Indoleamine 2,3-Dioxygenase Is Involved in Interferon Gamma's Anti-BKPyV Activity in Renal Cells

Intravesical Interferon Therapy vs Hyaluronic Acid for Pain Among Female Individuals With Interstitial Cystitis: A Randomized Clinical Trial

Importance

Interstitial cystitis (IC) is a debilitating condition. Although viral infection is a potential etiological cause, few studies have detected the effect of antiviral treatment.

Objective

To determine the efficacy and safety of intravesical interferon instillation compared with hyaluronic acid in female patients with IC.

Design, Setting, and Participants

This double-masked, randomized phase 2/3 clinical trial with parallel group design was implemented from October 2022 to April 2023 and had a 6-month follow-up period. The study was conducted at a single center. Eligible participants were female patients aged 18 to 70 years with a diagnosis of IC for more than 6 months. The last visit took place in October 2023. Data were analyzed between October and November 2023.

Intervention

Patients were randomized 1:1 to receive either intravesical instillation of interferon or hyaluronic acid.

Main Outcomes and Measures

The primary end point was change in visual analog scale pain score. Secondary end points included changes in voiding frequency, functional bladder capacity, symptom index, and global response assessment. Adverse events were closely monitored.

Results

Among the 52 patients, the mean (SD) age was 50.0 (14.1) years and they were randomized to either the interferon group (26 [50%]) or hyaluronic acid (26 [50%]). The visual analog pain score showed the interferon group decreased more significantly than hyaluronic acid (-1.3; 95% CI, -2.3 to -0.3; P = .02) at month 6, with 20 patients (77%) exhibiting a 30% or higher reduction in pain compared with baseline. Secondary end points of voiding frequency, functional bladder capacity, and nocturia episodes showed no significant difference between 2 therapies. However, interferon showed a significantly higher reduction in the Interstitial Cystitis Symptom Index (-3.0; 95% CI, -5.3 to -0.7; P = .01) and the Problem Index (-2.5; 95% CI, -4.5 to -0.4; P = .02) at month 6, with 22 patients (85%) presenting as moderately or markedly improved. The frequencies of adverse events were similar between 2 groups. Only 1 patient discontinued hyaluronic acid because of poor effectiveness.

Conclusions and Relevance

In this randomized clinical trial, female patients with IC could benefit from intravesical interferon therapy, without serious adverse events. These results offered hope for antiviral approaches in IC, but larger-scale, multicenter trials and long-term follow-up should be considered.

Trial Registration

ClinicalTrials.gov Identifier: NCT05912946.

BK Polyomavirus bkv-miR-B1-5p: A Stable Micro-RNA to Monitor Active Viral Replication after Kidney Transplantation

Background: Bkv-miR-B1-5p is a viral micro-RNA (miRNA) specifically produced during BK polyomavirus (BKPyV) replication. Recent studies have suggested using bkv-miR-B1-5p as a biomarker to monitor viral infection and predict complications in kidney transplant patients. To identify the technical limitations of this miRNA quantification in biological samples, knowledge of its stability and distribution in the extracellular compartment is necessary. Moreover, a proof of concept for using bkv-miR-B1-5p as a biomarker of active replication in chronic infection is still missing in the published literature. Methods: The stability of bkv-miR-B1-5p was evaluated in samples derived from cell cultures and in urine from BKPyV-infected kidney transplant recipients. The miRNA was quantified in different fractions of the extracellular compartment, including exosomes, and protein binding was evaluated. Finally, we developed an in vitro model for chronic culture of BKPyV clinical isolates to observe changes in the bkv-miR-B1-5p level during persistent infections. Results: Bkv-miR-B1-5p is a stable biomarker in samples from humans and in vitro experiments. Marginally associated with the exosomes, most of the circulating bkv-miR-B1-5p is bound to proteins, especially Ago2, so the miRNA quantification does not require specific exosome isolation. The bkv-miR-B1-5p level is predictable of viral infectivity, which makes it a potential specific biomarker of active BKPyV replication after kidney transplantation.

BK Virus and Transplantation

As guest editors, we are pleased to present this Special Issue on BK virus (BKV) and transplantation with the intention of exploring some aspects related to BKV-associated diseases in transplant recipients, since they are still unclear [...].