The homozygous G>A transition that results in the substitution of histidine for arginine at position 495 of the renal sodium-dependent phosphate transporter, SLC34A1, is involved in disease pathogenesis in these patients. Our report of the second family with two mutated SLC34A1 alleles expands the known phenotype of this rare condition.

We evaluated the relationship between the acute phase and the development of end-stage renal disease (ESRD) and the outcome of renal transplant in patients with Shiga toxin-associated hemolytic uremic syndrome (Stx-HUS). A 20-year retrospective study was performed of 66 renal transplants in 62 patients with Stx-HUS compared with 189 renal allografts in 178 children with other diseases. Of 62 patients, 61 had >7 days of oliguria during the acute phase. Stx-HUS patient survival was not different from controls (92% vs. 83% 15 years after renal transplantation). In the cyclosporine (CsA) era, survival of grafts from living related (LRD) and cadaver (CD) donors in Stx-HUS and control patients was 83% versus 70% ( P<0.03) and 77% versus 49% ( P<0.05) at 10 years. Graft survival in Stx-HUS and dysplasia/obstructive uropathy patients was 79% versus 76% ( P=NS), but it was different from that of other diseases (79% vs. 58%, P<0.001). There was no clinical or histopathological evidence of Stx-HUS recurrence. In conclusion, in Stx-HUS patients the duration of the acute oliguric period was a good predictor for the progression to ESRD. Use of CsA and the absence of recurrence of the disease influenced the excellent prognosis in Stx-HUS patients after renal transplantation. The development of ESRD in Stx-HUS could be mediated by non-immunological factors.

No abstract

Monocytes (Mo) mediate central functions in inflammation and immunity. Different subpopulations of Mo with distinct phenotype and functional properties have been described. Here, we investigate the phenotype and function of peripheral Mo from children with hemolytic uremic syndrome (HUS). For this purpose, blood samples from patients in the acute period of HUS (HUS AP) were obtained on admission before dialysis and/or transfusion. The Mo phenotypic characterization was performed on whole blood by flow cytometry, and markers associated to biological functions were selected: CD14 accounting for lipopolysaccharide (LPS) responsiveness, CD11b for adhesion, Fc receptor for immunoglobulin G type I (FcgammaRI)/CD64 for phagocytosis and cytotoxicity, and human leukocyte antigen (HLA)-DR for antigen presentation. Some of these functions were also determined. Moreover, the percentage of CD14+ CD16+ Mo was evaluated. We found that the entire HUS AP Mo population exhibited reduced CD14, CD64, and CD11b expression and decreased LPS-induced tumor necrosis factor production and Fcgamma-dependent cytotoxicity. HUS AP showed an increased percentage of CD14+ CD16+ Mo with higher CD16 and lower CD14 levels compared with the same subset from healthy children. Moreover, the CD14++ CD16- Mo subpopulation of HUS AP had a decreased HLA-DR expression, which correlated with severity. In conclusion, the Mo population from HUS AP patients presents phenotypic and functional alterations. The contribution to the pathogenesis and the possible scenarios that led to these changes are discussed.

MMF has been shown to decrease the incidence of acute rejection in children and adults at 1 and 3 yr. Other beneficial effects of MMF have been more difficult to demonstrate. Our open‐labeled study presents a 5‐yr data for patients and graft survival, allograft function, and growth in MMF‐treated patients. The trial included 29 patients who were treated with MMF in combination with cyclosporine and methylprednisone. Patients were compared with a preceding group of 29 patients treated with AZA instead of MMF. Patient and graft survival rate 5 yr after transplantation were 97 and 90% in the MMF group vs. 93 and 83% in the AZA group (p: NS). Acute rejection was 20.6% in the MMF group vs. 58.6% in the AZA group (p < 0.01). Chronic rejection was 10.3% in the MMF group and 25% in the AZA group (p: NS). The changes in the creatinine clearance from baseline to 5 yr (Δ) were different between groups (−6.0 ± 5.1 mL/min/1.73 m2 in the MMF group vs. −22.2 ± 7.6 mL/min/1.73 m2 in the AZA group, p < 0.05). Also, the slope of 1/Scr showed a significant lower incidence of worsening renal function after the second year of renal transplantation (p < 0.0001) in the MMF group compared with the AZA group. Δ Height SDS in prepubertal patients was 0.3 ± 0.4 SDS in the MMF group vs. −0.8 ± 0.2 SDS in the AZA group (p < 0.05). This study shows that long‐term MMF therapy has resulted in a decrease in acute rejection and was associated with a protection against renal function deterioration. The use of MMF enables a reduction in the dose of steroids and leads to a linear growth improvement of children after renal transplantation.