Osteomalacia induced by long-term low-dose adefovir dipivoxil: Clinical characteristics and genetic predictors

Follow-Up of Adefovir Dipivoxil Induced Osteomalacia: Clinical Characteristics and Genetic Predictors

Adefovir dipivoxil (ADV) is widely used for chronic hepatitis B therapy in China. To explore the clinical features and prognosis of ADV-induced osteomalacia and to analyze the association between osteomalacia and genetic variants in 51 drug transporters genes. Clinical and follow-up data of the ADV-treated patients were collected. Target capture sequencing was used to identify genetic variations of 51 drug transporter genes. A total of 193 hepatitis B patients treated with ADV were enrolled, of whom 140 had osteomalacia. The other 53 without osteomalacia were included in the control group. The median duration of ADV treatment before the onset of osteomalacia was 6.5 years (range:1.5–7 years). We found that most patients with osteomalacia had hypophosphatemia, high serum alkaline phosphatase levels, hypouricemia, nondiabetic glycosuria, proteinuria. Stopping ADV administration, supplementing calcitriol and calcium were effective treatments. During 3–6 months of follow-up, the clinical symptoms and biochemical indicators of patients with osteomalacia have been significantly improved. There was no significant difference in duration of adefovir treatment in patients with or without osteomalacia (p = 0.791). Through regression analysis, we found that age was a risk factor for osteomalacia [per 1 year, odds ratio (OR), 1.053; 95% confidence interval (95% CI), 1.020–1.087; p = 0.015]. 1992 single nucleotide variants were found using target capture sequencing. However, the associations of genetic variants of 51 drug transporter genes and the risk of osteomalacia were negligible. Osteomalacia is prone to occur in patients with chronic hepatitis B treated with long-term ADV at a therapeutic dose. After standard treatment, the prognosis is mostly good. We failed to find genetic variants that can predict the risk of ADV-induced osteomalacia.

Cross-sectional retrospective analysis of clinical characteristics of chronic hepatitis B patients with oral antiviral treatment in eastern China

BACKGROUND

In China, more than 20 million patients with chronic hepatitis B need antiviral treatment. Side effects of antiviral treatment such as renal complications can be problematic, particularly in an aging population.

METHODS

The data were retrospectively extracted from the hospital medical charts of five centers in eastern China from January 1 to December 31, 2018.

RESULTS

A total of 8309 patients with CHB was enrolled in this study. The median age of the patients was 46 years. The prevalence of diabetes mellitus, hypertension, and hepatic cirrhosis was respectively 3.49%, 4.42%, and 23.72%. The prevalence of these comorbidities increased with age (P < 0.001). Of the patients with CHB, 5332 had complete renal function results. Among them, patients with an estimated glomerular filtration rate of < 60 mL/min/1.73m² accounted for 4.14%, and those with proteinuria for 8.33%. According to the definition of chronic kidney disease, the proportion of patients with chronic kidney disease was 11.37%. The prevalence of chronic kidney disease increased with age (P < 0.001). In a multivariate analysis, age group [odds ratio (OR) = 2.387], diabetes mellitus (OR = 1.486), hypertension (OR = 2.557), hepatic cirrhosis (OR = 1.295), and a history of exposure to adefovir dipivoxil (OR = 1.644) were significantly associated with CKD (P < 0.05). Among patients with CKD, 17.66% (107/606) had a history of lamivudine exposure, and 34.65% (210/606) had a history of nucleotide analogue exposure CONCLUSION: The management of Chinese patients with CHB should take into consideration age, previous medication history, and renal impairment.

Retrospective analysis of the clinical characteristics of adefovir dipivoxil-induced Fanconi's syndrome in the Chinese population

WHAT IS KNOWN AND OBJECTIVE

To explore the clinical characteristics of adefovir dipivoxil-induced Fanconi's syndrome in the Chinese population and provide a reference for rational drug use in the clinic.

METHODS

By searching the CNKI, Wanfang, Chinese VIP, PubMed/MEDLINE, Web of Knowledge, Ovid, Elsevier and SpringerLink databases during 1 January 2008 to 31 December 2019, 78 studies of ADV-induced Fanconi's syndrome involving a total of 110 patients were collected and analysed retrospectively.

RESULTS AND DISCUSSION

Prolonged usage of adefovir dipivoxil at low doses to treat hepatitis B might cause Fanconi's syndrome as the first symptom, especially for use over 12 months.The main clinical manifestation was bone pain accompanied by hypophosphataemia, elevated alkaline phosphatase (ALP), urine glycosuria and urine protein. X-rays and bone mineral density (BMD) examinations were mainly used to characterized osteoporosis. The patients had pain relief within 1 week to 1 month, and the biochemical indicators returned to normal within from 2 to 4 months.

WHAT IS NEW AND CONCLUSION

Sufficient attention is required before and during exposure to long-term ADV therapy. The clinical picture, laboratory and radiograph alterations are important clues for ADV-induced Fanconi's syndrome.

Low-dose adefovir dipivoxil-induced hypophosphatemia osteomalacia in five chronic hepatitis B virus-infected patients. Is low-dose adefovir dipivoxil-induced nephrotoxicity completely reversible?

Adefovir dipivoxil (ADV) is one of the most important nucleostide analogues currently in use for the treatment of chronic hepatitis B virus (HBV) infection. Low-dose ADV-induced nephrotoxicity in most cases was reported to be reversible after the discontinuation of ADV or by decreasing the dose of ADV. In our study, we have 5 documented cases of low-dose ADV-induced hypophosphatemia osteomalacia with or without Fanconi syndrome which were diagnosed in our hospital between 2010 and 2017. Three patients were observed to have a full recovery after the discontinuation of ADV. Two patients had persistently elevated urine β₂-microglobulin levels and out of these two patients, one patient had persistent hypophosphatemia after the cessation of ADV. These cases illustrated that the use of low-dose ADV increased the risk of nephrotoxicity, and in some patients, low-dose ADV-induced nephrotoxicity was not completely reversible. Patients of East Asian origin, especially those with a low body mass index, were prone to a relatively higher risk of developing low-dose ADV-induced nephrotoxicity; therefore, it was worth paying attention to the side effects caused by low-dose ADV.

Adefovir dipivoxil induced hypophosphatemic osteomalacia in chronic hepatitis B: a comparative study of Chinese and foreign case series

BACKGROUND

Adefovir dipivoxil (ADV)-induced renal tubular dysfunction and hypophosphatemic osteomalacia (HO) have been given great consideration in the past few years. However, no standard guidance is available due to a lack of powerful evidence from appropriate long-term prospective case-control studies and variations in the definition of renal adverse events. The aim of this study is to clarify clinical features of ADV-related HO in Chinese chronic hepatitis B patients with long-term ADV treatment in Chinese and non-Chinese comparative case series.

METHODS

Retrieval of case reports was based on Pubmed, CNKI, Wan Fang and VIP databases using the key words adefovir dipivoxil, hypophosphatemia, osteomalacia and Fanconi syndrome. We divided patients into Chinese (C group) and Foreign (F group) groups according to their nationality. Comparisons involving demographics, clinical manifestations, tests, treatment and prognosis were conducted between the two groups.

RESULTS

Of the patients screened, 120 Chinese patients were identified in the C group, and 32 non-Chinese patients were identified in the F group. The average age of the C group was younger than that of the F group (51.89 years ±10.96 years versus 56.47 years ±11.36 years, t = - 2.084, P = 0.039). No significant difference was found in gender (male to female, 3.29:1 versus 3:1, χ ²  = 0.039, P = 0.844). Although there was no significant difference in the duration of ADV therapy before ostalgia onset, the C group tended to develop adverse events earlier, by 2-3 years, while the F group developed adverse events at 4-5 years (Z = - 1.517, P = 0.129). Prognosis was good after adjustment of the ADV dose and supplemental administration of phosphate and calcitriol. Time to resolution of tubular dysfunction was commenced at the first month, and Chinese patients were more prone to recover in the first 3 months than non-Chinese patients (91.3% of patients in the C group versus 56.3% in the F group, Z = - 3.013, P = 0.003).

CONCLUSIONS

Sufficient attention is required for middle-aged males before and during exposure to long-term ADV therapy, regardless of nationality. The clinical picture, laboratory and radiograph alterations are important clues for those patients and are usually characterized by polyarthralgia, renal tubular dysfunction and mineralization defects. Implementation of an early renal tubular injury index is recommended for patients with higher risk, which would prevent further renal injury.

Adefovir-Induced Hypophosphatemic Osteomalacia Mimicking Bone Metastases From Primary Hepatocarcinoma

Adefovir-induced hypophosphatemic osteomalacia in the context of hepatocarcinoma is rare and needs to be differentiated from metastatic hepatocarcinoma. We here report a case of severe osteomalacia whose focal uptakes of radiotracer on the Tc-MDP SPECT/CT images mimicked that of metastatic hepatocarcinoma.

Clinical features of hypophosphatemic osteomalacia induced by long-term low-dose adefovir dipivoxil

Objective

To investigate the predictors of hypophosphatemic osteomalacia induced by adefovir dipivoxil (ADV) and to monitor for early detection.

Patients and methods

Hospitalized patients who were diagnosed with ADV-related hypo-phosphatemic osteomalacia were recruited and retrospectively analyzed in our hospital from January 2012 to December 2016. A telephone interview was conducted at 1, 3, 6, 9, 12, and 24 months after cessation of ADV.

Results

In the 8 patients enrolled in the study, the hypophosphatemic osteomalacia symptoms developed at an average of 5.14 (4–7) years since ADV treatment (10 mg/d). The average alkaline phosphatase (ALP) level was 279.50 (137–548) U/L, which was significantly higher than the normal level (45–125 U/L). The serum phosphorus level was an average of 0.59 (0.43–0.69) mmol/L, which was lower than the normal range (2.06–2.60 mmol/L). Serum calcium levels of the enrolled patients remained within normal limits. Reduced estimated glomerular filtration rate (eGFR <29 mL/min/1.73 m²) was seen in 4 cases. The clinical manifestations were mainly progressive systemic bone and joint pain, frequent fractures, trouble in walking, height reduction (4–6 cm), and so on. After cessation of ADV, symptoms like bone pain resolved gradually. Serum phosphorus level restored to normal in 4.5 months after the withdrawal of ADV. However, in 4 patients, renal function failed to return to normal in 24 months.

Conclusion

More attention should be paid to the duration of ADV treatment. The level of serum phosphorus and ALP, as well as renal function, should be monitored for early detection of potential adverse drug reactions.