Secondary Osteoporosis in Liver Transplant Recipients: a Longitudinal Study in Patients With and Without Cholestatic Liver Disease

Predictors for pathological bone fractures in children undergoing liver transplantation: A retrospective cohort study

BACKGROUND

Hepatic osteodystrophy refers to bone disorders associated with chronic liver disease, including children undergoing liver transplantation (LT). The aim of this study was to quantify the prevalence of pathological fractures (PF) in children before and after LT and to identify associated factors for their occurrence.

METHODS

Children aged 0-18 years who underwent LT from 1/2005 to 12/2020 were included in this retrospective study. Data on patient demographics, types and anatomical locations of fracture and biological workups were extracted. Variables were assessed at 3 time points: T - 1 at the moment of listing for LT; T0 at the moment of LT and T + 1 at 1-year post-LT.

RESULTS

A total of 105 children (49 [47%] females) were included in this study. Median age at LT was 19 months (range 0-203). Twenty-two patients (21%) experienced 65 PF, 11 children before LT, 10 after LT, and 1 before and after LT. The following variables were observed as associated with PF: At T - 1, low weight and height z-scores, and delayed bone age; at T0, low weight and height z-scores, high total and conjugated bilirubin; at T + 1, persistent low height z-score. Patients in the PF-group were significantly more under calcium supplementation and/or nutritional support at T - 1, T0 and T + 1.

CONCLUSION

More than one in five children needing LT sustain a PF before or after LT. Patients with low weight and height z-scores and delayed bone age are at increased risk for PF. Nutritional support remains important, even if to date it cannot fully counteract the risks of PF.

Complications in Post-Liver Transplant Patients

Liver transplantation (LT) is the treatment of choice for liver failure and selected cases of malignancies. Transplantation activity has increased over the years, and indications for LT have been widened, leading to organ shortage. To face this condition, a high selection of recipients with prioritizing systems and an enlargement of the donor pool were necessary. Several authors published their case series reporting the results obtained with the use of marginal donors, which seem to have progressively improved over the years. The introduction of in situ and ex situ machine perfusion, although still strongly debated, and better knowledge and treatment of the complications may have a role in achieving better results. With longer survival rates, a significant number of patients will suffer from long-term complications. An extensive review of the literature concerning short- and long-term outcomes is reported trying to highlight the most recent findings. The heterogeneity of the behaviors within the different centers is evident, leading to a difficult comparison of the results and making explicit the need to obtain more consent from experts.

Changes in Serum Bone Metabolism Markers after Living Donor Liver Transplantation (LDLT) and Their Association with Fracture Occurrences

Living donor liver transplantation (LDLT) is lifesaving, but can lead to osteoporosis and fractures. In our 3-year study of 25 LDLT recipients, we observed significant reductions in lumbar spine and femoral neck T scores, along with bone resorption marker reductions and liver regeneration marker increases. Serum calcium levels increased, while osteoprotegerin (OPG) decreased and Dickkopf-related protein 1 (DKK-1) increased. Patients who suffered fractures within 3 years of LDLT had higher serum OPG, lower serum nuclear factor kappa B ligand (RANKL), a higher OPG/RANKL ratio and higher serum DKK-1 levels. OPG, RANKL, OPG/RANKL ratio and DKK-1 levels before LDLT predicted hip or spine fractures within three years after LDLT. Further research is necessary to determine the optimal level of osteoclastic activity for preventing fracture onset.

Increased Imminent Fracture Risk in Liver Transplant Recipients Despite Bisphosphonate Therapy

BACKGROUND

Bone loss is significant after orthotopic liver transplant (OLT) and is associated with increased fracture risk and decreased quality of life. In post-transplant fracture prevention, the cornerstone of therapeutic management is bisphosphonates.

METHODS

We conducted a retrospective study in a cohort of 155 OLT recipients who received a bisphosphonate prescription at hospital discharge between 2012 and 2016 to investigate post-OLT fragility fracture incidence and predictive risk factors.

RESULTS

Before OLT, 14 patients presented a T score < -2.5 SD, and 23 patients (14.8%) had a history of fracture. During follow-up, the cumulative incidence of fractures on bisphosphonates (99.4% risedronate/alendronate) was 9.7% at 12 months and 13.1% at 24 months. The median time to first fragility fracture was 10 months (IQR, 3-22 months) and thus within the first 2 years of follow-up. Predictive factors of fragility fractures in multivariate Cox regression analyses included age 60 years or older (hazard ratio [HR], 2.61; 95% CI, 1.14-6.01; P = .02), post-transplant diabetes mellitus (HR, 3.82; 95% CI, 1.55-9.44; P = .004), and cholestatic disease (HR, 5.93; 95% CI, 2.30-15.26; P = .0002). Additionally, the female sex was associated with a strong trend toward increased fracture risk in univariate analysis (HR, 2.27; 95% CI, 1.00-5.15; P = .05), as well as a post-transplant absolute decrease in bone mineral density at the femoral neck and total hip (P = .08).

CONCLUSIONS

This real-world study reports a high incidence of fractures post-OLT despite bisphosphonate therapy. Age 60 years or older, post-transplant diabetes mellitus, cholestatic disease, female sex, and femoral neck and/or total hip bone mineral density loss contribute to increased imminent fracture risk in liver transplant recipients.

Liver Transplantation for Primary Biliary Cholangitis

Despite a significant increase in the total number of liver transplants (LTs) performed over the last 3 decades, primary biliary cholangitis (PBC) has become an uncommon indication for LT, which likely reflects the benefits of earlier diagnosis and available treatment, such as ursodeoxycholic acid (UDCA). Nonetheless, LT remains the only cure for patients with progressive PBC despite medical therapy with survival rates that are among the highest of all indications for LT. Post-LT PBC patients, however, are at increased risk of rejection and disease recurrence.

Pretransplant Evaluation and Liver Transplantation Outcome in PBC Patients

Primary biliary cholangitis (PBC) is an autoimmune chronic cholestatic liver disease characterized by progressive cholangiocyte and bile duct destruction leading to fibrosis and finally to liver cirrhosis. The presence of disease-specific serological antimitochondrial antibody (AMA) together with elevated alkaline phosphatase (ALP) as a biomarker of cholestasis is sufficient for diagnosis. Ursodeoxycholic acid (UDCA) is the first treatment option for PBC. Up to 40% of patients have an incomplete response to therapy, and over time disease progresses to liver cirrhosis. Several risk scores are proposed for better evaluation of patients before and during treatment to stratify patients at increased risk of disease progression. GLOBE score and UK PBC risk score are used for the evaluation of UDCA treatment and Mayo risk score for transplant-free survival. Liver transplantation (LT) is the only treatment option for end-stage liver disease. More than 10 years after LT, 40% of patients experience recurrence of the disease. A liver biopsy is required to establish rPBC (recurrent primary biliary cholangitis). The only treatment option for rPBC is UDCA, and data show biochemical and clinical improvement, plus potential beneficial effects for use after transplantation for the prevention of rPBC development. Additional studies are required to assess the full impact of rPBC on graft and recipient survival and for treatment options for rPBC.

Osteosarcopenia in autoimmune cholestatic liver diseases: Causes, management, and challenges

Primary biliary cholangitis and primary sclerosing cholangitis (PSC) are the most common cholestatic liver diseases (CLD) in adults and are both characterized by an immune pathogenesis. While primary biliary cholangitis is a model autoimmune disease, with over 90% of patients presenting very specific autoantibodies against mitochondrial antigens, PSC is considered an immune mediated disease. Osteoporosis is the most common bone disease in CLD, resulting in frequent fractures and leading to significant morbidity. Further, sarcopenia is emerging as a frequent complication of chronic liver diseases with a significant prognostic impact and severe implications on the quality of life of patients. The mechanisms underlying osteoporosis and sarcopenia in CLD are still largely unknown and the association between these clinical conditions remains to be dissected. Although timely diagnosis, prevention, and management of osteosarcopenia are crucial to limit the consequences, there are no specific guidelines for management of osteoporosis and sarcopenia in patients with CLD. International guidelines recommend screening for bone disease at the time of diagnosis of CLD. However, the optimal monitoring strategies and treatments have not been defined yet and vary among centers. We herein aim to comprehensively outline the pathogenic mechanisms and clinical implications of osteosarcopenia in CLD, and to summarize expert recommendations for appropriate diagnostic and therapeutic approaches.

Bone mineral density following liver transplantation: a 10-year trend analysis

We evaluated the prevalence of osteoporosis and annual changes in bone mineral density (BMD) over 10 years post-liver transplantation. BMD in the lumbar spine improved significantly post-transplantation, reaching a 12% increase at year 10. In contrast, BMD in the femoral neck and hip deteriorated and did not return to baseline levels.

INTRODUCTION

This study (1) evaluated the prevalence of osteoporosis, and the annual changes in bone mineral density (BMD) over 10 years, and (2) identified the risk factors for worsened BMD in stable liver transplant recipients (LTRs).

METHODS

LTRs who underwent liver transplantation (LT) at Singapore General Hospital between February 2006 and Mar 2019 were included. Demographic, clinical data, and BMD in the lumbar spine (LS), femoral neck (FN), and total hip (TH) were collected retrospectively from the medical records.

RESULTS

Eighty-three patients (mean age: 55 ± 8 years) with a median follow-up of 80 months were included. The prevalence of osteoporosis increased significantly from 18.1% pre-LT to 34.3% post-LT (p = 0.021), and the incidence of osteoporosis was 18.2%. Worsened BMD (normal to osteopenia/osteopenia to osteoporosis) was found in 27.2% of LTRs. No significant risk factors were associated with worsened BMD, but females had a trend towards a higher odd (adjusted odds ratio: 3.54, 95%CI (0.61-20.5), p = 0.159). The LS BMD increased within 6-month post-LT and continued to improve throughout the entire follow-up period. In contrast, BMD in the FN and TH deteriorated and did not return to baseline levels post-LT.

CONCLUSION

Prevalence of osteoporosis increased significantly post-LT. Over a 10-year follow-up, 27.2% of LTRs had worsened BMD status, and a possible risk factor may be female gender. While the LS BMD improved with time, the BMD in the FN and TH persisted below baseline throughout the follow-up period. Future studies should explore long-term therapies to improve BMD in the FN and TH post-LT.

Bone Health in Patients With Liver Diseases

Osteoporosis is the most common bone disease in chronic liver disease (CLD) resulting in frequent fractures and leading to significant morbidity in this population. In addition to patients with cirrhosis and chronic cholestasis, patients with CLD from other etiologies may be affected in the absence of cirrhosis. The mechanism of osteoporosis in CLD varies according to etiology, but in cirrhosis and cholestatic liver disease it is driven primarily by decreased bone formation, which differs from the increased bone resorption seen in postmenopausal osteoporosis. Direct toxic effects from iron and alcohol play a role in hemochromatosis and alcoholic liver disease, respectively. Chronic inflammation also has been proposed to mediate bone disease in viral hepatitis and nonalcoholic fatty liver disease. Treatment trials specific to osteoporosis in CLD are small, confined to primary biliary cholangitis and post-transplant patients, and have not consistently demonstrated a benefit in this population. As it stands, prevention of osteoporosis in CLD relies on the mitigation of risk factors such as smoking and alcohol use, treatment of underlying hypogonadism, and encouraging a healthy diet and weight-bearing exercise. The primary medical intervention for the treatment of osteoporosis in CLD remains bisphosphonates though a benefit in terms of fracture reduction has never been shown. This review outlines what is known regarding the pathogenesis of bone disease in CLD and summarizes current and emerging therapies.

Osteoporosis in Primary Biliary Cholangitis: Prevalence, Impact and Management Challenges

Primary biliary cholangitis (PBC) is a chronic, cholestatic condition associated with symptoms that directly impact the quality of life in those afflicted with the disease. In addition to pruritus and fatigue, patients with PBC may develop metabolic bone disease from reduced bone density, such as osteopenia and osteoporosis. Osteoporosis increases the risk of fractures, as well as morbidity and mortality. The prevalence of osteoporosis in PBC is expected to increase in conjunction with the rising prevalence of PBC as a whole. Timely diagnosis, prevention and management of osteoporosis are crucial in order to optimize the quality of life. There is a paucity of data evaluating the management of osteoporosis in PBC. The optimal timing for diagnosis and monitoring is not yet established and is guided by expert opinion. National guidelines recommend screening for osteoporosis at the time of diagnosis of PBC. Monitoring strategies are based on results of initial screening and individual risk factors for bone disease. Identifying reduced bone density is imperative to institute timely preventive and treatment strategies. However, treatment remains challenging as efficacious therapies are currently lacking. The data on treatment of osteoporosis in PBC are mostly extrapolated from postmenopausal osteoporosis literature. However, this data has not directly translated to useful treatment strategies for PBC-related osteoporosis, partly because of the different pathophysiological mechanisms of the two diseases. The lack of useful preventive measures and efficacious treatment strategies remains the largest pitfall that challenges the management of patients with PBC. In this review, we comprehensively outline the epidemiology, clinical implications and challenges, as well as management strategies of PBC-related osteoporosis.

Osteoporosis in liver disease: pathogenesis and management

Osteoporosis affects a substantial proportion of patients with chronic liver disease. Pathologic fracture in osteoporosis significantly affects quality of life and life expectancy. By some estimates, 40% of patients with chronic liver disease may experience osteoporotic fracture. In this study we review the pathogenesis, diagnosis and treatment of specific liver disease entities and their relation to osteoporosis.

Osteoporosis in men

Osteoporosis in men causes significant morbidity and mortality. Bone health declines gradually, often insidiously; and in light of the advancing aging population poses a serious public health issue that is not well recognized. Studies of the past decade have expanded our understanding of the events within, as well as the regulation of, bone remodeling and provided better insight into the physiology and pathophysiology specific to the adult male skeleton. The clinical measurement of bone mineral density using dual-energy X-ray absorptiometry remains the gold standard for diagnosis of osteoporosis in males; and fracture risk assessment is now recognized as a preferred approach to guide treatment decisions. Utilizing surrogate end-points such as increasing bone mineral density and decreasing concentrations of bone resorption markers, clinical trials have demonstrated efficacy in pharmacological treatment of osteoporosis in the adult male. Unfortunately, few studies have evaluated the anti-fracture benefits in this population. Measurement of bone turnover markers may be an additional tool to monitor therapeutic responsiveness in addition to the measurement of bone mineral density.

Bone disease in patients awaiting liver transplantation. Has the situation improved in the last two decades?

In recent years, there has been speculation about the possibility of a reduction in the incidence of fractures after liver transplantation (LT) because of changes in the characteristics of candidates and the use of different immunosuppressive therapies. We analyzed the characteristics of LT candidates (CTC) and compared them with historical data from a group of LT candidate patients (HTC). Data from 60 CTC patients consecutively included in a screening program of metabolic bone disease were compared with data from 60 HTC patients prospectively evaluated between 1992 and 1993. In all patients, we analyzed the clinical and laboratory characteristics, bone mineral density (BMD) dual-energy X-ray absorptiometry, and skeletal fractures. Patients in the CTC group were older than patients in the HTC group. The CTC group had lower femoral neck T scores. No differences were observed between groups in the proportion of patients with osteoporosis (22 vs. 30 %, p = ns) or fractures (36 vs. 33 %, p = ns). The percentage of patients with normal BMD decreased from 38 to 20 %. 25(OH)D values were low in both groups. Only 7.5 % of the CTC patients received calcium and/or vitamin D supplementation. The prevalence of fractures among CTC patients was similar to that seen two decades ago. At present, candidates for LT are older and have lower femoral bone mass. Vitamin D deficiency remains frequent; however, calcium and/or vitamin D supplementation is uncommon.

Treatment of osteoporosis in patients with chronic liver disease and in liver transplant recipients

The pathogenesis of osteoporosis in chronic liver disease and post-liver transplantation is complex and heterogeneous. The development of hepatic osteodystrophy may be related to both increased bone resorption and decreased bone formation. Available medical treatments can be broadly classified into antiresorptive and bone-stimulating agents. Most published studies on the treatment of osteoporosis in patients with liver disease have used the commonly prescribed antiosteoporosis drugs approved for postmenopausal osteoporosis. These studies have included a small number of subjects and used bone mineral density (BMD) changes rather than fracture occurrence as an endpoint because of the short follow-up. Although the increases in BMD are promising, no intervention is proven to have antifracture efficacy in hepatic osteodystrophy. The natural history of bone disease following liver transplantation has not been fully investigated, although studies suggest that bone mineral loss is transient and generally reverses within a year following transplantation. The approach to treatment in liver transplant recipients should be targeted at preventing the early bone loss without interfering with the later recovery. Based on the available data, no single available agent can be considered as first-line therapy. In our opinion, the best treatment approach involves the elucidation of modifiable risk factors and the selection of agents targeted at the underlying derangements.

Long-term outcome after liver transplantation

Liver transplantation is a life-saving therapy for patients with end-stage liver disease, acute liver failure, and liver tumors. Over the past 4 decades, improvements in surgical techniques, peritransplant intensive care, and immunosuppressive regimens have resulted in significant improvements in short-term survival. Focus has now shifted to addressing long-term complications and improving quality of life in liver recipients. These include adverse effects of immunosuppression; recurrence of the primary liver disease; and management of diabetes, hypertension, dyslipidemia, obesity, metabolic syndrome, cardiovascular disease, renal dysfunction, osteoporosis, and de novo malignancy. Issues such as posttransplant depression, employment, sexual function, fertility, and pregnancy must not be overlooked, as they have a direct impact on the liver recipient's quality of life. This review summarizes the latest data in long-term outcome after liver transplantation.

Osteoporosis is a prevalent finding in patients with solid organ failure awaiting transplantation - a population based study

Post-transplant bone disease is common in solid organ recipients; however, there is limited information on their pre-transplant bone status. We aimed to compare bone mineral density (BMD) in different categories of patients with end-stage organ failure awaiting transplantation (Tx) in Norway. Overall 291 adult patients were enrolled, including 60, 84, 81 and 66 patients with end-stage lung, liver, kidney and heart failure, respectively. Mean age was 51 ± 12 yr with no significant differences between the groups. We measured BMD in lumbar spine, femur, proximal one third and ultra-distal radius by dual energy X-ray absorptiometry. Differences in T- and Z-scores between the groups were compared by ANOVA. Low bone mass was found in all four groups of patients. Both T- and Z-scores differed (p < 0.05) at all measured sites between the groups. Patients with lung failure had the highest prevalence of osteoporosis (67%) and lowest Z-scores, followed by patients with liver (31%), kidney (24%), and heart (23%) failure. Osteoporosis is prevalent in all groups of organ transplant candidates, and poor bone health is remarkably pronounced in patients with chronic lung disease. General practitioners and specialists who care for these patients before they are referred for transplantation should consider measures to prevent osteoporosis at an earlier stage.

Treatment of osteoporosis after liver transplantation with ibandronate

Osteoporosis is a major side-effect after liver transplantation (LTX). Therefore, the objective of the study was to evaluate the efficacy of ibandronate to reduce fractures after LTX. Seventy-four patients after LTX were included in the study and measurements of bone mineral density (BMD) of lumbar spine and proximal femur using dual energy X-ray absorptiometry (DEXA) were performed prior to and 3, 6, 12 and 24 months after surgery. The study group (IBA) consisted of 34 patients who received calcium (1 g/day), vitamin D3 (800-1000 IE/day) and ibandronate 2 mg every 3 months intravenously for 1 year. The control group consisted of 40 patients (CON) who received calcium and vitamin D3 at the same dosages. Prevalence of new fractures was predefined as primary endpoint. Changes of BMD and biochemical markers of bone metabolism were also investigated. In all patients, we found a reduction of BMD in the first few months after LTX. In the lumbar spine and the proximal femur the maximum reduction occurred 3 and 6 months post-LTX. One and 2 years after transplantation, the group receiving ibandronate demonstrated a better recovery from loss of BMD and a significantly lower prevalence of fractures (IBA 2 vs. CON 10 P < 0.04, chi(2)). Ibandronate with calcium and vitamin D3 reduces the BMD-loss after LTX and decreases the rate of bone fractures significantly.

Incidence of abdominal wall numbness post-liver transplantation and its complications

Liver transplantation (LTx) is a life-saving procedure for end-stage liver disease. However, LTx remains a major surgical procedure with a significant amount of morbidity and mortality. Several different types of post-LTx complications have been studied and reported; however, the numbness of the abdominal skin between the subcostal incision and the umbilicus and its associated complications have not been studied in a large patient population. The aim of this study was to report the incidence of numbness in the abdominal skin post-LTx and its implications in routine life. One hundred and one post-LTx patients were questioned in the clinic about numbness. There were 52 male patients and 49 female patients with a mean age of 51.9 +/- 11.3 years at the time of LTx, and the mean time from transplant was 35.0 +/- 29.5 months (range, 3-113 months). The implications were recorded. All 101 patients (100%) had an area of numbness between the subcostal incision and the umbilicus. Four of these patients had an area of superficial-to-deep burns from hot food (accidentally dropped on the abdomen), heating pads, or a hot cup of tea. One patient had ecchymosis from blunt trauma during gardening. Out of 36 diabetic patients, more than 24 patients were insulin-dependent and used the area for subcutaneous insulin injections. In addition, some of the 43 hepatitis C virus-positive patients used the area for subcutaneous interferon therapy. In conclusion, 100% of the patients had persistent numbness up to 9 years following LTx. Five percent of the patients developed thermal injuries or blunt trauma complications that could have been prevented with better education and awareness. More then 24% of the patients used the area for subcutaneous injections of insulin and/or interferon.

Prospective study of bone mineral density and metabolism in patients with chronic hepatitis C during pegylated interferon alpha and ribavirin therapy

The importance of osteoporosis as a complication of end-stage liver disease is well known. However, significant osteopenia may occur in earlier stages of chronic hepatitis C (CHC). Furthermore, antiviral therapy may influence bone metabolism. Thirty patients with CHC genotype 1 infection and without established cirrhosis were treated with peginterferon-alfa and ribavirin. Dual-energy x-ray absorptiometry was performed at baseline, after 48 weeks of therapy, and by the end of a 24-week follow-up period. Bone mineral density (BMD), T-scores, and Z-scores were assessed. Serum C-terminal propeptide of type I collagen (CICP) and osteocalcin levels were measured. Thirteen patients had osteopenia (43%) and osteoporosis was present in four patients (13%). Antiviral therapy led to significant on-treatment increases of lumbar spine and hip BMD (P < or = 0.05) as well as T-scores (P < or = 0.05) and Z-scores (P < or = 0.01) irrespective of subsequent treatment response. Further analyses showed that in patients with sustained virological response (n = 19) most parameters remained highly above baseline values by the end of the 24-week follow-up period, while patients with virological relapse (n = 11) had decreases of BMD, T-scores and Z-scores thereafter that did not differ from baseline. Serum CICP and osteocalcin levels decreased during therapy. Osteocalcin levels remained below baseline in sustained responder, but showed an increase in relapsers by the end of the 24-week follow-up (P < or = 0.05). Osteopenia is detectable in a substantial proportion of CHC patients without established cirrhosis. Antiviral therapy leads to an on-treatment increase of BMD, which may last in those patients who achieve a sustained virological response.

Impaired bone health in adolescents after liver transplantation

Long-term complications related to immunosuppressive medication are an important problem after liver transplantation (OLT). This study was carried out to evaluate the bone health and risk factors for osteoporosis and fractures in 40 pediatric liver transplant recipients. The results of 208 longitudinal bone mineral density (BMD) measurements were analyzed retrospectively. In addition, a dual-energy X-ray absorptiometry was performed to assess the bone mineral content more precisely and to detect subclinical vertebral fractures (VF). The median age of the patients was 14 years and mean postoperative follow-up 7.0 years. The results showed that over half (58%) had lumbar spine (LS) Z-score </=-1.0 and one-fifth (18%) had asymptomatic VF. LS Z-score tended to increase from the first year after OLT, but during puberty the bone mass gain was suboptimal and Z-scores decreased in some subjects. Patients with VF were older at the time of OLT (p = 0.002) and their LS Z-score was lower (p = 0.001). Children transplanted before 10 years of age had less VF (p = 0.004) and higher LS Z-score (p = 0.005) than older patients. In conclusion, adolescent liver recipients are prone to osteoporosis and prevention should be targeted especially to this age group.

Conversion of immunosuppressive monotherapy from cyclosporin a to tacrolimus reverses bone loss in rats

Tacrolimus is used for transplant patients with refractory graft rejection and those with intolerance to cyclosporin (CsA), without the disfiguring adverse effects frequently attributed to CsA therapy. Since we have shown that CsA-associated bone loss can also affect alveolar bone, the purpose of this study was to evaluate the effects of conversion of monotherapy from CsA to tacrolimus on alveolar bone loss in rats. Groups of rats were treated with either CsA (10 mg/kg/day, s.c.), tacrolimus (1 mg/kg/day, s.c.), or drug vehicle for 60 and 120 days, and an additional group received CsA for 60 days followed by conversion to tacrolimus for a further 60-day period. Bone-specific alkaline phosphatase (BALP), tartrate-resistent acid phosphatase (TRAP-5b), calcium (Ca(2+)), interleukin (IL)-1beta, IL-6, and tumor necrosis factor alpha (TNF-alpha) concentrations were evaluated in the serum. Analyses of bone volume, bone surface, number of osteblasts, and osteoclasts were performed. Treatment with CsA for either 60 or 120 days was associated with bone resorption, represented by lower bone volume and increased number of osteoclasts; serum BALP, TRAP-5b, IL-1beta, IL-6, and TNF-alpha were also higher in these animals. After conversion from CsA to tacrolimus, all the altered serum markers returned to control values in addition to a significant increase of bone volume and a lower number of osteoclasts. This study shows that conversion from CsA to tacrolimus therapy leads to a reversal of the CsA-induced bone loss, which can probably be mediated by downregulation of IL-1beta, IL-6, and TNF-alpha production.

Prevention of Early Loss of Bone Mineral Density After Liver Transplantation by Prostaglandin E1

INTRODUCTION

As a result of preexisting chronic liver disease and immunosuppression, the majority of liver transplant patients develop bone mineral density (BMD) loss in the first 3 to 6 months posttransplantation, leading to an increased fracture risk. Using basic prophylaxis and treatment by administration of vitamin D, calcium, and bisphosphonates, BMD loss may be controlled in the long term. In contrast, there is no established medical concept for prevention of early posttransplant BMD loss.

MATERIAL AND METHODS

The aim of this trial was to evaluate the effect of prostaglandin E1 on BMD after liver transplantation. Between 1998 and 2004, 29 patients were enrolled in this study. BMD measurement was performed at lumbar spine and femoral neck using dual energy x-ray absorptometry pretransplant, and 3, 6, 12, and 24 months posttransplant. All patients received calcium and vitamin D as basic prophylaxis. In 13 patients, prostaglandin E1 (PGE) was additionally administered for 12 days posttransplant.

RESULTS

BMD loss was significantly lower at 3 and 6 months posttransplant in the PGE group (lumbar spine, P < .03; femoral neck, P < .009). Development of BMD loss was comparable between both groups during further follow-up. In the PGE group there was a significantly lower fracture rate compared with the controls (P < .02).

CONCLUSION

The application of PGE 1 proved to be beneficial in compensating the early posttransplant BMD loss and in subsequently reducing fracture rate. These positive effects of PGE 1 could be demonstrated in both the femoral neck and lumbar spine.

Bone mineral density before and after OLT: long-term follow-up and predictive factors

Fracturing after liver transplantation (OLT) occurs due to the combination of preexisting low bone mineral density (BMD) and early posttransplant bone loss, the risk factors for which are poorly defined. The prevalence and predictive factors for hepatic osteopenia and osteoporosis, posttransplant bone loss, and subsequent bone gain were studied by the long-term posttransplant follow-up of 360 consecutive adult patients with end-stage primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC). Only 20% of patients with advanced PBC or PSC have normal bone mass. Risk factors for low spinal BMD are low body mass index, older age, postmenopausal status, muscle wasting, high alkaline phosphatase and low serum albumin. A high rate of spinal bone loss occurred in the first 4 posttransplant months (annual rate of 16%) especially in those with younger age, PSC, higher pretransplant bone density, no inflammatory bowel disease, shorter duration of liver disease, current smoking, and ongoing cholestasis at 4 months. Factors favoring spinal bone gain from 4 to 24 months after transplantation were lower baseline and/or 4-month bone density, premenopausal status, lower cumulative glucocorticoids, no ongoing cholestasis, and higher levels of vitamin D and parathyroid hormone. Bone mass therefore improves most in patients with lowest pretransplant BMD who undergo successful transplantation with normal hepatic function and improved gonadal and nutritional status. Patients transplanted most recently have improved bone mass before OLT, and although bone loss still occurs early after OLT, these patients also have a greater recovery in BMD over the years following OLT.

Clinical utility of laboratory testing in women with osteoporosis

Clinicians regularly order laboratory tests in women with osteoporosis to assess if an underlying medical condition is contributing to bone loss. To determine which laboratory tests are associated with osteoporosis we conducted a secondary analyses of data collected as part of the Fracture Intervention Trial (FIT), which included 15,316 postmenopausal women. Women had tests of liver and kidney function, mineral metabolism, electrolytes and complete blood count, femoral neck and total body BMD and spinal radiographs. The prevalence of abnormal tests in women with osteoporosis compared to women without was not different, except for low TSH (<0.5 IU/ml). Among women with and without osteoporosis at the femoral neck the prevalence of low TSH was 4.9% (95% CI: 4.4-5.5) and 3.7% (95% CI: 3.3-4.1), respectively, yielding a positive likelihood ratio of 1.2 (95% CI: 1.1-1.3). We observed similar results for women with vertebral fractures compared to women without vertebral fractures; positive likelihood ratio of 1.4 (95% CI: 1.3-1.6). Our data suggests that when assessing healthy women with osteoporosis ordering a routine panel of laboratory tests is not useful but measuring TSH may be informative.

Cholestatic syndromes

PURPOSE OF REVIEW

This review highlights recent developments in the molecular pathogenesis of cholestasis as well new aspects of pathogenesis and management of clinical cholestatic disorders.

RECENT FINDINGS

Highlights include the role of nuclear receptors including FXR ligands as potential therapeutic agents, new genetic defects for pediatric cholestasis and sclerosing cholangitis, and novel infections and environmental agents as etiologies for primary biliary cirrhosis. Important clinical studies have been published in the area of pediatric cholestatic syndromes, intrahepatic cholestasis of pregnancy, primary biliary cirrhosis, primary and secondary sclerosing cholangitis, cholestasis of sepsis, viral cholestatic syndromes, and drug-induced cholestasis.

SUMMARY

These advances continue to improve understanding of the pathophysiology, diagnosis, and management of cholestatic liver disease.