Potential significance of antiestrogen therapy in the development of bisphosphonate related osteonecrosis of the jaw

Examination of certain single-nucleotide polymorphisms of interleukins 1A and 1B in medication-related osteonecrosis of the jaw - An ambirectional cohort study

AIM

The aim of this study was to examine particular single-nucleotide polymorphisms (IL-1A-889 C/T - rs1800587, IL-1B +3953 C/T - rs 1143634) of interleukins 1A and 1B in the development and prognosis of medication-related osteonecrosis of the jaw.

MATERIALS AND METHODS

DentiGen Parodontitis Tests were applied for collecting samples. This test is suitable for sampling oral mucosa cells in order to detect interleukins 1A and 1B single nucleotide polymorphisms (IL-1A-889, IL-1B+3953). Genetic samples were evaluated in the Istenhegyi Genediagnostic Center using the DNA-hybridization method. Genetic samples were collected in the patient group and the control group. The role of gene polymorphisms in the development of the disease was investigated by comparing the genetic results for the patient and control groups. The investigation of gene polymorphisms in disease prognosis is based on stage improvement, recovery, and relapses following treatment.

RESULTS

In total, 91 patients with MRONJ and 59 healthy controls were included in the study. 51 patients in the patient group and 37 controls had unfavorable allelic variants. No association (Mp = 1.42, SDp = 0.496, Mc = 1.35, SDc = 0.482, p = 0.52) was found between unfavorable polymorphisms and the development of the MRONJ. In the patient group, surgical therapy was required in 79 cases. Stage improvement was detected in 78 cases, recovery in 67 cases, and relapse in 33 cases. No stage improvement was found in one case, recovery in nine cases, or relapse in 34 cases. Of the 79 patients requiring surgical therapy, 49 had unfavorable allelic variants. No connection was found between the polymorphisms examined and stage improvement (Mp = 1.37, SDp = 0.486, Mnp = 2, SDnp = -, p = 0.800) or recovery (Mp = 1.39, SDp = 0.491, Mnp = 1.44, SDnp = 0.527, p = 0.990). However, a significant association (Mp = 1.21, SDp = 0.415, Mnp = 1.58, SDnp = 0.502, p < 0.001) was found between relapses and the presence of unfavorable allelic variants.

CONCLUSION

Within the possible limitations of this study, it can be assumed that the analysis of certain single-nucleotide polymorphisms of interleukin-1 may have the potential to help define the risk stratification of MRONJ after surgical therapy.

Association between Hyperglycemia and Medication-Related Osteonecrosis of the Jaw (MRONJ)

BACKGROUND

Medication-related osteonecrosis of the jaw (MRONJ) is a type of jawbone necrosis caused by the use of drugs for some types of cancer and osteoporosis. The current study aimed to evaluate the associations between hyperglycemia and the development of medication-related osteonecrosis of the jaw.

METHODS

Our research group investigated data collected between 1 January 2019 and 31 December 2020. A total of 260 patients were selected from the Inpatient Care Unit, Department of Oromaxillofacial Surgery and Stomatology, Semmelweis University. Fasting glucose data were used and included in the study.

RESULTS

Approximately 40% of the necrosis group and 21% of the control group presented with hyperglycemia. There was a significant association between hyperglycemia and MRONJ (p < 0.05, p = 0.003). Vascular anomaly and immune dysfunction caused by hyperglycemia can lead to necrosis after tooth extraction. Necrosis is more common in the mandible (75.0%) and in the case of parenteral antiresorptive treatment (intravenous Zoledronate and subcutaneous Denosumab). Hyperglycemia is a more relevant risk factor than bad oral habits (26.7%).

CONCLUSIONS

Ischemia is a complication of abnormal glucose levels, a possible risk factor for necrosis development. Hence, uncontrolled or poorly regulated plasma glucose levels can significantly increase the risk of jawbone necrosis after invasive dental or oral surgical interventions.

The impact of sex steroids on osteonecrosis of the jaw

Sex steroid hormones play a major role in bone homeostasis. Therefore, the use of sex hormones or drugs may increase the risk of osteonecrosis of the jaw (ONJ), a complication caused by damaged bone homeostasis. However, few are known the impact of medications changing sex hormone levels on ONJ. The pathophysiology of ONJ is not clearly understood and many hypotheses exist: cessation of bone remodeling caused by its anti-resorptive effect on osteoclasts; compromised microcirculation due to medication affecting angiogenesis, including bisphosphonate; and impairment of defense mechanism toward local infection. The use of high-dose intravenous bisphosphonate in cancer patients is associated with a high prevalence of ONJ. Exogenous estrogen or androgen replacement was reported to be associated with ONJ. Polycystic ovarian syndrome (PCOS) patients demonstrate an androgen excess status, and androgen overproduction serves as a protective factor in the bone mineral density of young women. To date, there are no reports of ONJ occurrence due to androgen overproduction. In contrast, few reports on the occurrence of ONJ due to estrogen deficiency induced by drugs, such as selective estrogen receptor modulator (SERM), aromatase inhibitors, and gonadotropin-releasing hormone (GnRH) agonists, are available. Thus, the role of sex steroids in the development of ONJ is not known. Further studies are required to demonstrate the exact role of sex steroids in bone homeostasis and ONJ progression. In this review, we will discuss the relationship between medication associated with sex steroids and ONJ.

Moderate-severe grade of chronic graft versus host disease and younger age (less than 45 years old) are risk factors for avascular necrosis in adult patients undergoing allogeneic hematopoietic cell transplantation

Avascular necrosis (AVN) is a debilitating complication of allogeneic hematopoietic cell transplantation (HCT). A retrospective review of 845 patients who underwent HCT was conducted. Cumulative incidence of AVN was 6.3% at 4 years. The following risk factors were significantly associated with AVN risk on univariate analysis: age < 45 (p=0.004), moderate to severe chronic GvHD (p<0.001), reduced intensity conditioning (p=0.02), and a diagnosis of acute leukemia (p=0.045). Multivariate analysis confirmed two risk factors: younger age (<45 years), 9.0% vs 4.4% (p=0.011, hazard ratio (HR) 2.134), and moderate-severe chronic GvHD, 15.4% vs 2.1% (p<0.001, HR 4.950). A risk score model was generated assigning a score to each risk factor. A score of 1 was assigned to moderate-severe GvHD or those with age <45. Total score was calculated, thus dividing patient into three groups: low (score 0, n=349, 41.3%), intermediate (score 1, n=379, 44.9%), and high risk (score 2; n=116, 13.7%). This risk score could stratify the patients according to AVN risk (p<0.001). The risk of AVN was 1.5% in the low risk, 6.2% in the intermediate risk, and 20.8% in the high risk groups. Moderate-severe chronic GvHD and younger age (<45 years) are key risk factors for AVN following allogeneic HCT.

Gingival cell growth with antiresorptive treatment combined with corticosteroids or antiestrogen

Objectives

Antiresorptive treatment has been shown to impair mucosal cell proliferation, migration, and viability. However, in the clinic, antiresorptives are often used in combination with other drugs. We studied the effect of antiresorptives combined with a corticosteroid or antiestrogen on oral mucosal keratinocytes and fibroblasts.

Material and methods

Human gingival keratinocyte and fibroblast cell lines were exposed to bisphosphonates (BPs) and denosumab in different concentrations and durations together with an antiestrogen or corticosteroid. Changes in cell viability, proliferation and migration after exposures were measured. Data were evaluated with hierarchical linear mixed model for repeated measurements.

Results

Bisphosphonate exposure suppressed keratinocyte and fibroblast cell viability, proliferation, and migration in a time‐dependent manner. Combining a corticosteroid or antiestrogen with BPs further increased this negative effect. Denosumab alone had a mild positive effect on keratinocyte and fibroblast growth. When denosumab was combined with a corticosteroid or antiestrogen, cell growth was suppressed.

Conclusions

Our results show that coexisting medications may increase the negative impact of BPs or denosumab on oral mucosal cells.

The effect of melatonin on prevention of bisphosphonate-related osteonecrosis of the jaw: an animal study in rats

Objectives

Melatonin induces human stem cells, converts pre-osteoblasts to mature osteoblasts, and reduces the duration of this transition. However, melatonin itself prevents activation of osteoclasts. Here, we evaluate the role of melatonin in prevention of bisphosphonate-related osteonecrosis of the jaw.

Materials and Methods

In this experimental-interventional study, 30 rats were evaluated in 3 groups. The first and second groups received saline and zoledronic acid, respectively, for 4 weeks and the third group received 4 weeks of zoledronic acid and 3 weeks of melatonin simultaneously. First-right-maxillary-molar extraction was performed for all animals, which were sacrificed after 4 weeks of recovery. The extraction sockets were examined histologically for the presence of osteonecrosis, number of osteoclasts and fibroblasts, severity of inflammation, and vascularization. Data were analyzed by chi-square, one-way ANOVA, Tukey, Kruskal–Wallis and Fisher’s exact statistical tests (α=0.05).

Results

Osteonecrosis was observed in 20%, 90%, and 70% of the first, second and third groups, respectively (P=0.008). The lowest number of osteoclasts and fibroblasts was seen in the third group.

Conclusion

Melatonin may effectively prevent some undesirable side effects of bisphosphonates. However, further studies are required to confirm the results of this study.

Database analysis of the risk factors of bisphosphonate-related osteonecrosis of the jaw in Hungarian patients

OBJECTIVE

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a rare but serious side effect of bisphosphonates (BPs). Since this disease has no independent code in either of the diseases' or in the medical procedures' classifications, it is hard to estimate how many BP patients are affected.

DESIGN

A retrospective observational epidemiological registry-based study was carried out, using the data of the national service of Hungary on the incidence of BRONJ and related factors.

SETTING

A data analysis was performed, which is relevant for the whole Hungarian population from 2010 to 2014. The socioeconomic and medication data of 236 207 BP patients were analysed, and a method was worked out to define BRONJ patients from the Hungarian BP population.

PRIMARY AND SECONDARY OUTCOME MEASURES

The incidences of BRONJ were analysed according to genders and the types of the BP drugs administered. The marginal interdependence between the types of BP drugs, modes of administration and main indication was calculated.

RESULTS

340 BP patients (0.1%) developed BRONJ. The incidence of BRONJ in Hungary in the malignant indication of BPs is 0.9%, and 0.1% in the non-malignant indication, and the OR to develop BRONJ was OR=9.7 (95% CI 7.8 to 12.1) between them. Although more women developed BRONJ, the proportion of men was significantly higher than that of women. Steroids increase the risk of jaw osteonecrosis, and differences were also found between the BP drugs.

CONCLUSIONS

Oncology indicated, intravenously administered and steroid comedicated BP therapies pose a high risk of developing BRONJ in the Hungarian population.

Introducing a protocol to create bisphosphonate-related osteonecrosis of the jaw in rat animal model

OBJECTIVE

Previously published animal investigations on bisphosphonate-related osteonecrosis of the jaws (BRONJ) showed a variety of methods for BRONJ induction and inconsistent findings. The aim of present study was to develop a reliable protocol for BRONJ induction in rat animal model.

SUBJECTS AND METHODS

In a pilot study, 64 rats were randomly divided into 4 groups and 16 subgroups (each containing 2 experimental and 2 control rats) based on the timing of tooth extraction and euthanasia. The experimental and control rats received intraperitoneal injection of 0.06 mg/kg zoledronate and saline, respectively, once a week until sacrificed, and evaluated for presence of bone exposure clinically, and osteonecrosis and new bone formation histologically. The protocol that successfully produced BRONJ in pilot study was tested in a randomized controlled experimental investigation using 45 rats.

RESULTS

In pilot investigation, the highest rate of BRONJ was obtained after four weekly zoledronate injections, at least 4 weeks after tooth extraction. The randomized controlled experimental study verified this finding with a success rate of 83%, and also showed that more prolongation of zoledronate therapy did not increase the BRONJ rate.

CONCLUSION

The protocol developed in the present study could be used reliably for future BRONJ investigations on rats.