Collapsing focal segmental glomerulosclerosis following long-term treatment with oral ibandronate: case report and review of literature

Podocyte Disease Following Treatment with Intravenous Ibandronate in an Older Patient

Bisphosphonates are commonly used to treat osteoporosis. While renal toxicity is common with pamidronate and zoledronate, few ibandronate-related cases are reported. We describe a rare case of ibandronate-associated nephrotoxicity. An 88-year-old woman was admitted for edema. She had been receiving intravenous ibandronate treatment for postmenopausal osteoporosis and had no other diagnosed diseases. She was presented with proteinuria, hypoalbuminemia (1.9 g/dL), and an elevated serum creatinine level (1.8 mg/dL). Renal biopsy revealed podocyte disease, favoring a diagnosis of focal segmental glomerulosclerosis. She was treated with diuretics, tacrolimus, and fimasartan. Steroids were avoided due to severe osteoporosis. Three months later, the edema had subsided and the laboratory findings had improved (serum albumin 3.5 g/dL, serum creatinine 0.97 mg/dL). This case emphasizes the importance of careful monitoring of proteinuria and renal function during ibandronate treatment. In older adult patients, kidney biopsy and immunosuppressive treatment may be considered based on physical activity and underlying diseases.

Nephrotic syndrome with acute kidney injury due to focal segmental glomerulosclerosis following long-term treatment with minodronate

Although bisphosphonates are well known to cause kidney disease, there are very few published cases of focal segmental glomerulosclerosis (FSGS) following treatment with minodronate. Here we report the case of an 86-year-old woman who developed acute kidney injury and nephrotic syndrome after receiving monthly oral minodronate for 24 months. Kidney biopsy revealed cellular variant FSGS. Treatment was initiated with the discontinuation of minodronate followed by intravenous methylprednisolone pulse and prednisolone at 35 mg/day. Subsequently, the patient's renal function gradually worsened, requiring initiation of hemodialysis. However, renal function and proteinuria improved markedly and hemodialysis was withdrawn 1 month after the initiation of steroid therapy. This is, to our knowledge, the first published case of FSGS induced by long-term use of minodronate, and also the first case of cellular variant FSGS induced by bisphosphonates although collapsing variant of FSGS is commonly caused by bisphosphonates. Our study indicates that patients on bisphosphonates should be closely monitored for proteinuria and renal impairment, regardless of the type of bisphosphonate.

Autoimmunity in Focal Segmental Glomerulosclerosis: A Long-Standing Yet Elusive Association

Focal segmental glomerulosclerosis (FSGS) is a histological term that describes a pathologic renal entity affecting both adults and children, with a wide array of possible underlying etiologies. Podocyte damage with scarring, the hallmark of this condition, leads to altered permeability of the glomerular barrier, which may result in massive proteinuria and relentless renal function deterioration. A definite cause of focal segmental glomerulosclerosis can be confirmed in a minority of cases, while most forms have been traditionally labeled as primary or idiopathic. Despite this definition, increasing evidence indicates that primary forms are a heterogenous group rather than a single disease entity: several circulating factors that may affect glomerular permeability have been proposed as potential culprits, and both humoral and cellular immunity have been implicated in the pathogenesis of the disease. Consistently, immunosuppressive drugs are considered as the cornerstone of treatment for primary focal segmental glomerulosclerosis, but response to these agents and long-term outcomes are highly variable. In this review we provide a summary of historical and recent advances on the pathogenesis of primary focal segmental glomerulosclerosis, focusing on implications for its differential diagnosis and treatment.

Drug-induced nephrotoxicity

Acute kidney injury is a very common diagnosis, present in up to 60% of critical patients, and its third main cause is drug toxicity. Nephrotoxicity can be defined as any renal injury caused directly or indirectly by medications, with acute renal failure, tubulopathies, and glomerulopathies as common clinical presentations. Some examples of drugs commonly associated with the acute reduction of glomerular filtration rate are anti-inflammatories, antibiotics, such as vancomycin and aminoglycosides, and chemotherapeutic agents, such as cisplatin and methotrexate. Cases of tubulopathy are very common with amphotericin B, polymyxins, and tenofovir, and cases of glomerulopathies are common with VEGF inhibitors, bisphosphonates, and immunotherapy, and it is also common to have more than one clinical presentation related to a single agent. Early diagnosis is essential for the good evolution of the patient, with a reduction of renal exposure to the toxic agent, which requires knowing the risk factors and biomarkers. General measures such as correcting hydroelectrolytic disorders and hypovolemia, monitoring the serum level, avoiding combinations with the synergy of renal injury, and looking for similar options that are less toxic are the foundations for the treatment of complications that are still common and often preventable.

Nephrotoxicity of anticancer treatment

Severe adverse systemic drug events occur commonly as a result of treatment of cancer patients. Nephrotoxicity of chemotherapeutic agents remains a significant complication limiting the efficacy of the treatment. A variety of renal disease and electrolyte disorders can result from the drugs that are used to treat malignant disease. The kidneys are a major elimination pathway for many antineoplastic drugs and their metabolites. Tumour lysis syndrome, an emergency in haematooncology, occurs most often after the initiation of cytotoxic therapy in patients with high-grade lymphomas and acute lymphoblastic leukaemia. Chemotherapeutic agents can affect the glomerulus, tubules, interstitium and renal microvasculature, with clinical manifestations that range from asymptomatic elevation of serum creatinine to acute renal failure requiring dialysis. Some factors such as intravascular volume depletion, as well as concomitant use of other drugs or radiographic ionic contrast media, can potentiate or contribute to the nephrotoxicity. Cytotoxic agents can cause nephrotoxicity by a variety of mechanisms. The most nephrotoxic chemotherapeutic drug is cisplatin, which is often associated with acute kidney injury. Many other drugs such as alkylating agents, antimetabolites, vascular endothelial growth factor pathway inhibitors and epidermal growth factor receptor pathway inhibitors may have toxic effects on the kidneys. The aim of this review is to discuss the issue of nephrotoxicity associated with chemotherapy. In routine clinical practice, monitoring of kidney function is mandatory in order to identify nephrotoxicity early, allowing dosage adjustments or withdrawal of the offending drug.

Cancer and the kidney: dangereoux liasons or price paid for the progress in medicine?

A long time ago, the links between renal disease and malignancy were observed, however, quite recently, their importance was recognized and 'new' subspecialty in nephrology, namely 'onconephrology' was established. In the XXI century, patients with malignancy make up the most growing number of the subjects seen for nephrology consult and/or critical care nephrology services. A plethora of renal problems may be found in patients with malignancy. They may influence not only their short-term outcomes but also the adequate therapy of the underlying oncological problem. Thus, all these kidney-related issues pose an important challenge for both specialities: oncology and nephrology. In the review a spectrum of acute and chronic renal injury caused by the malignancy is presented as well as the associations between renal disease and cancer. Assessment of kidney function and its importance in patients with malignancy is also discussed as medical oncologists should check the appropriate dose of chemotherapeutic drugs in relation to the actual renal function before prescribing them to the patients. Moreover, effects of kidney function on outcomes in oncology is presented. In addition, nephrology services should better understand both the biology of malignancy with its treatment to become a valuable part treating team to yield the best possible outcome. It is important for nephrology services to be acknowledged and to take an active participation in care of oncology patients.

Collapsing glomerulopathy, the Saudi Arabian scenario. A study of 31 cases and a review of literature

Objectives:

To compare the clinico-pathological features of collapsing glomerulopathy (CG) at a tertiary hospital in Saudi Arabia with the world literature.

Methods:

In a retrospective study, all biopsy-diagnosed cases of CG between 2004-2015 were identified and analyzed, at King Khalid University Hospital, King Saud University, Riyadh. The clinico-pathological findings along with prognosis were reviewed and compared with the reported literature.

Results:

Thirty-one CG patients were identified, most were adult males. All the CG cases were idiopathic, all Arabs, none HIV positive, none of African descent, and none with a history of drug abuse. The number of glomeruli with collapsing lesions per biopsy ranged from 1 to 9. Other types of FSGS lesions (not otherwise specified and perihilar) were also noted. There was extensive podocyte effacement. Upon treatment, remission (complete/partial) was noted in almost half the patients; around one fourth did not respond to treatment; and one fourth progressed to end stage kidney disease (ESKD). The median time taken to develop ESKD from the time of biopsy diagnosis was 23 months.

Conclusion:

The clinico-pathological and prognostic correlates of CG in Saudi Arabia are comparable with that of the world literature. The management protocol at our center is the same as that practiced in different parts of the world, and the prognosis is overall poor.