Etiopathogenesis of chronic kidney disease-associated pruritus: putting the pieces of the puzzle together.

Defined as the unpleasant sensation that causes the desire to scratch, pruritus is the most common skin symptom associated with uremia and appears in almost half of patients with advanced chronic kidney disease (CKD). Beyond its direct impact on quality of life, CKD-associated pruritus (CKD-aP) is an independent predictor of mortality that also has a synergistic effect with other quality of life-related symptoms, such as insomnia, depression, and anxiety. Although different mechanisms have been proposed to explain the origin of Pa-ERC, its etiopathogenesis is still not fully understood. Since new therapeutic targets have been identified and several clinical trials have recently shown promising results, our current understanding of the interrelationships has expanded significantly and the pathophysiological mechanisms underlying CKD-aP are now considered to be multifactorial. The potential triggers of pruritus in patients with CKD are discussed in this review, including hypotheses about skin xerosis, accumulation of uremic toxins, dysregulation of the immune system and systemic inflammation, uremic neuropathy, and imbalances in the endogenous opioid system. Other non-uremic causes of pruritus are also discussed, with the aim of guiding the physicians to apply an adequate aetiopathogenic approach to CKD-aP in their day-to-day clinical practice.

Kidney Transplantation Outcomes From Donors After Controlled Circulatory Death: A Comparison With Expanded Criteria Brain Death Donors.

BACKGROUND: The persistent shortage of optimal kidney donors and the progressive increase in patients on the waiting list have led to an expansion of the acceptance criteria, such as donors after controlled cardiac death (cDCD) and donors after brain death with expanded criteria (DBD-EC). Some concerns and doubts about survival outcomes achieved with these allografts are still present. Our aim was to compare transplant outcomes from cDCD vs DBD-EC. METHODS: A retrospective single-center observational study including all kidney transplant (KT) donors from all cDCD and DBD-EC (>60 years) from January 2015 to January 2022 was performed. We analyzed clinical characteristics, early clinical outcomes, and patient and graft survival rates. RESULTS: 129 cDCD and 166 DBD-EC KT recipients were included. The median follow-up was 30,2 months. DBD-EC were older and had more comorbidities than cDCD. KTs from cDCD and DBD-EC showed similar rates of delayed graft function and primary nonfunction. Patient survival at 1 year was similar (85% DBD-EC vs 90% cDCD, P = .32). Death-censored graft survival at 1 year was similar among young cDCD (18-59 years) and elderly DBD (60-69 years; 97% vs 92.3%, P = .2). Recipient age and expanded criteria in KT from cDCD were related to worse early graft outcomes. The outcomes achieved with KT from cDCD were similar to those observed in older and more comorbid DBD donors. This assumption is worth consideration when choosing the most suitable donor for each recipient.

Expanding Criteria in Controlled Cardiac Death Donors: Now With 70-Year-Old Donors.

BACKGROUND: Outcomes of kidney transplant (KT) after controlled cardiac death with older donors are under review. We aimed to analyze early and midterm clinical outcomes using older (≥70 years) controlled cardiac death donors (cDCD). METHODS: Retrospective observational single-center study including all KTs from donors ≥70 years from cDCD and donors after brain death (DBD) performed from January 2017 to January 2022. We performed a comparative study between the 2 groups (cDCD and DBD). An analysis of clinical characteristics, early clinical outcomes, and patient and graft survival rates was made. RESULTS: We included 25 cDCD KTs and 63 DBD KTs ≥70 years. The median follow-up was 18.7 months. Recipients from cDCD were more comorbid. Donors from DBD showed higher hypertension and stroke rate. The KTs from older cDCD showed similar delayed graft function rate (cDCD: 34.6% vs DBD extended criteria donor: 35.3%, P = .59) and primary nonfunction (cDCD 16% vs DBD 17.4%, P = .85) compared with older DBD. Medium (3 years) graft death-censored survival was satisfying (cDCD 73% vs DBD 72%) despite a relevant early graft failure rate in both groups (cDCD 16% vs DBD 23%, P = .26). No differences were observed in patient survival at year 1 (cDCD 94% vs DBD 93%, P = .62). CONCLUSIONS: In our series, the outcomes with older cDCD are similar compared with older DBD. Although older donors showed an increase of early graft failure, these kidneys allowed us to maximize the opportunities for candidates that otherwise should remain on dialysis.