Our results suggest that perceived KT knowledge is more important to a patient's pursuit of LDKT than actual knowledge. Educational interventions that seek to increase patient KT knowledge should also focus on increasing confidence about this knowledge.

Colony-stimulating factor 1 receptor signaling is necessary for microglia viability, unmasking a microglia progenitor cell in the adult brain

The colony-stimulating factor 1 receptor (CSF1R) is a key regulator of myeloid lineage cells. Genetic loss of the CSF1R blocks the normal population of resident microglia in the brain that originates from the yolk sac during early development. However, the role of CSF1R signaling in microglial homeostasis in the adult brain is largely unknown. To this end, we tested the effects of selective CSF1R inhibitors on microglia in adult mice. Surprisingly, extensive treatment results in elimination of ∼99% of all microglia brain-wide, showing that microglia in the adult brain are physiologically dependent upon CSF1R signaling. Mice depleted of microglia show no behavioral or cognitive abnormalities, revealing that microglia are not necessary for these tasks. Finally, we discovered that the microglia-depleted brain completely repopulates with new microglia within 1 week of inhibitor cessation. Microglial repopulation throughout the CNS occurs through proliferation of nestin-positive cells that then differentiate into microglia.

Perioperative complications after live-donor hepatectomy

Current studies of complications following donor hepatectomy may not be generalizable to all hospitals performing this procedure. To address this, live liver donors were identified in the Nationwide Inpatient Sample (2000-2008). Complications after donor hepatectomy were categorized using International Classification of Diseases, Ninth Revision codes and risk factors for complications were tested using logistic regression. Negative binomial regression models were used to estimate the increase in length of stay and hospital charge associated with complications. Among 555 donors (representing 2783 donors nationwide), 23% had 1 or more complications and 5% had a major complication. The most common complications were ileus (27%) and atelectasis (26%). No patient or hospital factors were associated with complications. Having any complication was associated with increased length of stay (incidence rate ratio, 1.36; 95% CI, 1.16-1.58; P < .001) and hospital charge (incidence rate ratio, 1.25; 95% CI, 1.09-1.44; P = .002). Approximately 25% of liver donors have complications immediately postoperatively but most are minor, lending support to current practices in live liver donation and donor selection.

Eculizumab prevents recurrent antiphospholipid antibody syndrome and enables successful renal transplantation

Renal transplantation in patients with antiphospholipid antibodies has historically proven challenging due to increased risk for thrombosis and allograft failure. This is especially true for patients with antiphospholipid antibody syndrome (APS) and its rare subtype, the catastrophic antiphospholipid antibody syndrome (CAPS). Since a critical mechanism of thrombosis in APS/CAPS is one mediated by complement activation, we hypothesized that preemptive treatment with the terminal complement inhibitor, eculizumab, would reduce the extent of vascular injury and thrombosis, enabling renal transplantation for patients in whom it would otherwise be contraindicated. Three patients with APS, two with a history of CAPS, were treated with continuous systemic anticoagulation together with eculizumab prior to and following live donor renal transplantation. Two patients were also sensitized to human leukocyte antigens (HLA) and required plasmapheresis for reduction of donor-specific antibodies. After follow-up ranging from 4 months to 4 years, all patients have functioning renal allografts. No systemic thrombotic events or early graft losses were observed. While the appropriate duration of treatment remains to be determined, this case series suggests that complement inhibitors such as eculizumab may prove to be effective in preventing the recurrence of APS after renal transplantation.

The aggressive phenotype revisited: utilization of higher-risk liver allografts

Organ shortage has led to increased utilization of higher risk liver allografts. In kidneys, aggressive center-level use of one type of higher risk graft clustered with aggressive use of other types. In this study, we explored center-level behavior in liver utilization. We aggregated national liver transplant recipient data between 2005 and 2009 to the center-level, assigning each center an aggressiveness score based on relative utilization of higher risk livers. Aggressive centers had significantly more patients reaching high MELDs (RR 2.19, 2.33 and 2.28 for number of patients reaching MELD>20, MELD>25 and MELD>30, p<0.001), a higher organ shortage ratio (RR 1.51, 1.60 and 1.51 for number of patients reaching MELD>20, MELD>25 and MELD>30 divided by number of organs recovered at the OPO, p<0.04), and were clustered within various geographic regions, particularly regions 2, 3 and 9. Median MELD at transplant was similar between aggressive and nonaggressive centers, but average annual transplant volume was significantly higher at aggressive centers (RR 2.27, 95% CI 1.47-3.51, p<0.001). In cluster analysis, there were no obvious phenotypic patterns among centers with intermediate levels of aggressiveness. In conclusion, highwaitlist disease severity, geographic differences in organ availability, and transplant volume are the main factors associated with the aggressive utilization of higher risk livers.

Pregnancy outcomes of liver transplant recipients: a systematic review and meta-analysis

Approximately 14,000 women of reproductive age are currently living in the United States after liver transplantation (LT), and another 500 undergo LT each year. Although LT improves reproductive function in women with advanced liver disease, the associated pregnancy outcomes and maternal-fetal risks have not been quantified in a broad manner. To obtain more generalizable inferences, we performed a systematic review and meta-analysis of articles that were published between 2000 and 2011 and reported pregnancy-related outcomes for LT recipients. Eight of 578 unique studies met the inclusion criteria, and these studies represented 450 pregnancies in 306 LT recipients. The post-LT live birth rate [76.9%, 95% confidence interval (CI) = 72.7%-80.7%] was higher than the live birth rate for the US general population (66.7%) but was similar to the post-kidney transplantation (KT) live birth rate (73.5%). The post-LT miscarriage rate (15.6%, 95% CI = 12.3%-19.2%) was lower than the miscarriage rate for the general population (17.1%) but was similar to the post-KT miscarriage rate (14.0%). The rates of pre-eclampsia (21.9%, 95% CI = 17.7%-26.4%), cesarean section delivery (44.6%, 95% CI = 39.2%-50.1%), and preterm delivery (39.4%, 95% CI = 33.1%-46.0%) were higher than the rates for the US general population (3.8%, 31.9%, and 12.5%, respectively) but lower than the post-KT rates (27.0%, 56.9%, and 45.6%, respectively). Both the mean gestational age and the mean birth weight were significantly greater (P < 0.001) for LT recipients versus KT recipients (36.5 versus 35.6 weeks and 2866 versus 2420 g). Although pregnancy after LT is feasible, the complication rates are relatively high and should be considered during patient counseling and clinical decision making. More case and center reports are necessary so that information on post-LT pregnancy outcomes and complications can be gathered to improve the clinical management of pregnant LT recipients. Continued reporting to active registries is highly encouraged at the center level.

Center-level factors and racial disparities in living donor kidney transplantation

BACKGROUND

On average, African Americans attain living donor kidney transplantation (LDKT) at decreased rates compared with their non-African American counterparts. However, center-level variations in this disparity or the role of center-level factors is unknown.

STUDY DESIGN

Observational cohort study.

SETTING & PARTICIPANTS

247,707 adults registered for first-time kidney transplants from 1995-2007 as reported by the Scientific Registry of Transplant Recipients.

PREDICTORS

Patient-level factors (age, sex, body mass index, insurance status, education, blood type, and panel-reactive antibody level) were adjusted for in all models. The association of center-level characteristics (number of candidates, transplant volume, LDKT volume, median time to transplant, percentage of African American candidates, percentage of prelisted candidates, and percentage of LDKT) and degree of racial disparity in LDKT was quantified.

OUTCOMES

Hierarchical multivariate logistic regression models were used to derive center-specific estimates of LDKT attainment in African American versus non-African American candidates.

RESULTS

Racial parity was not seen at any of the 275 transplant centers in the United States. At centers with the least racial disparity, African Americans had 35% lower odds of receiving LDKT; at centers with the most disparity, African Americans had 76% lower odds. Higher percentages of African American candidates (interaction term, 0.86; P = 0.03) and prelisted candidates (interaction term, 0.80; P = 0.001) at a given center were associated with increased racial disparity at that center. Higher rates of LDKT (interaction term, 1.25; P < 0.001) were associated with less racial disparity.

LIMITATIONS

Some patient-level factors are not captured, including a given patient's pool of potential donors. Geographic disparities in deceased donor availability might affect LDKT rates. Center-level policies and practices are not captured.

CONCLUSIONS

Racial disparity in attainment of LDKT exists at every transplant center in the country. Centers with higher rates of LDKT attainment for all races had less disparity; these high-performing centers might provide insights into policies that might help address this disparity.

Estimates of early death, acute liver failure, and long-term mortality among live liver donors

BACKGROUND & AIMS

We sought to estimate the risk of perioperative mortality or acute liver failure for live liver donors in the United States and avoid selection or ascertainment biases and sample size limitations.

METHODS

We followed up 4111 live liver donors in the United States between April 1994 and March 2011 for a mean of 7.6 years; deaths were determined from the Social Security Death Master File. Survival data were compared with those from live kidney donors and healthy participants of the National Health and Nutrition Examination Survey (NHANES) III.

RESULTS

Seven donors had early deaths (1.7 per 1000; 95% confidence interval [CI], 0.7-3.5); risk of death did not vary with age of the liver recipient (1.7 per 1000 for adults vs 1.6 per 1000 for pediatric recipients; P = .9) or portion of liver donated (2.0 per 1000 for left lateral segment, 2.8 per 1000 for left lobe, and 1.5 per 1000 for right lobe; P = .8). There were 11 catastrophic events (early deaths or acute liver failures; 2.9 per 1000; 95% CI, 1.5-5.1); similarly, risk did not vary with recipient age (3.1 per 1000 adult vs 1.6 per 1000 pediatric; P = .4) or portion of liver donated (2.0 per 1000 for left lateral segment, 2.8 per 1000 for left lobe, and 3.3 per 1000 for right lobe; P = .9). Long-term mortality of live liver donors was comparable to that of live kidney donors and NHANES participants (1.2%, 1.2%, and 1.4% at 11 years, respectively; P = .9).

CONCLUSIONS

The risk of early death among live liver donors in the United States is 1.7 per 1000 donors. Mortality of live liver donors does not differ from that of healthy, matched individuals over a mean of 7.6 years.

Desensitization in HLA-incompatible kidney recipients and survival

BACKGROUND

More than 20,000 candidates for kidney transplantation in the United States are sensitized to HLA and may have a prolonged wait for a transplant, with a reduced transplantation rate and an increased rate of death. One solution is to perform live-donor renal transplantation after the depletion of donor-specific anti-HLA antibodies. Whether such antibody depletion results in a survival benefit as compared with waiting for an HLA-compatible kidney is unknown.

METHODS

We used a protocol that included plasmapheresis and the administration of low-dose intravenous immune globulin to desensitize 211 HLA-sensitized patients who subsequently underwent renal transplantation (treatment group). We compared rates of death between the group undergoing desensitization treatment and two carefully matched control groups of patients on a waiting list for kidney transplantation who continued to undergo dialysis (dialysis-only group) or who underwent either dialysis or HLA-compatible transplantation (dialysis-or-transplantation group).

RESULTS

In the treatment group, Kaplan-Meier estimates of patient survival were 90.6% at 1 year, 85.7% at 3 years, 80.6% at 5 years, and 80.6% at 8 years, as compared with rates of 91.1%, 67.2%, 51.5%, and 30.5%, respectively, for patients in the dialysis-only group and rates of 93.1%, 77.0%, 65.6%, and 49.1%, respectively, for patients in the dialysis-or-transplantation group (P<0.001 for both comparisons).

CONCLUSIONS

Live-donor transplantation after desensitization provided a significant survival benefit for patients with HLA sensitization, as compared with waiting for a compatible organ. By 8 years, this survival advantage more than doubled. These data provide evidence that desensitization protocols may help overcome incompatibility barriers in live-donor renal transplantation. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and the Charles T. Bauer Foundation.).

Center-level patterns of indicated willingness to and actual acceptance of marginal kidneys

UNet(SM) , the UNOS data collection and electronic organ allocation system, allows centers to specify organ offer acceptance criteria for patients on their kidney waiting list. We hypothesized that the system might not be fully utilized and that the criteria specified by most transplant centers would be much broader than the characteristics of organs actually transplanted by those centers. We analyzed the distribution of criteria values among waitlist patients (N = 304 385) between January 2000 and February 2009, mean criteria values among listed candidates on February 19, 2009 and differences between a center's specified criteria and the organs it accepted for transplant between July 2005 and April 2009. We found wide variation in use of criteria variables, with some variables mostly or entirely unused. Most centers specified very broad criteria, with little within-center variation by patient. An offer of a kidney with parameters more extreme than the maximum actually transplanted at that center was designated a 'surplus offer' and indicated a potentially avoidable delay in distribution. We found 7373 surplus offers (7.1% of all offers), concentrated among a small number of centers. The organ acceptance criteria system is currently underutilized, leading to possibly avoidable inefficiencies in organ distribution.

Eculizumab, bortezomib and kidney paired donation facilitate transplantation of a highly sensitized patient without vascular access

A 43-year-old patient with end-stage renal disease, a hypercoagulable condition and 100% panel reactive antibody was transferred to our institution with loss of hemodialysis access and thrombosis of the superior and inferior vena cava, bilateral iliac and femoral veins. A transhepatic catheter was placed but became infected. Access through a stented subclavian into a dilated azygos vein was established. Desensitization with two cycles of bortezomib was undertaken after anti-CD20 and IVIg were given. A flow-positive, cytotoxic-negative cross-match live-donor kidney at the end of an eight-way multi-institution domino chain became available, with a favorable genotype for this patient with impending total loss of a dialysis option. The patient received three pretransplant plasmapheresis treatments. Intraoperatively, the superior mesenteric vein was the only identifiable patent target for venous drainage. Eculizumab was administered postoperatively in the setting of antibody-mediated rejection and an inability to perform additional plasmapheresis. Creatinine remains normal at 6 months posttransplant and flow cross-match is negative. In this report, we describe the combined use of new agents (bortezomib and eculizumab) and modalities (nontraditional vascular access, splanchnic drainage of graft and domino paired donation) in a patient who would have died without transplantation.

Underutilization of hepatitis C-positive kidneys for hepatitis C-positive recipients

Hepatitis C-positive (HCV(+)) candidates likely derive survival benefit from transplantation with HCV(+) kidneys, yet evidence remains inconclusive. We hypothesized that lack of good survival benefit data has led to wide practice variation. Our goal was to characterize national utilization of HCV(+) kidneys for HCV(+) recipients, and to quantify the risks/benefits of this practice. Of 93,825 deceased donors between 1995 and 2009, HCV(+) kidneys were 2.60-times more likely to be discarded (p < 0.001). However, of 6830 HCV(+) recipients, only 29% received HCV(+) kidneys. Patients over 60 relative rate (RR 0.86), women (RR 0.73) and highly sensitized patients (RR 0.42) were less likely to receive HCV(+) kidneys, while African Americans (RR 1.56), diabetics (RR 1.29) and those at centers with long waiting times (RR 1.19) were more likely to receive them. HCV(+) recipients of HCV(+) kidneys waited 310 days less than the average waiting time at their center, and 395 days less than their counterparts at the same center who waited for HCV(-) kidneys, likely offsetting the slightly higher patient (HR 1.29) and graft loss (HR 1.18) associated with HCV(+) kidneys. A better understanding of the risks and benefits of transplanting HCV(+) recipients with HCV(+) kidneys will hopefully improve utilization of these kidneys in an evidence-based manner.

Increased risk of graft loss from hepatic artery thrombosis after liver transplantation with older donors

Hepatic artery thrombosis (HAT) is the most common vascular complication after liver transplantation; it has been reported to occur in 2% to 5% of liver transplant recipients. Most reports of HAT in the literature describe single-center series with small numbers of patients and lack the power to definitively identify nontechnical risk factors. We used the United Network for Organ Sharing database of adult deceased donor liver transplants from 1987 to 2006 to identify 1246 patients with graft loss from HAT. Univariate and multivariate regression analyses were performed to identify donor and graft risk factors for HAT-induced graft loss. Although most donor predictors of HAT-induced graft loss were surrogates for vessel size, donor age > 50 years was also a significant predictor of graft loss from HAT (relative risk = 1.45, P < 0.001). Furthermore, the risk of graft loss from HAT increased progressively with each decade of donor age > 50 years, such that a 61% increased risk of HAT-related graft loss (relative risk = 1.61, P < 0.001) was associated with donor age > 70 years. A separate analysis of risk factors for early HAT graft loss (<or=90 days) and late HAT graft loss (> 90 days) found that older donor age was associated with increased late HAT graft loss. These findings are of interest in an era of ongoing organ shortages requiring maximum utilization of potential allografts and increasing allocation of older allografts.

Histidine-tryptophan-ketoglutarate (HTK) is associated with reduced graft survival of deceased donor kidney transplants

Single-center studies have reported equivalent outcomes of kidney allografts recovered with histidine-tryptophan-ketoglutarate (HTK) or University of Wisconsin (UW) solution. However, these studies were likely underpowered and often unadjusted, and multicenter studies have suggested HTK preservation might increase delayed graft function (DGF) and reduce graft survival of renal allografts. To further inform clinical practice, we analyzed the United Network for Organ Sharing (UNOS) database of deceased donor kidney transplants performed from July 2004 to February 2008 to determine if HTK (n = 5728) versus UW (n = 15 898) preservation impacted DGF or death-censored graft survival. On adjusted analyses, HTK preservation had no effect on DGF (odds ratio [OR] 0.99, p = 0.7) but was associated with an increased risk of death-censored graft loss (hazard ratio [HR] 1.20, p = 0.008). The detrimental effect of HTK was a relatively late one, with a strong association between HTK and subsequent graft loss in those surviving beyond 12 months (HR 1.43, p = 0.007). Interestingly, a much stronger effect was seen in African-American recipients (HR 1.55, p = 0.024) than in Caucasian recipients (HR 1.18, p = 0.5). Given recent studies that also demonstrate that HTK preservation reduces liver and pancreas allograft survival, we suggest that the use of HTK for abdominal organ recovery should be reconsidered.

Kidney transplantation in previous heart or lung recipients

Outcomes after heart and lung transplants have improved, and many recipients survive long enough to develop secondary renal failure, yet remain healthy enough to undergo kidney transplantation. We used national data reported to United Network for Organ Sharing (UNOS) to evaluate outcomes of 568 kidney after heart (KAH) and 210 kidney after lung (KAL) transplants performed between 1995 and 2008. Median time to kidney transplant was 100.3 months after heart, and 90.2 months after lung transplant. Renal failure was attributed to calcineurin inhibitor toxicity in most patients. Outcomes were compared with primary kidney recipients using matched controls (MC) to account for donor, recipient and graft characteristics. Although 5-year renal graft survival was lower than primary kidney recipients (61% KAH vs. 73.8% MC, p < 0.001; 62.6% KAL vs. 82.9% MC, p < 0.001), death-censored graft survival was comparable (84.9% KAH vs. 88.2% MC, p = 0.1; 87.6% KAL vs. 91.8% MC, p = 0.6). Furthermore, renal transplantation reduced the risk of death compared with dialysis by 43% for KAH and 54% for KAL recipients. Our findings that renal grafts function well and provide survival benefit in KAH and KAL recipients, but are limited in longevity by the general life expectancy of these recipients, might help inform clinical decision-making and allocation in this population.

The fate of anti-HLA antibody among renal transplantation recipients treated with bortezomib

We present four cases of renal transplant recipients who were treated with bortezomib for four different indications, each of whom had circulating anti-HLA antibodies that were followed serially throughout their courses of bortezomib therapy. It is important to note that each patient was administered bortezomib in conjunction with other agents and therapies traditionally used for desensitization or the treatment of AMR. The results have been mixed. In some cases substantial decreases in HLA-antibody were temporally related to bortezomib therapy. In the one case of recalcitrant AMR there has been no reduction in DSA after 2 cycles of the drug. Bortezomib has been well tolerated. One patient developed reversible peripheral neuropathic pain while another experienced line sepsis, a urinary tract infection, and an invasive fungal skin infection. Again, this patient had also received protracted courses of plasmapheresis combined with T-cell and B-cell depleting agents. The use of these other drugs precludes the ability to rigorously evaluate the efficacy of bortezomib in isolation and points towards a need for large-scale, controlled trials to determine whether the drug's promising mechanism of action is applicable in the setting of solid organ transplantation.

Histidine-tryptophan-ketoglutarate (HTK) is associated with reduced graft survival in pancreas transplantation

Prior single-center studies have reported that pancreas allograft survival is not affected by preservation in histidine-tryptophan-ketoglutarate (HTK) versus University of Wisconsin (UW) solution. To expand on these studies, we analyzed the United Network for Organ Sharing (UNOS) database of pancreas transplants from July 2004, through February 2008, to determine if preservation with HTK (N = 1081) versus UW (N = 3311) impacted graft survival. HTK preservation of pancreas allografts increased significantly in this time frame, from 15.4% in 2004 to 25.4% in 2008. After adjusting for other recipient, donor, graft and transplant center factors that impact graft survival, HTK preservation was independently associated with an increased risk of pancreas graft loss (hazard ratio [HR] 1.30, p = 0.014), especially in pancreas allografts with cold ischemia time (CIT) >or=12 h (HR 1.42, p = 0.017). This reduced survival with HTK preservation as compared to UW preservation was seen in both simultaneous pancreas-kidney (SPK) transplants and pancreas alone (PA) transplants. Furthermore, HTK preservation was also associated with a 1.54-fold higher odds of early (<30 days) pancreas graft loss as compared to UW (OR 1.54, p = 0.008). These results suggest that the increasing use of HTK for abdominal organ preservation should be re-examined.

Pharmacotherapy Before and After Revascularization: Anticoagulation, Antiplatelet Agents, and Statins

Proper medical management may enhance perioperative and long-term outcomes for patients with peripheral arterial disease (PAD). For patients with PAD, aspirin and statin drugs remain the mainstay of medical management, based on results from multiple randomized clinical trials that have demonstrated improvements in long-term survival and a decrease in cardiovascular events with these agents. There may additional, unintended positive consequences of treatment with statin drugs, including potential improvements in symptoms of claudication and enhanced graft patency after infrainguinal bypass. For patients undergoing surgical or endovascular revascularization, aspirin remains the standard of care for antithrombotic therapy. Beyond this, use of warfarin should be reserved for patients with high-risk surgical bypass grafts to prolong graft patency, because it carries a significant risk of bleeding complications. The utility of clopidogrel after surgical and endovascular infrainguinal revascularization remains undefined but warrants additional study. At this time the only clear indication for clopidogrel in patients with infrainguinal arterial occlusive disease is for PAD patients who are intolerant of aspirin or have a history of coronary artery stenting within the past 6 months. Proper adjunctive pharmacotherapy for the patient with PAD has the potential to improve symptoms, graft patency, and survival in this challenging subset of patients.

Presenilin regulates capacitative calcium entry dependently and independently of gamma-secretase activity

Mutations in presenilin-1 and 2 (PS) lead to increased intracellular calcium stores and an attenuation in the refilling mechanism known as capacitative calcium entry (CCE). Previous studies have shown that the mechanism by which PS modulates intracellular calcium signaling is dependent on gamma-secretase activity. Although the modulation of intracellular calcium signaling can lead to alterations in CCE, it is plausible that PS can also directly affect CCE independent of the effect it exerts on intracellular stores. To investigate this possibility, we studied the effects of the dominant negative variant of PS1 known as DeltaTM1-2, which lacks the first two transmembrane domains of PS1 and in which gamma-secretase activity is abrogated. We demonstrate that, like other dominant negative isoforms of PS1, DeltaTM1-2 expression leads to reduced intracellular calcium. However, unlike other dominant negative isoforms, DeltaTM1-2 leads to a deficit rather than a potentiation of CCE. These data suggest that changes in the structural components of presenilin can modulate CCE independent of its function in gamma-secretase activity and intracellular calcium stores.