J. Pavlovic

Zoledronic Acid Prevents Bone Loss after Liver Transplantation: A Randomized, Double-Blind, Placebo-Controlled Trial

Context Rapid bone loss occurs in the first few months after liver transplantation and may be associated with fractures. Contribution This randomized, double-blind trial found that infusing zoledronic acid within 1 week of liver transplantation and again 1, 3, 6, and 9 months after transplantation prevented bone loss more effectively than did placebo infusions. Differences between groups lessened over time as some patients receiving placebo regained bone after several months. Zoledronic acid sometimes caused postinfusion hypocalcemia and temporary secondary hyperparathyroidism. Cautions The trial was not powered to assess differences in fracture outcomes. Implications Zoledronic acid infusions can prevent bone loss after liver transplantation. The Editors Osteoporosis is a frequent complication of end-stage liver disease of various causes. Initially described in patients with cholestatic liver disease (1-4), it also occurs in association with cirrhosis secondary to hepatitis B and C virus infection and alcohol abuse (5-8). Although contributing factors that are common to postmenopausal osteoporosis have been identified, such as age, gonadal status, and vitamin D deficiency, cirrhosis is an independent risk factor for osteoporosis (8, 9). Some patients with cirrhosis eventually need liver transplantation, a procedure that is associated with accelerated bone loss, particularly within the first 3 to 6 months (10-13). Investigators report fractures rates of 16% to 40% during this period, predominantly of the vertebrae and ribs (12-16). Pain and restricted mobility after a fracture delay rehabilitation of patients and are severe enough at times to require hospitalization. It is not clear whether bisphosphonate drugs, which inhibit osteoclast-mediated bone resorption, reverse bone loss after transplantation. One uncontrolled study reported variable results (17). A recent controlled study, however, did not find any benefit of intravenous pamidronate in liver transplant recipients who had unusually little acute post-transplantation bone loss and few fractures in both the treatment and control groups (18). In our experience, bone disease and fractures after transplantation are major problems. Thus, we performed a randomized, double-blind, placebo-controlled trial of a potent intravenous bisphosphonate, zoledronic acid, in patients undergoing liver transplantation. The primary end point was bone density change at 3 months after transplantation; secondary end points were bone density change at 12 months and biochemical variables of bone turnover. Methods Setting and Patients From July 2000 to July 2003, we recruited adults undergoing transplantation for chronic liver disease from 2 large transplantation centers within the Australian and New Zealand Liver Transplant program. We based recruitment primarily on convenience for individuals, including whether they resided close to the transplantation center and were not already taking part in other research studies. We excluded patients if they had a serum creatinine level greater than 1.5 times the upper limit of normal (for example, >165 mol/L [>1.86 mg/dL]), had had treatment within the previous 12 months with agents known to affect bone metabolism (bisphosphonates, calcitriol, or sex hormones), or had hypocalcemia (corrected serum calcium level <2.2 mmol/L [<8.8 mg/dL]). We discussed the study and obtained written informed consent from patients at their pretransplantation assessment. After transplantation, just before the first infusion, we asked the patients to verbally re-consent. Recruited patients were similar to adult patients in the Australian Liver Transplant Database (www.cs.nsw.gov.au/gastro/livertransplant) with respect to age, sex, ChildPugh score, and cause of cirrhosis. The ethics review committees at both institutions approved the study protocol. Randomization and Interventions As soon as was feasible after liver transplantation, patients were randomly assigned centrally to receive zoledronic acid or placebo. Random assignment was done by using the method of stratified minimization (19) on the basis of the following variables: age, sex, baseline bone mineral density (BMD), and primary immunosuppressive therapy (cyclosporine or tacrolimus). Of note, all but 4 patients were recruited from 1 center; these 14 patients were randomly allocated to 2 per treatment group. Hospital pharmacists prepared infusions and coded them to maintain blinding. Five infusions of zoledronic acid (4 mg in 100 mL of normal saline, administered over 15 minutes) or saline were given over a 12-month period. The first infusion was administered within 7 days of liver transplantation and then again at months 1, 3, 6, and 9 after transplantation. All patients received calcium carbonate, 600 mg/d, and vitamin D supplementation (ergocalciferol, 1000 U/d) from the time of transplantation listing and throughout the study. The standard immunosuppression regimen after transplantation at both centers consisted of tacrolimus or cyclosporine, azathioprine, and methylprednisolone at 500 mg on day 1, decreasing to 20 mg by day 12. Alternative immunosuppressive therapy included the use of mycophenolate instead of azathioprine in some patients. Biopsy-proven cellular rejection was treated with pulses of methylprednisolone, 1000 mg/d for 3 days, followed by reduced doses of prednisone similar to those used after transplantation, aiming to reach a prednisone dosage of 20 mg/d by day 14. Assessments and Follow-up Before transplantation, baseline data, including the ChildPugh score, were re-collected every 6 months (designated as time 0 months). Bone mineral density at L2 to L4 of the lumbar spine, femoral neck, and total hip was measured by using dual x-ray absorptiometry on a Prodigy densitometer (Lunar, Madison, Wisconsin) in both centers at baseline and at months 3, 6, and 12 after transplantation. In vitro and in vivo coefficients of variation for BMD at the lumbar spine, hip, spine, and total body were less than 1.0 and less than 2.0%, respectively. The BMD data were expressed as T-scores (that is, SDs removed from the average BMD of young healthy controls) using the North American reference ranges provided by the densitometer manufacturer. Radiographs of the thoracolumbar spine were taken at the baseline assessment and at 12 months after transplantation. New vertebral fractures were identified by radiology report. Blood and urine samples were collected in the morning at the pretransplantation assessment and were subsequently taken every 6 months until liver transplantation and at months 1, 3, 6, 9, and 12 months after transplantation. Serum testosterone levels (in men), parathyroid hormone (PTH) levels, and urinary free deoxypyridinoline levels, corrected for creatinine, were measured on the Immulite 2000 autoanalyzer (Diagnostic Products Corp., Los Angeles, California). Both 25- and 1,25-hydroxyvitamin D levels were measured by radioimmunoassay (Diasorin, Stillwater, Minnesota) after an initial extraction from serum with acetonitrile and a second solvent column extraction step for 1,25-hydroxyvitamin D. Serum levels of insulin-like growth factor I were measured by using a double antibody radioimmunoassay after acidethanol extraction (Bioclone, New South Wales, Australia). The coefficients of variation, measured at 2 levels, were less than 8% for total testosterone, intact PTH, and 25- and 1,25-hydroxyvitamin D; less than 11.0% for insulin-like growth factor I; and 17.7% and 6.9% for urinary deoxypyridinoline at 27 nmol/L and 107 nmol/L, respectively. Bone-specific alkaline phosphatase (ALP) was measured by using competitive immunocapture assay on an Access analyzer (Beckman Coulter, Inc., Fullerton, California). Adverse events were assessed at each follow-up point by open-ended questions asked by the treating physician and by review of charts by the research nurse. Physicians and nurses were blinded to treatment group. Physicians rated events as expected or unexpected and assessed potential attribution to therapy. Fractures or renal impairment and serum creatinine levels greater than 165 mol/L (>1.86 mg/dL) resulted in discontinuation of therapy. Hypocalcemia (corrected serum calcium) was graded according to the following criteria: grade 1, 1.90 to 2.14 mmol/L (7.6 to 8.6 mg/dL); grade 2, 1.70 to 1.89 mmol/L (6.8 to 7.6 mg/dL); grade 3, 1.50 to 1.69 mmol/L (6.0 to 6.8 mg/dL); and grade 4, less than 1.50 mmol/L (<6.0 mg/dL). Statistical Analysis The primary end points of change in BMD at 3 months for the hip and the lumbar spine were used as the basis for a priori sample size calculations. On the basis of a 10% difference in BMD change, a 2-tailed P value of 0.05, and 80% power, 34 patients per group were required. Anticipating a 10% noncompletion rate, we estimated that 75 patients would need to be recruited. Linear mixed-effects models were fitted to BMD at the lumbar spine, femoral neck, and total hip and to biochemical data. Treatment (zoledronic acid or placebo), time, and their 2-way interaction were considered as fixed effects, as were the baseline body weight, serum PTH level, and testosterone level (in men). These baseline variables showed some imbalance between treatment groups. Differences between treatments were estimated as both unadjusted and adjusted for potential confounding variables, baseline weight, and serum PTH level. Because estimates of treatment differences in men further adjusted for testosterone changed by less than 10%, this covariate was not included in any final models. All tabulated results refer to men and women combined. The unadjusted treatment differences are based on intention-to-treat analyses of all 62 patients. Because 10 patients had missing baseline weight or serum PTH measurements, the adjusted analyses represent modified intention-to-treat analyses of the remaining 52 patients. Unadjusted and adjusted treatment differences for the percentage change in BMD fro

Targeted individual prophylaxis offers superior risk stratification for cytomegalovirus reactivation after liver transplantation

Cytomegalovirus (CMV) can reactivate following liver transplantation. Management of patients currently considered low risk based on pretransplant serology remains contentious, with universal prophylaxis and preemptive strategies suffering from significant deficiencies. We hypothesized that a CMV‐specific T cell assay performed early after transplant as part of a preemptive strategy could better stratify “low‐risk” (recipient seropositive) patients. We conducted a prospective, blinded, observational study in 75 adult recipients. QuantiFERON‐cytomegalovirus was performed both before and at multiple times after transplant. Low‐risk patients (n = 58) were monitored as per unit protocol and treatment was commenced if CMV > 1000 copies/mL (DNAemia). Twenty patients needed antiviral treatment for other reasons and were censored (mainly for rejection or herpes simplex virus infection); 19/38 (50%) of the remaining low‐risk patients developed DNAemia at mean 34.6 days after transplant. A week 2 result of <0.1 IU/mL was significantly associated with risk of subsequent DNAemia (hazard ratio [HR], 6.9; P = 0.002). The positive predictive value of 80% suggests these patients are inappropriately labeled low risk and are actually at high likelihood of CMV reactivation. A secondary cutoff of <0.2 IU/mL was associated with moderate risk (HR, 2.8; P = 0.01). In conclusion, a protocol based on a single early CMV‐specific T cell based assay would offer improved risk stratification and individualization of patient management after transplant. This could offer improved drug and service utilization and potentially result in significant improvements over both currently used protocols to manage supposedly low‐risk patients. Liver Transpl 21:1478‐1485, 2015.

Viral factors influencing the outcome of human cytomegalovirus infection in liver transplant recipients

BACKGROUND Cytomegalovirus (CMV) remains the leading viral cause of disease following orthotopic liver transplantation (OLT) despite the availability of antiviral agents for prophylaxis and therapy. OBJECTIVE Examine the viral factors that influence the outcome of CMV infection following valganciclovir prophylaxis or laboratory-guided preemptive therapy in OLT recipients. STUDY DESIGN The value of valganciclovir prophylaxis and laboratory-guided preemptive therapy for the prevention of CMV infection and disease was observed in 64 OLT recipients. Prophylaxis was given to all CMV seronegative recipients receiving a liver from a seropositive donor (D+R-; n=15), and all other recipients were randomised to receive either prophylaxis (n=24) or laboratory-guided preemptive therapy (n=25). Recipients were monitored for CMV DNAemia, viral load, emergence of antiviral resistant strains and co-infections. RESULTS CMV end-organ disease and antiviral resistant strains only occurred in D+R- recipients despite the use of prophylaxis in these patients. The D+R- recipients commencing prophylaxis immediately following transplantation had better outcomes compared to those for whom prophylaxis was delayed due to renal impairment. Prophylaxis reduced the incidence of CMV DNAemia, persistent infection, and high viral loads for CMV seropositive (D-R+and D+R+) recipients, but laboratory-guided preemptive therapy effectively controlled CMV infection and prevented disease in these OLT recipients. CONCLUSION Delaying the commencement of valganciclovir prophylaxis may be associated with worse outcomes for high-risk OLT recipients. Laboratory-guided pre-emptive therapy remains an alternative approach for seropositive recipients at lower risk of CMV disease.

Electronic Estimations of Renal Function Are Inaccurate in Solid-Organ Transplant Recipients and Can Result in Significant Underdosing of Prophylactic Valganciclovir

ABSTRACT In a prospective study of solid-organ transplant recipients (n = 22; 15 hepatic and 7 renal) receiving valganciclovir for cytomegalovirus (CMV) prophylaxis, electronic estimation of glomerular filtration rate (eGFR) underestimated the true GFR (24-h urine creatinine clearance) by >20% in 14/22 (63.6%). Its use was associated with inappropriate underdosing of valganciclovir, while the Cockroft-Gault equation was accurate in 21/22 patients (95.4%). Subtherapeutic ganciclovir levels (≤0.6 mg/liter) were common, occurring in 10/22 patients (45.4%); 7 had severely deficient levels (<0.3 mg/liter).

A novel immune function biomarker identifies patients at risk of clinical events early following liver transplantation

Balancing immunosuppression after liver transplant is difficult, with clinical events common. We investigate whether a novel immune biomarker based on a laboratory platform with widespread availability that measures interferon γ (IFNγ) after stimulation with a lyophilized ball containing an adaptive and innate immune stimulant can predict events following transplantation. A total of 75 adult transplant recipients were prospectively monitored in a blinded, observational study; 55/75 (73.3%) patients experienced a total of 89 clinical events. Most events occurred within the first month. Low week 1 results were significantly associated with risk of early infection (area under the receiver operating characteristic curve [AUROC], 0.74; P = 0.008). IFNγ ≤ 1.30 IU/mL (likelihood ratio positive, 1.93; sensitivity, 71.4%; specificity, 63.0%) was associated with the highest risk for infection with minimal rejection risk. Nearly half the cohort (27/60, 45.0%) expressed IFNγ ≤ 1.30 IU/mL. Moreover, an elevated week 1 result was significantly associated with the risk of rejection within the first month after transplant (AUROC, 0.77; P = 0.002), but no episodes of infection. On multivariate logistic regression, IFNγ ≥ 4.49 IU/mL (odds ratio, 4.75) may be an independent predictor of rejection (P = 0.05). In conclusion, low IFNγ suggesting oversuppression is associated with infections, whereas high IFNγ indicating undersuppression is associated with rejection. This assay offers the potential to allow individualization and optimization of immunosuppression that could fundamentally alter the way patients are managed following transplantation. Liver Transplantation 23 487–497 2017 AASLD.

Early viral-specific T-cell testing predicts late cytomegalovirus reactivation following liver transplantation

Although antiviral prophylaxis is effective in preventing early cytomegalovirus (CMV) reactivation following liver transplantation (OLT), it predisposes patients to late CMV after prophylaxis has ceased. QuantiFERON–CMV (QFN‐CMV, Qiagen, The Netherlands) measures an individuals viral‐specific immune response.