From the Guidelines
Advanced age is a significant risk factor for developing pyelonephritis due to decreased immune function, anatomical and functional changes in the urinary tract, and increased comorbidities. Elderly individuals experience a decline in immune function, making them less able to fight off urinary tract infections before they ascend to the kidneys 1. Age-related anatomical and functional changes in the urinary tract also contribute, including incomplete bladder emptying, increased post-void residual urine, and prostatic hypertrophy in men. Older adults often have more comorbidities like diabetes and neurological conditions that impair bladder function. Additionally, the prevalence of urinary catheterization increases with age, creating direct pathways for bacteria to enter the urinary system.
Some key factors that increase the risk of pyelonephritis in older adults include:
- Decreased immune function
- Anatomical and functional changes in the urinary tract
- Increased comorbidities, such as diabetes and neurological conditions
- Increased prevalence of urinary catheterization
- Atypical symptoms, leading to delayed diagnosis and treatment
- Hormonal changes in older women, including decreased estrogen, which alter the vaginal flora and reduce natural defenses against uropathogens.
When treating pyelonephritis in elderly patients, clinicians must consider age-appropriate antibiotic dosing, potential drug interactions with multiple medications, and increased risk of adverse effects due to reduced renal function, as highlighted in a recent study 1. This study emphasizes the importance of taking into account potential drug interactions and contraindications, such as impaired kidney function, when selecting treatment for older individuals. Therefore, a comprehensive approach to managing pyelonephritis in older adults is crucial to optimize outcomes and reduce the risk of morbidity and mortality.
From the Research
Risk Factors for Pyelonephritis
Advanced age is considered a risk factor for developing pyelonephritis due to several factors, including:
- Weakened immune system: As people age, their immune system becomes less effective at fighting off infections, making them more susceptible to developing pyelonephritis 2.
- Increased prevalence of underlying medical conditions: Older adults are more likely to have underlying medical conditions, such as diabetes, that can increase their risk of developing pyelonephritis 3.
- Decreased renal function: Advanced age can lead to decreased renal function, making it more difficult for the kidneys to filter out bacteria and other toxins, increasing the risk of developing pyelonephritis 2.
Pathogenesis of Pyelonephritis
The pathogenesis of pyelonephritis involves the infection of the kidney and renal pelvis by bacteria, typically Escherichia coli. The infection can cause inflammation and damage to the kidney tissue, leading to symptoms such as flank pain and laboratory evidence of urinary tract infection 4.
- The innate immune system plays a crucial role in protecting the urothelium from bacterial challenge, with antimicrobial peptides demonstrating potent bactericidal activity toward uropathogens 5.
- The adaptive immune system, including cellular immunity, also plays a role in the pathogenesis of pyelonephritis, with changes in the level of pro- and anti-inflammatory cytokines contributing to the development of the infection 6.
Clinical Outcomes and Risk Factors for Mortality
Advanced age is associated with an increased risk of mortality from pyelonephritis, with other risk factors including: