Bisphosphonate therapy after liver transplant improves bone mineral density and reduces fracture rates: an updated systematic review and meta-analysis

Bone pattern changes in post liver transplant patients using bisphosphonates

OBJECTIVE

To identify radiographic findings suggestive of drug-induced osteonecrosis and evaluate radiomorphometric patterns indicative of changes in bone mineral density in individuals transplanted for liver disorders using bisphosphonates.

STUDY DESIGN

The study group included panoramic x-rays of liver transplant patients who are being monitored and who present a clinical status of osteoporosis and use bisphosphonates. The control group was made up of liver transplant patients who did not have osteoporosis. On panoramic radiographs, mental index (MI) and mandibular cortical index (MCI) and the presence of radiographic anomalies suggestive of osteonecrosis were evaluated.

RESULTS

There were significant statistical results when comparing the groups in relation to the decrease in bone mineral density (BMD) with MCI-C3 (p = 0.036), however, there were none in relation to MI (p = 0.14). There were no valid statistical results when relating MCI (p = 0.94) and MI (p = 0.66) with reduced BMD and use of bisphosphonates.

CONCLUSION

Liver transplant individuals using bisphosphonates present greater radiographic signs of bone sclerosis suggestive of a greater propensity to develop osteonecrosis of the jaw and an increased risk of presenting changes suggestive of reduced bone mineral density on panoramic radiographs when compared to liver transplant individuals not using bisphosphonates.

Alagille syndrome: understanding the genotype-phenotype relationship and its potential therapeutic impact

INTRODUCTION

Alagille syndrome (ALGS) is an autosomal dominant, multisystem genetic disorder with wide phenotypic variability caused by mutations in the Notch signaling pathway, specifically from mutations in either the Jagged1 (JAG1) or NOTCH2 gene. The range of clinical features in ALGS can involve various organ systems including the liver, heart, eyes, skeleton, kidney, and vasculature. Despite the genetic mutations being well-defined, there is variable expressivity and individuals with the same mutation may have different clinical phenotypes.

AREAS COVERED

While no clear genotype-phenotype correlation has been identified in ALGS, this review will summarize what is currently known about the genotype-phenotype relationship and how this relationship influences the treatment of the multisystemic disorder. This review includes discussion of numerous studies which have focused on describing the genotype-phenotype relationship of different organ systems in ALGS as well as relevant basic science and population studies of ALGS. A thorough literature search was completed via the PubMed and National Library of Medicine GeneReviews databases including dates from 1969, when ALGS was first identified, to February 2023.

EXPERT OPINION

The genetics of ALGS are well defined; however, ongoing investigation to identify genotype-phenotype relationships as well as genetic modifiers as potential therapeutic targets is needed. Clinicians and patients alike would benefit from identification of a correlation to aid in diagnostic evaluation and management.

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.

Evaluation of Bone Mineral Metabolism After Liver Transplantation by Bone Mineral Densitometry and Biochemical Markers

AIM

This study aimed to evaluate the course of bone and mineral metabolism after liver transplantation (LT) in patients with chronic liver disease.

METHODS

One hundred four patients who had undergone LT and had a minimum of 6 months of follow-up after LT were included in this prospective cohort study. The following parameters were evaluated for each patient: preoperative and postoperative (postoperative day [POD]30, POD90, POD180) osteocalcin, bone-specific alkaline phosphatase (BALP), type 1 collagen, beta-C-terminal end telopeptide (β-CTx), vitamin D, parathyroid hormone (PTH), ALP, calcium, phosphate, sedimentation, and bone mineral densitometer scores (L2, L4, L total, and F total). The parameters were compared in terms of sex, presence of liver tumor (hepatocellular carcinoma [HCC; n = 19] vs non-HCC [n = 85]), and presence of autoimmune liver disease (autoimmune liver disease [ALD; n = 8] vs non-ALD [n = 96]).

RESULTS

The median age of the patients (n = 81 men and n = 23 women) was 52 years (95% CI, 50-56). There was a significant change in the defined time intervals in parameters such as osteocalcin (P < .001), BALP (P < .001), β-CTx (P < .001), vitamin D (P < .001), PTH (P < .001), ALP (P = .001), calcium (P < .001), phosphate (P = .001), L2 (P = .038), L total (P = .026), and F total (P < .001) scores. There was a significant difference in POD90 ALP (P = .033), POD180 calcium (P = .011), POD180 phosphate (P = .011), preoperative sedimentation (P = .032), and POD180 F total (P = .013) scores between both sexes. There was a significant difference in POD180 osteocalcin (P = .023), POD180 β-CTx (P = .017), and preOP calcium (P = .003) among the HCC and non-HCC groups. Furthermore, we found significant differences in preoperative ALP (P = .008), preoperative sedimentation (P = .019), POD90 (P = .037) and POD180 L2 (P = .005) scores, preoperative (P = .049) and POD180 L4 (P = .017), and POD180 L total (P = .010) and F total (P = .022) scores between the patients with and without ALD.

CONCLUSION

This study shows that the bone and mineral metabolism of the LT recipients was negatively affected after LT. In addition, we showed that bone and mineral metabolism was more prominent in patients with HCC, and bone mineral density scores were higher in patients with ALD.

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.

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.