From the Guidelines
The chance of developing a fungal infection in the kidney is relatively low, but it can occur, particularly in individuals with compromised immune systems, with Candida species being the most common cause, as noted in the 2016 update by the Infectious Diseases Society of America 1.
Key Factors Influencing Risk
- Individuals with compromised immune systems, such as those with diabetes, undergoing immunosuppressive therapy, organ transplant recipients, patients with HIV/AIDS, and those with indwelling urinary catheters, are at a higher risk of developing kidney fungal infections.
- The risk of fungal infection in the kidney is estimated to be less than 1% of all kidney infections in healthy individuals, but this risk increases significantly in immunocompromised patients.
Diagnosis and Treatment
- Diagnostic tests on urine often are not helpful in differentiating colonization from infection, and imaging of the urinary tract by ultrasound or CT scanning is helpful in defining structural abnormalities and fungus ball formation 1.
- Fluconazole is the drug of choice for treating Candida UTI, as it achieves high concentrations in the urine and is effective in eradicating candiduria, as shown in a randomized, double-blind, placebo-controlled trial 1.
- Treatment typically involves antifungal medications such as fluconazole (200-400mg daily for 2-6 weeks), amphotericin B (0.5-1.0 mg/kg/day), or echinocandins like caspofungin (70mg loading dose, then 50mg daily) depending on the specific fungus identified.
Prevention
- Maintaining good blood sugar control for diabetics, appropriate management of immunosuppressive medications, and proper catheter care can help reduce the risk of these infections.
- Fungal infections target the kidneys because these organs filter blood and can trap fungal elements, while providing a nutrient-rich environment for fungal growth when normal defenses are compromised.
From the Research
Fungal Infection in Kidney
- The chance of fungal infection in the kidney is a significant concern, particularly in immunocompromised patients and those with renal dysfunction 2.
- Invasive fungal infections can lead to immense morbidity and mortality in patients with renal diseases, and management strategies often have a narrow safety profile and involve high costs 2.
- The use of intravenous liposomal amphotericin B appears to be an effective alternative to conventional amphotericin B for the treatment of invasive fungal infections in patients with renal dysfunction, due to its improved tolerability profile 2.
Risk Factors and Diagnosis
- Patients with renal dysfunction, such as acute renal failure, chronic kidney disease, dialysis dependency, or renal transplant recipients, are at higher risk of developing invasive fungal infections 2.
- Renal zygomycosis, caused by invasive fungi, can present as acute renal failure, and a high index of suspicion and timely diagnosis are crucial for proper management 3.
- Definitive diagnosis of fungal infection in the kidney can only be made by kidney biopsy, as radiological investigations can only provide clues 3.
Treatment Options
- Various antifungal agents are available for the treatment of invasive fungal infections, including lipid formulations of amphotericin B, voriconazole, caspofungin, and micafungin 4, 5.
- Voriconazole is a new second-generation triazole effective against a wide spectrum of fungal pathogens and has a good safety profile, with limited evidence of azole cross-resistance of clinical importance 6.
- The choice of antifungal agent depends on the characteristics of the agent, including spectrum, pharmacokinetic profile, route of administration, efficacy in clinical trials, safety profile, drug-drug interactions, and cost 5.