Foscarnet-induced crystalline glomerulonephritis with nephrotic syndrome and acute renal failure after kidney transplantation

Long-term use of foscarnet is associated with an increased incidence of acute kidney injury in hematopoietic stem cell transplant patients: A retrospective observational study

BACKGROUND

Foscarnet is an important drug for the treatment of cytomegalovirus infection in patients undergoing hematopoietic stem cell transplantation (HSCT). Foscarnet is often discontinued because of the development of acute kidney injury (AKI). Thus, the identification of factors leading to the development of AKI is beneficial. This study aimed to investigate the incidence of AKI and the factors influencing AKI development in HSCT patients treated with foscarnet.

METHODS

This was a retrospective observational study. Patients who underwent HSCT and received foscarnet at the Department of Hematology, Osaka City University Hospital, were identified from medical records. The patients were classified into AKI and non-AKI groups, and the risk factors associated with AKI were evaluated. For continuous variables, receiver-operating characteristic (ROC) curve analysis was used to calculate the optimal cutoff value.

RESULTS

Thirty-five patients (47 cases) were assigned to the AKI (51.1%, 24/47) and non-AKI groups (48.9%, 23/47). The AKI group had a significantly longer foscarnet administration period than the non-AKI group (p = 0.049). The appropriate cutoff value for the foscarnet administration period using ROC curve was 27 days. The incidence of AKI was significantly higher in cases who received foscarnet for more than 27 days (11/14, 78.6%) compared to those who received less than 27 days (13/33, 39.4%) (odds ratio: 5.64, 95% confidence interval 1.32-24.2, p = 0.024).

CONCLUSION

The incidence of AKI was 51.1% in HSCT patients treated with foscarnet, and foscarnet administration for more than 27 days may be associated with the incidence of AKI. This article is protected by copyright. All rights reserved.

Safety considerations with current and emerging antiviral therapies for cytomegalovirus infection in transplantation

Introduction: Human cytomegalovirus (HCMV) is a major contributor of morbidity and mortality, and its management is essential for the successful outcome of solid organ and hematopoietic stem cell transplantation. Areas covered: This review discusses the safety profiles of currently available and emerging antiviral drugs and the other strategies for HCMV prevention and treatment after transplantation. Expert opinion: Strategies for management of HCMV rely largely on the use of antiviral agents that inhibit viral DNA polymerase (ganciclovir/valganciclovir, foscarnet, and cidofovir/brincidofovir) and viral terminase complex (letermovir), with different types and degrees of adverse effects. An investigational agent, maribavir, exerts its anti-CMV effect through UL97 inhibition, and its safety profile is under clinical evaluation. In choosing the antiviral medication to use, it is important to consider these safety profiles in addition to overall efficacy. In addition to antiviral drugs, reduction of immunosuppression is often generally needed in the management of HCMV infection, but with a potential risk of allograft rejection or graft-versus-host disease. The use of HCMV-specific or non-specific intravenous immunoglobulins remains debated, while adoptive HCMV-specific T cell therapy remains investigational, and associated with unique set of adverse effects.

Safety and efficacy of foscarnet for the management of ganciclovir-resistant or refractory cytomegalovirus infections: A single-center study

BACKGROUND

Infection with cytomegalovirus (CMV) is an important cause of morbidity and mortality following solid organ transplantation. Resistance to ganciclovir can rarely develop via mutations in UL97 or UL54. There are limited published studies assessing the safety and efficacy of foscarnet for the management of ganciclovir-resistant or refractory cytomegalovirus infection and many centers are reluctant to utilize this important therapy because of concerns about toxicity.

METHODS

Solid organ recipients transplanted between January 1, 2006 and December 31, 2014 who received at least 1 dose of foscarnet were retrospectively reviewed to assess treatment outcomes, tolerability, and safety of foscarnet.

RESULTS

Ten of 31 (32.3%) patients who received foscarnet during the study period died during treatment with foscarnet, whereas all 21 surviving recipients successfully cleared infection. Of these surviving patients, 3 (14.3%) developed significant renal dysfunction, defined as >25% decline in estimated glomerular filtration rate during treatment; one-third had definitive renal biopsy results consistent with foscarnet-induced toxicity.

CONCLUSION

Although mortality was high in this population, foscarnet use, with proper precautions, was generally safe and significant renal dysfunction was lower than previously reported in other sources, even with extended use.

Brincidofovir Use after Foscarnet Crystal Nephropathy in a Kidney Transplant Recipient with Multiresistant Cytomegalovirus Infection

Background. Cytomegalovirus (CMV) antiviral drug resistance constitutes an increasing challenge in transplantation. Foscarnet is usually proposed when resistance for ganciclovir is suspected, but its use is limited by its nephrotoxicity. Case Presentation. We report a case of multiresistant CMV disease in a kidney transplant recipient. Foscarnet was prescribed after ganciclovir treatment failure in a patient with two mutations in the UL97 viral gene. Foscarnet induced biopsy-proven kidney crystal precipitation that resulted in severe acute transplant failure and nephrotic syndrome. Despite a large decrease in immunosuppression, CMV disease was not controlled and a salvage therapy with Brincidofovir (BCV), which is an oral lipid conjugate of cidofovir with limited nephrotoxicity, was attempted. Clinical and virological remission was observed after a 21-day course of BCV, despite mild and reversible liver toxicity. However, a new relapse could not be effectively cured by BCV due to a new mutation in the UL54 gene, which is known to confer resistance to cidofovir. A new course of foscarnet finally resulted in prolonged CMV remission. Herein, we present a review of foscarnet nephropathy cases in solid-organ transplanted patients. Conclusions. This unique case highlights the potential benefit of BCV use during resistant CMV infection, although mutations in the UL54 gene may limit its therapeutic efficacy. These findings need to be confirmed in clinical trials.

Umbilical Cord Blood Transplantation-associated Nephrotic Syndrome Successfully Treated by Low-density Lipoprotein Apheresis

The development of nephrotic syndrome (NS) after umbilical cord transplantation (UBT) has been reported in only four cases to date. We herein report the case of a 50-year-old woman who developed NS 94 days after UBT. She fell into oliguria and required dialysis. A kidney biopsy revealed focal and segmental glomerulosclerosis. Although glucocorticoid monotherapy did not improve her condition, the addition of low-density lipoprotein (LDL) apheresis resulted in remission of NS, a drastic improvement in her renal function, and withdrawal from dialysis. To the best of our knowledge, this is the first report of UBT-associated NS treated with LDL apheresis.

Gold standards in pharmacovigilance: the use of definitive anecdotal reports of adverse drug reactions as pure gold and high-grade ore

Anecdotal reports of adverse drug reactions are generally regarded as being of poor evidential quality. This is especially relevant for postmarketing drug safety surveillance, which relies heavily on spontaneous anecdotal reports. The numerous limitations of spontaneous reports cannot be overemphasised, but there is another side to the story: these datasets also contain anecdotal reports that can be considered to describe definitive adverse reactions, without the need for further formal verification. We have previously defined four categories of such adverse reactions: (i) extracellular or intracellular tissue deposition of the drug or a metabolite; (ii) a specific anatomical location or pattern of injury; (iii) physiological dysfunction or direct tissue damage demonstrable by physicochemical testing; and (iv) infection, as a result of the administration of an infective agent as the therapeutic substance or because of demonstrable contamination. In this article, we discuss the implications of these definitive ('between-the-eyes') adverse effects for pharmacovigilance.

Inhibition of HSV-1 replication and HSV DNA polymerase by the chloroxoquinolinic ribonucleoside 6-chloro-1,4-dihydro-4-oxo-1-(beta-D-ribofuranosyl) quinoline-3-carboxylic acid and its aglycone

We describe in this paper that the synthetic chloroxoquinolinic ribonucleoside 6-chloro-1,4-dihydro-4-oxo-1-(beta-D-ribofuranosyl) quinoline-3-carboxylic acid (compound A) and its free aglycogene base (compound B) inhibit, with low cytotoxicity, the replication of herpes simplex virus type 1 and 2 (HSV-1 and HSV-2). Compound A inhibited HSV-1 replication in Vero cells with an EC(50) of 1.3 and 1.4 microM for an acyclovir (ACV)-sensitive strain and an ACV-resistant strain of this virus, respectively. Additionally, it inhibited HSV-2 replication with an EC(50) of 1.1 microM. Compound B also inhibited the ACV-sensitive and -resistant HSV-1 strains, and HSV-2 at EC(50) values of 1.7, 1.9 and 1.6 microM, respectively. Time-of-addition assays, performed with compound A, suggested that this molecule at an early time point of the HSV replication cycle. Kinetic assays demonstrated that compounds A and B inhibit the HSV DNA polymerase activity in a noncompetitive fashion, with a K(i) equal to 0.1 and 0.2 microM, respectively. Taken together, our results suggest that compounds A and B represent promising lead molecules for further anti-HSV drug design.

Viral and fungal infections after liver transplantation--part II

Viral and fungal infections in liver transplant recipients are important to recognize and treat early because of their association with substantial morbidity and mortality. Some viruses, such as cytomegalovirus and human herpesvirus 6, have immunomodulatory properties and can facilitate other infections, including fungal infections. Cytomegalovirus has long been recognized as an important virus in transplantation, but in the past decade other viruses have also received attention in the medical literature because of their association with particular clinical syndromes. Although human herpesvirus 6 has been associated with fever, rash, and encephalitis, a direct cause-and-effect relationship is still lacking. Human herpesvirus 8 has been found to be the cause of Kaposi sarcoma. Molecular techniques (e.g., pp65 antigenemia and polymerase chain reaction) that have been introduced for routine diagnosis of viruses have facilitated the diagnosis of asymptomatic viral infections and the institution of preemptive therapy. Nonetheless, the diagnosis of invasive fungal infections in liver transplant recipients is often delayed and thus associated with high mortality. Despite the use of new antifungal agents in clinical practice and the reduced incidence of fungal infections because of antifungal prophylaxis regimens, mortality has not decreased. Future patient outcomes may improve with early identification of patients who have risk factors for invasive fungal infections and with the development of new molecular diagnostic techniques for early detection.

Post-transplant nephrotic syndrome: A comprehensive clinicopathologic study

BACKGROUND

Post-transplant (Tx) nephrotic syndrome (NS) is not well defined.

METHODS

Seventy-four renal transplant recipients with NS were studied.

RESULTS

Biopsies showed chronic allograft nephropathy (CAN) in 31 patients; recurrent glomerular disease (GN) in 15, de novo GN in 18, and undetermined GN in 9. NS developed 0.25 to 384 months post-Tx and was treated with angiotensin-converting enzyme inhibitors (ACEI) or angiotensin receptor blockers (ARB) in 18 patients; calcium channel blockers in 25; or both drugs in 31. NS remitted in 24% of cases 2 to 28 months after onset, and this persisted in all except 3 patients. The remission rate was lowest (9%) for CAN and highest (47%) for de novo GN. Compared with persistent NS, those with remission showed higher prevalence of de novo GN (53% vs. 17%), lower prevalence of CAN (18% vs. 50%), earlier onset of NS (39 vs. 59 months), lower serum SCr at onset (2.3 vs. 2.9 mg/dL), and higher incidence of treatment with ACE or ARB. The 5-year graft loss rates for CAN, recurrent and de novo GN were 57%, 36%, and 23%, respectively. Compared with the functioning grafts, the failed grafts showed higher prevalence of CAN (60% vs. 16%), lower prevalence of de novo GN (12% vs. 46%), earlier onset of NS (47 vs 65 months post-Tx), higher serum SCr at onset (3.3 vs. 2.0 mg/dL), lower prevalence of remission of NS (5% vs. 48%), and higher proteinuria at follow-up (5.1 vs. 2.5 g/day). Graft survival improved with NS remission (88% vs. 18%).

CONCLUSION

Post-Tx NS displays distinctive clinicopathologic features with pathogenetic and therapeutic implications.

The remission of post-transplant nephrotic syndrome clinicopathologic characterization

Among 67 renal transplant recipients with nephrotic syndrome (NS), nine episodes were reversible in eight patients. Biopsies showed minimal-change disease, focal segmental membranous glomerulonephritis and acute glomerulitis, IgA nephropathy and acute glomerulitis or thrombotic microangiopathy, and chronic transplant nephropathy with or without acute glomerulitis. NS developed 1-4 months post transplant in the four patients with minimal-change disease, but later (33-151 months) in the others. At onset, serum creatinine was normal or elevated. Treatment included calcium-channel blockers, angiotensin-converting enzyme inhibitors, or both, together with routine antirejection therapy. Remission was achieved 4-12 months after onset, when renal function remained normal in four, improved in four, and worsened in one. At last follow-up, six patients still had remission and functional grafts. One lost graft to chronic transplant nephropathy while NS remained in remission. In the remaining patient, proteinuria, which was due to chronic transplant glomerulopathy unrelated to the initial minimal-change disease-associated NS, recurred 50 months post transplant. Remission of post-transplant NS is possible. It is often associated with minimal-change diseases and less frequently with other glomerular lesions, including acute glomerulitis. Reversible post-transplant NS does not have an adverse effect on the renal allografts.

Infections in recipients of kidney transplants

A review of infections in kidney transplant recipients is presented in this article, beginning with a discussion of the pretransplant infectious diseases evaluation and an overview of the timing of infectious posttransplant, and then focusing on individual types of infection.

Irreversible glomerular lesions induced by crystal precipitation in a renal transplant after foscarnet therapy for cytomegalovirus infection

AIMS

Foscarnet is an antiviral agent used to treat cytomegalovirus infection in AIDS patients and in transplant recipients. In most cases, foscarnet induces reversible tubulo-interstitial lesions which can be avoided by correct hydration. We report the first case of crystal foscarnet precipitation within glomerular capillaries in a renal transplant.

METHODS AND RESULTS

The recipient, a 49-year-old man, developed a nephrotic syndrome with haematuria and an acute renal failure after foscarnet therapy for cytomegalovirus (CMV) infection. The polarization examination of the first graft biopsy revealed the presence of birefringent crystals within glomeruli and tubules. Infrared analysis attested to the presence of trisodium foscarnet salts and mixed sodium calcium salts coloured by Von Kossa's reaction. A second biopsy showed glomerular sclerosis, interstitial fibrosis, tubular atrophy and crystal vanishing. Polymerase chain reaction (PCR) in situ applied to this biopsy confirmed the diagnosis of cytomegalovirus infection.

CONCLUSIONS

These adverse effects might be the result of a toxic synergy between foscarnet and other drugs. In cases with crystalline precipitation, graft biopsy remains the best mean of diagnosis and follow-up of glomerular damage.