Circulating FGF-23 was significantly elevated in patients with CKD and its concentration correlated with renal creatinine clearance. In healthy volunteers, FGF-23 levels did not change after phosphate deprivation or phosphate loading.

An increased incidence of osteoporotic fractures after renal transplantation was found in diabetic and female patients. The mechanism behind bone fragility in IDDM is multifactorial and despite a restored renal function bone disease may progress, and is probably enhanced by the immunosuppressive treatment.

In the past years dialyzers have been improved, and consequently pyrogenic reactions have become rare. However, some patients in our dialysis unit have shown symptoms during hemodialysis which we suspected could be caused by endotoxins. These patients, as well as controls without similar symptoms, had elevated levels of circulating endotoxin. We therefore measured endotoxin in blood from patients with chronic renal failure and different kinds of treatment. Serum samples were analyzed with a sensitive method described in the literature, using a chromogenic substrate and Limulus amebocyte lysate. In patients on hemodialysis (mean ± SEM) the endotoxin value in samples taken immediately before dialysis was 40 ± 4.7 ng/l and significantly elevated (p < 0.001) compared with the endotoxin value (7 ± 0.6 ng/l) found in the healthy reference group. Increased endotoxin levels were also seen in patients on hemofiltration (19 ± 7.5 ng/l) and in patients with conservative treatment and various degrees of renal insufficiency (17 ± 2.5 ng/l). Patients on peritoneal dialysis and renal-transplanted patients had levels not different from the controls. The mechanism behind endotoxemia in uremia is unknown but may partly be explained by reduced endotoxin elimination due to impaired liver macrophage function. The differences in endotoxin levels in patients on peritoneal or hemodialysis treatment may reflect that extracorporeal circulation enhances endotoxin entrance to the circulation and/or that endotoxin clearance is dependent on the dialysis regimen.

No abstract

Hyaluronate, a glycosaminoglycan of connective tissue matrix, was measured in serum by radioassay in patients with renal insufficiency (n = 22) and with end-stage renal failure (n = 40). The serum hyaluronate levels were significantly increased in both groups compared with the levels measured in age- and sex-matched healthy controls. Significant correlations were found between serum hyaluronate and degree of impaired renal function. None of the patients had laboratory signs indicating affection of the liver, the major elimination route for circulating hyaluronate. No significant alteration of hyaluronate levels was seen during hemodialysis. Renal transplants, previously on dialysis treatment, had normal serum hyaluronate values. Data obtained indicate either an essential role of the kidneys for the elimination of circulating hyaluronate or an increased outflow of hyaluronate to the circulation in uremia or a combination of these two possibilities. The altered metabolism of hyaluronate in uremia was not only related to the azothemic state but also to the age of the patients. The mechanism may be qualitively similar to that underlying the age-dependent increase of serum hyaluronate seen in health. The hypothesis that elevated serum hyaluronate in uremia may reflect an accelerated ageing of the connective tissue is highly speculative, but has some support by the finding that cardiovascular and other clinical symptoms were linked to particularly high serum levels of hyaluronate.