The Presence of Kidney Cyst Infections in Patients With ADPKD After Kidney Transplantation: Need for Urological Analysis?

To the Editor:

Although disease course is variable in patients with autosomal dominant polycystic kidney disease (ADPKD), the majority of patients need kidney replacement therapy, of which (pre-emptive) kidney transplantation is the modality of first choice. It is assumed that due to their immunocompromised status, transplanted patients with ADPKD are more at risk for the development of kidney cyst infections. However, until recently, no data has been available to support this hypothesis. Recently, KI Reports published a retrospective study of Ronsin et al. that investigated the incidence, risk factors and outcomes of cyst infections in transplanted patients with ADPKD. The authors found that though the incidence of cyst infection after kidney transplantation is low, history of cyst infection before transplantation represents the main risk factor.

This raises the question about whether patients with ADPKD with a history of cyst infections may benefit from pretransplantation nephrectomy. In the study of Ronsin et al., the risk to develop a new cyst infection in a patient with unilateral nephrectomy and a history of cyst infection was 9.1% versus 12.5% in a patient with a positive history for cyst infection, but without preemptive transplantation nephrectomy. This suggests that preemptive nephrectomy may only lead to a relatively small benefit to reduce the chance for a cyst infection. In addition, recurrent cyst infections were only seen in 1 patient after transplantation, indicating that post-transplantation nephrectomy may be an overtreatment in these patients.

It is known that cyst infections often, are caused by an ascending lower urinary tract infection. To exclude other underlying causes of infection, it may be helpful to perform a comprehensive urological analysis, including fluid intake, 24-hour bladder diaries, cystoscopy, uroflowmetry, and post-void residual volume measurement. In recent years, patients who undergo kidney transplantation are older, and it is known that age is positively correlated with the presence of (lower) urinary tract infections. Therefore, a multidisciplinary approach to kidney transplantation in patients with ADPKD may be essential for optimal treatment.