Nephrolithiasis and Osteomalacia associated with adefovir-induced Fanconi syndrome in a patient with hepatitis B

Successful Resolution of Suspected Red Yeast Rice-induced Nephropathy

Recently, several Japanese patients have developed interstitial nephritis or acute tubular injury/necrosis, both accompanied by Fanconi syndrome, after consuming a specific red yeast rice supplement. In most cases, the renal function did not fully recover even after discontinuation of supplements and glucocorticoid treatment. A 52-year-old woman developed interstitial nephritis and Fanconi syndrome after receiving supplements. A renal biopsy revealed mild lymphocytic infiltration. Her renal function recovered after discontinuing the supplement without glucocorticoids. The supplement was contaminated with puberulic acid, a known cause of tubular necrosis; however, the cause of interstitial nephritis remains uncertain. Biopsy findings guided the decision to avoid glucocorticoids.

Osteomalacia and renal failure due to Fanconi syndrome caused by long-term low-dose Adefovir Dipivoxil: a case report

Background

Progressive bone pain and fracture and abnormal positron emission tomography combined with a computed tomography are main reasons for the oncologists suspecting bone tumor. During the patient’s medical treatment, the oncologists’ unfamiliarity with adverse reactions to anti-HBV drugs were main reason for the long-term exposure to the drug and the adverse reaction (ADR) experienced by the patient.

Case presentation

A 63-year-old Chinese man had a 27-month history of progressive generalized bone pain combined with spontaneous fractures. Positron emission tomography combined with a computed tomography, revealed an abnormal increase in ribose metabolism and low positron serum inorganic phosphorus concentration (0.7; 0.78–1.65 mmol/L). Serum creatinine level was 252 μmol/L (53–97) μmol/L, and glomerular filtration rate was 22.79 mL/min/1.73 m². The patient was referred to a multidisciplinary clinic to clarify the diagnosis of myeloma or bone tumor for further treatment in 2017. His medical history revealed that he had a 30-year history of chronic hepatitis B infection. He had received lamivudine at a daily dose of 100 mg for 19 years (1990 to 2009), which had been changed to adefovir (10 mg/day) owing to lamivudine resistance in 2009. Based on the changes in the patient’s laboratory markers and the results of emission computed tomography and other radiographic findings, adefovir-induced hypophosphatemic osteomalacia due to acquired renal Fanconi syndrome was suspected by the clinical pharmacist. Considerable clinical improvement was observed after adefovir discontinuation and the administration of entecavir (1.0 mg, every other day).

Conclusion

Fanconi syndrome with osteomalacia can develop in patients with chronic hepatitis B infection being treated with adefovir at a conventional low dosage of 10 mg/day. This case highlights the importance of ADR as a differential diagnosis and the need of pharmacists with drug safety expertise expert in the patient management.

Hypophosphatemic Osteomalacia Associated with Adefovir-induced Fanconi Syndrome Initially Diagnosed as Diabetic Kidney Disease and Vitamin D Deficiency

A 68-year-old man with type 2 diabetes mellitus and chronic hepatitis B infection was referred to the nephrology department before planned surgery for hepatocellular carcinoma. He had been receiving low-dose adefovir dipivoxil (ADV) for 11 years. Laboratory findings revealed impaired re-absorption in the proximal renal tubules. He had been diagnosed with diabetic kidney disease and osteomalacia due to vitamin D deficiency; thus, ADV was not discontinued until he was referred to us. In this case, concomitant diabetes mellitus and vitamin D deficiency might have prevented the early diagnosis of ADV-induced Fanconi syndrome.

Tenofovir disoproxil fumarate/emtricitabine is associated with a higher risk of hypocalcemia compared to abacavir/lamivudine - results from a German cohort study

Hyperparathyroidism has been described in people living with HIV undergoing tenofovir disoproxil fumarate (TDF)-containing antiretroviral therapy (ART), but differences in calcium levels have never been investigated in detail. We aimed to compare the prevalence of hypocalcemia between patients with and without TDF-containing ART. The patients and methods were a retrospective cohort study in HIV-infected adult patients receiving dolutegravir and either abacavir (ABC)/lamivudine (3TC) or TDF/emtricitabine in a single center in Munich, Germany. Of 172 patients, 126 (73.3%) were male and the median age was 48.5 years (interquartile range 42-54). Average calcium levels were 2.24 (2.21-2.29) mmol/l and 2.21 (2.16-2.26) mmol/l (P < 0.001) with a prevalence of at least one episode of total calcium <2.12 mmol/l of 16.2 and 34.4% in the groups treated with ABC/3TC and TDF/emtricitabine, respectively (P = 0.006). TDF use was independently associated with the occurrence of albumin-corrected calcium levels of <2.12 mmol/l (odds ratio: 6.7 [1.3-35.6]; P = 0.025). Hypocalcemia seems to occur more often in TDF-treated patients. Further research into hypocalcemia with TDF and potential cardiovascular effects may be of benefit based on these findings.

Legionella Pneumonia Complicated with Acquired Fanconi Syndrome

Legionella pneumonia is occasionally accompanied by renal complications; however, the cause of this remains unknown. We herein report a 70-year-old Japanese man with Legionella pneumonia who presented with hyponatremia, hypophosphatemia, and hypouricemia. The levels of urinary β2-microglobulin and N-acetyl-β-D-glucosaminidase were remarkably high, indicating severe renal tubular damage. The presence of glycosuria and aminoaciduria as well as increased fractional excretion of uric acid and decreased tubular reabsorption of phosphate indicated that the patient's condition was complicated with Fanconi syndrome. After antimicrobial therapy, the electrolyte abnormalities and renal tubular damage were completely resolved.