To investigate whether the derangements in calcium kinetics in patients with renal osteodystrophy are similar in the various histologic forms of this metabolic bone disease, 43 patients on chronic maintenance dialysis underwent calcium kinetic studies using the double isotope technique, iliac crest bone biopsies for mineralized bone histology and histomorphometry and determinations of serum indices of calcium and bone metabolism. Intestinal calcium absorption was not different among the three histologic groups. However, women exhibited lower calcium absorption in each histologic form (P < 0.01). Patients with predominant hyperparathyroid bone disease showed plasma calcium efflux, calcium accretion rate and calcium retention markedly above normal values. Patients with low turnover bone disease exhibited a normal or slightly decreased plasma calcium efflux and calcium accretion rate together with a disproportionately low calcium retention. Patients with mixed uremic osteodystrophy presented with a calcium kinetic profile intermediary to the two other forms. Good relationships existed between plasma calcium efflux, calcium accretion rate, calcium retention and histomorphometric parameters of bone turnover as well as serum levels of parathyroid hormone. However, no serum parameter could indicate with certainty the underlying bone disease. These findings demonstrate that adynamic bone disease does not merely represent an academic finding but is characterized by a very low bone capacity to buffer calcium and inability to handle an extra calcium load. This is particularly relevant for the daily care of end-stage renal failure patients presently receiving higher than ever amounts of vitamin D and calcium salts.

Cellular immune responses in vitro were studied in 24 patients on chronic hemodialysis and 16 healthy volunteers with normal kidney function. Patients on maintenance hemodialysis had lymphopenia with diminished numbers of both T4+ and T8+ T-lymphocytes. The T4/T8 ratios were within the normal range. Peripheral blood lymphocytes (PBL) showed a diminished proliferative response upon stimulation with concanavalin A, phytohemagglutinin and pokeweed mitogen. When cell surface antigens were used for stimulation (mixed lymphocyte culture) uremic lymphocytes also showed a lower proliferation rate. Although without statistical conformation, there was a tendency by uremic PBL to produce less IL-2 as compared to healthy controls. Moreover, in a PWM driven system, peripheral blood lymphocytes from uremics produced significantly less IgG than PBL from normals. These results support the notion that a profound defect in lymphocyte function accounts at least, in part, for the observed immunodeficiency of uremic patients.

In 2009, a multinational group of clinicians was charged with reviewing and evaluating the research base pertaining to incontinence-associated dermatitis (IAD) and synthesizing this knowledge into best practice recommendations based on existing evidence. This is the first of 2 articles focusing on IAD; it updates current research and identifies persistent gaps in our knowledge. Our literature review revealed a small but growing body of evidence that provides additional insight into the epidemiology, etiology, and pathophysiology of IAD when compared to the review generated by the first IAD consensus group convened 5 years earlier. We identified research supporting the use of a defined skin care regimen based on principles of gentle perineal cleansing, moisturization, and application of a skin protectant. Clinical experience also supports application of an antifungal powder, ointment, or cream in patients with evidence of cutaneous candidiasis, aggressive containment of urinary or fecal incontinence, and highly selective use of a mild topical anti-inflammatory product in selected cases. The panel concluded that research remains limited and additional studies are urgently needed to enhance our understanding of IAD and to establish evidence-based protocols for its prevention and treatment.