C hronic kidney disease (CKD) affects more than 10% of people worldwide. 1 Renal fibrosis is the common endpoint of most CKD. 2 Therefore, preventing or

Protein extravasation and vasodilatation can be induced by neuropeptides released from nociceptive afferents (neurogenic inflammation). We measured electrically evoked neuropeptide release and concomitant protein extravasation in human and rat skin using intradermal microdialysis. Plasmapheresis capillaries were inserted intradermally at a length of 1.5 cm in the volar forearm of human subjects or abdominal skin of rats. Capillaries were perfused with Ringer solution at a flow rate of 2.5 or 1.6 μl min−1. After a baseline period of 60 min capillaries were stimulated electrically (1 Hz, 80 mA, 0.5 ms or 4 Hz, 30 mA, 0.5 ms) for 30 min using a surface electrode directly above the capillaries and a stainless‐steel wire inserted in the capillaries. Total protein concentration was assessed photometrically and calcitonin gene‐related peptide (CGRP) and substance P (SP) concentrations were measured by enzyme‐linked immunosorbent assay (ELISA). In rat skin, electrical stimulation increased CGRP and total protein concentration in the dialysate. SP measurements showed a larger variance but only for the 1 Hz stimulation was the increased release significant. In human skin, electrical stimulation provoked a large flare reaction and at a frequency of 4 Hz both CGRP and SP concentrations increased significantly. In spite of the large flare reactions no protein extravasation was induced, which suggests major species differences. It will be of interest to investigate whether the lack of neurogenic protein extravasation is also valid under pathophysiological conditions.

Autosomal recessive polycystic kidney disease (ARPKD) is a severe pediatric hepatorenal disorder with pronounced phenotypic variability. A substantial number of patients with early diagnosis reaches adulthood and some patients are not diagnosed until adulthood. Yet, clinical knowledge about adult ARPKD patients is scarce. Here, we describe forty-nine patients with longitudinal follow-up into young adulthood that were identified in the international ARPKD cohort study ARegPKD. Forty-five patients were evaluated in a cross-sectional analysis at a mean age of 21.4 (±3.3) years describing hepatorenal findings. Renal function of native kidneys was within CKD stages 1 to 3 in more than 50% of the patients. Symptoms of hepatic involvement were frequently detected. Fourteen (31%) patients had undergone kidney transplantation and six patients (13%) had undergone liver transplantation or combined liver and kidney transplantation prior to the visit revealing a wide variability of clinical courses. Hepatorenal involvement and preceding complications in other organs were also evaluated in a time-to-event analysis. In summary, we characterize the broad clinical spectrum of young adult ARPKD patients. Importantly, many patients have a stable renal and hepatic situation in young adulthood. ARPKD should also be considered as a differential diagnosis in young adults with fibrocystic hepatorenal disease.

No abstract