Divergent Effects of Glucocorticoids on Cortical and Trabecular Compartment BMD in Childhood Nephrotic Syndrome

Glucocorticoid (GC) effects on skeletal development have not been established. The objective of this pQCT study was to assess volumetric BMD (vBMD) and cortical dimensions in childhood steroid‐sensitive nephrotic syndrome (SSNS), a disorder with minimal independent deleterious skeletal effects. Tibia pQCT was used to assess trabecular and cortical vBMD, cortical dimensions, and muscle area in 55 SSNS (age, 5–19 yr) and >650 control participants. Race‐, sex‐, and age‐, or tibia length‐specific Z‐scores were generated for pQCT outcomes. Bone biomarkers included bone‐specific alkaline phosphatase and urinary deoxypyridinoline. SSNS participants had lower height Z‐scores (p < 0.0001) compared with controls. In SSNS, Z‐scores for cortical area were greater (+0.37; 95% CI = 0.09, 0.66; p = 0.01), for cortical vBMD were greater (+1.17; 95% CI = 0.89, 1.45; p < 0.0001), and for trabecular vBMD were lower (?0.60; 95% CI, = ?0.89, ?0.31; p < 0.0001) compared with controls. Muscle area (+0.34; 95% CI = 0.08, 0.61; p = 0.01) and fat area (+0.56; 95% CI = 0.27, 0.84; p < 0.001) Z‐scores were greater in SSNS, and adjustment for muscle area eliminated the greater cortical area in SSNS. Bone formation and resorption biomarkers were significantly and inversely associated with cortical vBMD in SSNS and controls and were significantly lower in the 34 SSNS participants taking GCs at the time of the study compared with controls. In conclusion, GCs in SSNS were associated with significantly greater cortical vBMD and cortical area and lower trabecular vBMD, with evidence of low bone turnover. Lower bone biomarkers were associated with greater cortical vBMD. Studies are needed to determine the fracture implications of these varied effects.     

ACE I/D gene polymorphism in primary FSGS and steroid-sensitive nephrotic syndrome

The role of angiotensin-converting enzyme (ACE) insertion/deletion (I/D) gene polymorphism in various renal disorders has been investigated. We evaluated the association between the clinical characteristics and ACE genotypes of Turkish children with primary focal segmental glomerulosclerosis (FSGS) and steroid-sensitive nephrotic syndrome (SSNS). Patients with FSGS (n=30) were classified into two groups: one with remission together with stable renal function (n=22) and the other without remission and with impaired renal function (n=8). We classified children with SSNS (n=43) that were followed for at least 4 years into two subgroups as having more frequent (n=19) and less frequent relapses (n=11). The DD genotype was more frequent in the SSNS group than that in controls (37% vs. 17%, ²=4.98, P=0.025). However, among SSNS subgroups, the frequency of the DD genotype was not different. The distribution of ACE genotype was similar among patients with FSGS and SSNS. There was no difference in the ACE I/D distribution between children with FSGS and normal controls (II 10%, ID 60%, DD 30% vs. II 13%, ID 70%, DD 17%). The frequency of the DD genotype was higher in FSGS patients with declining renal function (63%) than in those with stable renal function (18%) (P=0.031). Progressive renal impairment was significantly more frequent in patients with FSGS with the homozygous D allele compared with FSGS patients with ID and II genotypes. Our results indicate that the DD genotype may be a risk factor for the development of progressive renal impairment in children with FSGS; however, larger studies are required to confirm this.The abstract of this study was accepted as a poster for the 36th meeting of the European Society of Paediatric Nephrology, Bilbao, September 2002. This study was supported in part by a grant from the Istanbul University Research Fund (no T-849/17072000)     

Heparanase activity is dysregulated in children with steroid-sensitive nephrotic syndrome

BACKGROUND: Immune cells express heparanase, an endoglycosidase, able to degrade heparan sulfate glycosaminoglycan (HSGAG) in the glomerular capillary wall (GCW) and potentially induce proteinuria. The aim of this study was to determine whether dysregulated heparanase expression is associated with the heavy proteinuria of childhood steroid-sensitive nephrotic syndrome (SSNS). METHODS: Plasma and urinary heparanase activity and peripheral blood mononuclear cell (PBMC) mRNA heparanase levels [real-time polymerase chain reaction (PCR)] were measured in children with SSNS in relapse and remission. Plasma and urinary heparanase activity was determined in adult patients with nephrotic syndrome and in age- and gender-matched controls. RESULTS: Plasma heparanase activity was reduced in SSNS with relapse (811.2 units) compared to remission (1147.96 units) (P= 0.003) and control subjects (1390.51 units) (P < 0.001). In adult nephrotic syndrome, plasma heparanase activity was significantly lower in patients compared to controls. However, there was no difference between remission and relapse states. In children, urinary heparanase activity/urinary creatinine ratio was highest in SSNS relapse (14.26 units/mg) compared with remission (7.43 units/mg) (P= 0.016) and controls (2.29) (P < 0.001). However, PBMC heparanase mRNA expression was not different between these three groups. In adult nephrotic syndrome, urinary heparanase activity/urinary creatinine levels were lower in both remission and relapse compared to controls and there was no difference between remission and relapse states. CONCLUSION: In childhood SSNS, there is a qualitative and quantitative difference in urinary heparanase activity expression that is not paralleled in adult nephrotic syndrome. These data suggest that dysregulated heparanase expression may play a significant role in the pathogenesis of SSNS, possibly through an abnormality in post-translational control of latent heparanase activation.     

Familial steroid-sensitive nephrotic syndrome in Southern Israel: clinical and genetic observations

Reports on genetically informative steroid-responsive (sensitive) idiopathic nephrotic syndrome (SSNS) families are lacking. We studied an extended SSNS Bedouin (B) family with a high rate of consanguinity. The clinical presentation and steroid response of its 11 affected individuals were similar to those of sporadic SSNS (spontaneous remission towards puberty and minimal change disease by kidney biopsy). Genome-wide linkage analysis, using a 382 microsatellite-markers mapping set and additional markers adjacent to 80 candidate genes of the index family, did not support linkage to any chromosomal locus. Retrospective analysis of all additional children with SSNS treated by our institution in the past 20 years (n = 96, 50% of them of Jewish origin) revealed another five non-related B families with 2–3 first-degree cousins affected with SSNS in each. The overall familial SSNS rate among the B population (excluding the index family) was 28%, compared with 4% among Jews (Js) (OR 1.8–64, P < 0.005). There were more Bs with simple SSNS than there were Js (71% and 40%, respectively; OR 3.58, 95% CI 1.41–9.23, P < 0.01). In summary, SSNS in this index family was not linked to any of the presently known chromosomal loci nor predicted to be caused by mutation in any one of a list of genes associated with nephrotic syndrome (NS). The presence of other B families affected by SSNS supports the role for susceptibility genes enrichment, exposing highly consanguineous populations to an increased incidence of SSNS. An erratum to this article can be found at     

HLA-DQB1 and DRB1 alleles in Egyptian children with steroid-sensitive nephrotic syndrome

Steroid-sensitive nephrotic syndrome (SSNS) of children has been associated with several HLA-DR and DQ alleles. To investigate this association in Egyptian children, 27 patients with SSNS were typed for HLA-DRB1 and DQB1 alleles using DNA polymerase chain-reverse hybridization technique. The results were compared with 121 healthy subjects for HLA-DRB1 and 59 subjects for DQB1 alleles. We found that: (1) patients have higher frequencies of both DQB1 ^* 0601 (81.5% vs. 10.2% in controls, Pc = 0.0001) and DRB1 ^* 01 (44.4% vs. 3.3% in controls, Pc = 0.00003). Their relative risks are significantly high [38.9, confidence interval (CI) = 10.7–140.7, and 23.4, CI=6.7–81.9, respectively]; (2) the frequency of DRB1 ^* 11 alleles was low in SSNS patients (3.75% vs. 32.2% in controls), but was not significant when P was corrected (P = 0.005, Pc = NS). These findings suggest that DQB1 ^* 0601 and DRB1 ^* 01 or closely associated unknown genes confer susceptibility to SSNS. However, further studies with larger numbers of patients are needed. Received June 27, 1997; received in revised form October 23, 1997; accepted October 26, 1997     

Alterations in proximal femur geometry in children treated with glucocorticoids for Crohn disease or nephrotic syndrome: impact of the underlying disease.

Proximal femur geometry was assessed in children and young adults treated with chronic GCs for CD or SSNS. Subperiosteal width and section modulus were significantly lower in CD and greater in SSNS compared with controls, highlighting the importance of the underlying disease, persistent inflammation, and alterations in lean mass. INTRODUCTION: The impact of glucocorticoid (GC) therapy on bone structure during growth is unknown. Our objective was to characterize proximal femur geometry in children and young adults with Crohn disease (CD) or steroid-sensitive nephrotic syndrome (SSNS) compared with controls and to evaluate the influence of lean mass and GC therapy on bone parameters. MATERIALS AND METHODS: DXA scans of the hip and whole body were obtained in 88 subjects with CD, 65 subjects with SSNS, and 128 controls (4-26 years of age). Hip structural analysis parameters (subperiosteal width, cross-sectional area [CSA], and section modulus in the narrow neck [NN], intertrochanteric region [IT], and femoral shaft [FS]), areal BMD, and whole body lean mass were expressed as Z scores compared with controls. Multivariable linear regression was used to adjust outcomes for group differences in age, sex, race, and height. RESULTS: Mean lean mass Z scores were lower in CD (-0.63, p < 0.001) and greater in SSNS (0.36, p = 0.03) compared with controls. Hip areal BMD Z scores were lower in CD (-0.73, p < 0.001) but not SSNS (-0.02, p > 0.2) compared with controls. In CD, Z scores for subperiosteal width (NN: -1.66, p < 0.001; FS: -0.86, p < 0.001) and section modulus (NN: -0.60, p = 0.003; FS: -0.36, p = 0.03) were significantly lower than controls. In contrast, in SSNS, Z scores were greater for IT subperiosteal width (0.39, p = 0.02), FS CSA (0.47, p = 0.005), and FS section modulus (0.49, p = 0.004). Alterations in section modulus in CD and SSNS were eliminated after adjustment for lean mass. Cumulative GC dose was inversely associated with FS subperiosteal width and section modulus only in CD. CONCLUSIONS: These data show that the effects of GC on proximal femur geometry during growth are influenced by the underlying disease, persistent inflammation, and alterations in lean mass. These data also provide insight into the structural basis of hip fragility in CD.     

Oxidant stress in primary nephrotic syndrome: does it modulate the response to corticosteroids?

In order to assess the oxidative stress in newly diagnosed children with primary nephrotic syndrome (PNS), we serially measured serum total antioxidant capacity (TAC) and malondialdehyde (MDA) in 33 children with PNS and ten healthy matched controls. Patients were classified into two groups: those who had steroid-sensitive nephrotic syndrome (SSNS; n = 26) and those who had steroid-resistant nephrotic syndrome (SRNS; n = 7). Of the patients with SSNS, 15 were non-relapsers and 11 were relapsers. At the proteinuric phase, all patients had significantly higher MDA levels and lower TAC than the controls. These changes were more marked in patients with SRNS than in those with SSNS. During remission and still on corticosteroids, patients had higher TAC and similar MDA levels as in the proteinuric phase, but the TAC and MDA levels still significantly differed from those of the controls. More improvement in TAC and MDA levels occurred in patients following the weaning of corticosteroids, but TAC was still lower in the patients than in the controls. Moreover, TAC was higher in non-relapsers than in relapsers. Using a receiver operating characteristic curve, the initial response to corticosteroids could be predicted at serum TAC level ≥0.73 mM/L (sensitivity 89%, specificity 86%), while serum TAC levels ≤ 1.14 mM/L after the weaning of corticosteroids could predict that the patient would not relapse (sensitivity 91%, specificity 80%). In conclusion, based on our results, PNS can be considered to be associated with oxidative stress even during remission. This stress may modulate the response to corticosteroids. Further prospective studies using larger numbers of patients are needed to validate these results.     

Proteomic profiling identifies haptoglobin as a potential serum biomarker for steroid-resistant nephrotic syndrome

Background: Long-term outcomes for patients with adult idiopathic nephrotic syndrome correlate closely with steroid responsiveness. The aim of this prospective study was to evaluate the difference in serum proteomes between steroid-sensitive nephrotic syndrome (SSNS) and steroid-resistant nephrotic syndrome (SRNS) patients and identify potential biomarkers for the prediction of SRNS. Methods: We performed a gel-based proteomic study of serum obtained from SRNS and SSNS patients and healthy controls at the time of presentation (n = 6 for each group). Proteins from the serum samples were separated using 2-D electrophoresis, digested in-gel and subjected to MALDI-TOF-MS/MS analysis. Further validation was performed utilizing Western blot and ELISA. The sensitivities and specificities of the candidate proteins for predicting SRNS were determined using receiver operating characteristic curves. Results: Thirteen differentially expressed proteins were identified as haptoglobin (Hp) with different isoelectric points and molecular weights. Western blot and ELISA analysis of samples from 146 subjects (healthy controls = 52, SSNS = 54, SRNS = 40) showed a markedly increased level of Hp in the serum, but not urine, of SRNS compared to SSNS patients. The optimal serum cutoff level of Hp was set at ≥1,279 μg/ml using the receiver operating characteristic curve. The sensitivity and specificity for predicting SRNS were 85.0 and 96.3%, respectively. Conclusions: This study provides a novel overview of the difference in serum proteomes of SSNS and SRNS patients. Serum Hp may be a useful predictive biomarker for steroid therapy efficacy in the treatment of idiopathic nephrotic syndrome.     

Combined T- and B-cell activation in childhood steroid-sensitive nephrotic syndrome

BACKGROUND: Growing evidence shows that steroid-sensitive nephrotic syndrome (SSNS) is the result of a primary T-cell disturbance and leads to secondary anatomical and functional, however, not to immunological glomerular changes. In addition, immunoglobulin abnormalities in SSNS indicate a role of B-cell involvement. PATIENTS AND METHODS: We therefore analyzed T- and B-cell activation markers in children with SSNS at different stages of the disease including different treatment regimens by measuring the soluble IL-2 receptor (sCD25) and the soluble low-affinity IgE receptor (sCD23), respectively. Seventy-five patients with SSNS (median age 8.0, range 2.5 - 18 years) were studied, 33 in relapse (RL) including 21 patients relapsing during alternate-day steroids (RL-SD). Forty-two patients were studied in remission (RM; 14 off treatment and 28 on alternate-day steroids (RM-AD)) and 22 age-matched children served as controls. RESULTS: Serum concentrations of sCD25 were increased in RL (113.6 +/- 19.5 micromol/l) compared to RM (79.8 +/- 8 micromol/l, p < 0.02) and controls (74.8 +/- 0.9 micromol/l, p < 0.02). Patients with RL-SD did not have elevated sCD25. In relapse, sCD25 was inversely correlated with age (R = -0.36, p < 0.04) and positively correlated with total IgG (R = 0.37, p < 0.04). Urinary excretion of sCD25 was also significantly elevated in RL of SSNS compared to RM and controls (71.2 +/- 11.9 micromol/g creatinine vs. 39.1 +/- 4.8 and 32.0 +/- 4.2 micromol/g, p < 0.05). Serum levels of sCD 23 were significantly elevated in RL (6.22 +/- 0.65 microg/l) compared to RM (3.1 +/- 0.83 microg/l, p < 0.02) and to controls (3.4 +/- 0.93 microg/l). The highest values, however, were found in RL-SD (7.8 +/- 1.7 microg/l) vs. untreated RL (p < 0.007) and RM-AD (p < 0.002). In untreated RL there was a significant correlation of sCD23 and total IgE (R = 0.67, p < 0.02) and in RL-SD with total IgG (R = 0.45, p < 0.05). sCD23 and sCD25 were not correlated with each other. CONCLUSION: These data document parallel abnormalities of both CD23-mediated B as well as CD25-mediated T-cell activation and suggest that SSNS is not solely a disorder of T-cell dysfunction.     

Interleukin-12 and interferon-γ production in childhood idiopathic nephrotic syndrome

Cellular immune disturbances, and T lymphocyte function in particular, have been previously implicated in idiopathic nephrotic syndrome (INS) of childhood. There are different patterns of cytokine expression in various forms of glomerulonephritis, which suggests that local production of these peptides plays an important role in the pathogenesis and progression of glomerulonephritis. To investigate T-cell and monocyte/macrophage cytokine production in INS, interleukin-12 (IL-12) and interferon-γ (IFN-γ) production by peripheral blood mononuclear cells (PBMC) of 11 children with steroid-sensitive nephrotic syndrome (SSNS), 9 with focal segmental glomerulosclerosis (FSGS), and 17 healthy controls was determined. Children with SSNS were studied in relapse, during corticosteroid treatment, and in stable remission, off corticosteroid treatment. IL-12 was not detected in serum, urine, and in supernatants of unstimulated PBMC. IL-12 production by concanavalin A (Con A)-stimulated PBMC of children with SSNS and FSGS was not different from controls. IFN-γ production by Con A-stimulated PBMC was decreased in children with relapsing SSNS, both in relapse and and during corticosteroid treatment. However, in stable remission it was similar to controls. Markedly decreased IFN-γ production (P<0.001) was observed by pokeweed mitogen-stimulated PBMC of relapsing SSNS patients and moderately decreased production by PBMC of FSGS patients. This study has established a decreased production of IFN-γ by PBMC of relapsing SSNS and FSGS patients, but does not allow differentiation between these two different conditions. IL-12 did not have a pathogenic role in either SSNS or FSGS. Received May 24, 1997; received in revised form March 19, 1998; accepted March 23, 1998     

Varicella vaccination in children with steroid-sensitive nephrotic syndrome

We have studied serological and clinical response to live, attenuated varicella zoster virus (VZV) vaccine (Varilrix, SmithKline Beecham) in 20 patients with steroid-sensitive nephrotic syndrome (SSNS) in remission and 22 normal controls who had no history of varicella and no detectable antibody to VZV. Nephrotic patients included 15 boys and 5 girls, with a mean age of 4.7 years (range 2–11.4 years). The controls were healthy age-matched children (13 girls and 9 boys). Seventeen patients with SSNS (85%) and 19 healthy controls (86%) seroconverted 8 weeks after vaccination. One patient with SSNS had a relapse 20 days after vaccination, and 1 child in the control group had a rash. Two years after vaccination, antibodies to VZV were detected in 12 of 17 responders, 2 of 3 non-responders, and 13 of 22 controls. Within 2 years of vaccination, 3 of the vaccine responder children with SSNS had a mild varicella infection. Two responder and 1 non-responder nephrotic children and 9 controls were lost to long-term follow-up. Our results show that immunization with a single dose of VZV vaccine is safe and effective in children with SSNS in remission. Received: 9 May 2001 / Revised: 15 November 2001 / Accepted: 18 November 2001     

5-Lipoxygenase and leukotriene A<Subscript>4</Subscript> hydrolase expression in primary nephrotic syndrome

Gene expression of 5-lipoxygenase (5-LO) and leukotriene A₄ (LTA₄) hydrolase was analyzed in the peripheral blood of 48 children with active primary nephrotic syndrome (PNS) (group I), 27 children with PNS in remission (group II), and 20 controls. Group I included 34 patients with steroid-sensitive PNS (SSNS) and 14 patients with steroid-resistant PNS (SRNS). Total RNA purified from peripheral blood mononuclear (PBMN) cells was reverse transcribed into cDNA and amplified with specific primers in the polymerase chain reaction. All group I patients and none of the controls expressed 5-LO and LTA₄ hydrolase. Of group II children, 22.2% expressed 5-LO, while 51.9% expressed LTA₄ hydrolase. Among group I patients there was a significant positive correlation between the degree of proteinuria and the expression of 5-LO (r=0.27, P=0.03) and LTA₄ hydrolase (r=0.44, P=0.001). There was no difference in the degree of expression of both enzymes between SSNS and SRNS patients. In conclusion, leukotrienes may play a role in the pathogenesis of PNS in children, but they do not participate in the response of these patients to steroids.     

Serum levels of immunoglobulins and IgG subclasses in steroid sensitive nephrotic syndrome

Alterations of serum immunoglobulins, especially hypogammaglobulinemia (HG), are a frequent finding in steroid sensitive nephrotic syndrome (SSNS). The exact mechanisms are unclear, especially the persistence of HG into remission. Therefore we studied serum immunoglobulins M, A and G including IgG subclasses 1–4 in 44 children with SSNS; 14 were studied during relapse (RL) and 30 in remission (RM). Data were compared with those of 23 healthy controls. In a subgroup of 23 patients (12 in RM and 11 in RL) we also studied IgG-1 specific antibodies to tetanus toxoid and IgG-2 specific antibodies to pneumococcus antigen. Increased serum concentrations of IgM in RL and reduction of serum IgG in RL and RM were confirmed. During relapse, HG was characterized to result from deficiency of IgG-1–3, whereas in early phases of relapse the reduction was due to low IgG-1 only. In RM the deficiency of IgG-2 persisted for 12 months and correlated strongly with the duration of remission (R=0.60, P<0.0001). IgG-4 levels were not altered in SSNS. In addition, IgG-2 specific antibodies to pneumococcus antigen were significantly reduced only in RL compared to RM (P<0.05). In conclusion, hypogammaglobulinemia of SSNS is characterized by a different constitution of IgG subclasses. In RL a reduction of serum levels of IgG-1–3 occurs, while low concentrations of IgG-2 might be the explanation for HG in remission of SSNS. Received: 3 October 2001 / Revised: 6 December 2001 / Accepted: 7 December 2001     

Mutational analysis of <Emphasis Type="Italic">NPHS2</Emphasis> and <Emphasis Type="Italic">WT1</Emphasis> in frequently relapsing and steroid-dependent nephrotic syndrome

Idiopathic nephrotic syndrome is a common pediatric kidney disease, 80% of all cases are steroid sensitive (SSNS). A significant proportion of children with SSNS will have a frequently relapsing or steroid-dependent course (FRNS/SDNS) that is associated with significant treatment-related morbidity. Mutations in NPHS2 account for more than 28% of all cases of steroid-resistant nephrotic syndrome (SRNS) and dominant mutations in WT1 for 5%; while mutations are absent from children with uncomplicated SSNS. Since FRNS/SDNS is phenotypically positioned within a spectrum between SSNS and SRNS, we hypothesized that heterozygous mutations of NPHS2 may be causing FRNS/SDNS. Mutational analysis of NPHS2 and WT1 was carried out in a single-center cohort of 20 children with FRNS/SDNS, ten children with uncomplicated SSNS (control), and 22 children with SRNS (control). Renal biopsy findings were available in 15/20 children with FRNS/SDNS and revealed IgM nephropathy, MCNS, and FSGS in six, five, and four children, respectively. Children with FRNS/SDNS were significantly younger at first presentation than those with SSNS and SRNS (median age: 3.0 years in FRNS/SDNS patients, 7.0 years in SSNS patients, and 5.0 in SRNS patients; p < 0.001). No NPHS2 or WT1 mutations were found in patients with FRNS/SDNS and uncomplicated SSNS. The hypothesis that FRNS/SDNS may be associated with heterozygous mutations in NPHS2 or WT1 was not confirmed.     

Vitamin D insufficiency in steroid-sensitive nephrotic syndrome in remission

Serum 25-hydroxyvitamin D [25(OH)D] concentrations are the best indicator of vitamin D nutritional status. We measured serum 25(OH)D concentrations in 94 healthy controls and in 41 subjects (aged 4–22 years) with steroid-sensitive nephrotic syndrome (SSNS) in remission. Children with remitted SSNS had significantly lower 25(OH)D concentrations than healthy controls (median 16.4 ng/ml versus 23.9 ng/ml, P <0.001). In a multivariable logistic regression model, the odds ratios (OR) of vitamin D insufficiency [25(OH)D <20 ng/ml] were independently increased in SSNS subjects [OR 11.2 (95% confidence interval 3.5–36.2)], non-whites [OR 12.9 (4.6–36.2)], older children [OR 1.20 per year (1.06–1.36)], and winter months [OR 6.7 (2.5–18.4)]. Within the SSNS subjects, multiple linear regression determined that serum 25(OH)D concentrations were not associated with SSNS disease characteristics measured in this study, such as duration of disease, number of relapses, cumulative glucocorticoids, and interval since last relapse. In conclusion, children with remitted SSNS have lower serum 25(OH)D concentrations than healthy controls. This difference persisted after adjusting for the potential confounding effects of age, race, season, and milk intake. Children with remitted SSNS may benefit from routine measurement of 25(OH)D, but the clinical significance of low 25(OH)D in this population remains unclear.     

Efficacy of zinc supplements in reducing relapses in steroid-sensitive nephrotic syndrome

Relapses in steroid-sensitive nephrotic syndrome (SSNS) often follow infections of the respiratory or gastrointestinal tract. Based on data that zinc supplements reduce the risk of infections, we examined the efficacy of such supplements in reducing relapse rates in these patients. Eighty-one patients with SSNS (1–16 years old) were stratified into frequent (n = 52) and infrequent (n = 29) relapsers and randomized to receive 12-months of therapy with the recommended dietary allowance of zinc (10 mg/day) (n = 40) or placebo (n = 41). Patients with frequent relapses also received long-term, alternate-day prednisolone. Subjects receiving zinc showed a 20% lower frequency of relapses, with 44.7% of the patients having sustained remission compared to 27.5% in the placebo group (P > 0.05). Patients with frequent relapses receiving zinc showed a 28% reduction in relapse rates and a significantly higher likelihood of sustained remission (P = 0.02). Findings from this double blind, randomized study suggest that zinc supplementation results in trends towards remission and reduced relapses, especially in patients with frequent relapses. Prospective, adequately powered studies are required for confirmation of these findings. Cochrane Renal Group Registry (CRG030600044)     

Stem cell mobilization in idiopathic steroid-sensitive nephrotic syndrome

Steroid-sensitive nephrotic syndrome (SSNS) is classically thought to be a T-cell disorder. The aim of this study was to examine whether or not thymus homeostasis was affected in SSNS. Mature and naive T cell recent thymic emigrants were quantified in the peripheral blood of nephrotic patients and controls. Because the generation of new T cells by the thymus ultimately depends on hematopoietic stem cells, CD34+ cells were also included in the study. Nineteen patients with SSNS during relapse, 13 with SSNS during proteinuria remission, and 18 controls were studied. Cell-surface markers (CD3, CD4, CD8, CD19, CD16, CD56, CD45RA, CD62L, CD34, and CD38) were analyzed by flow cytometric analysis. T-cell rearrangement excision circles (TRECs) were quantified in CD2+ cells by real-time polymerase chain reaction. Stroma cell-derived factor-1 (SDF-1) genotype and metalloproteinase-9 (MMP-9) plasma levels were also determined. Mature T cells (CD4+ and CD8+), circulating naive T cells (CD62L+ and CD3+ CD62L+), and recent thymic emigrants (CD45RA+) as well as TRECs, that measure thymus production, had a similar level in the three groups of patients. Conversely, CD34+ hematopoietic stem cells displayed a two-fold increase in SSNS patients during relapse either compared with controls or SSNS patients at remission. In addition, compared with controls, SSNS patients at remission displayed (1) a decrease in CD19+ cells (B cells) and (2) an increase in CD16CD56+ cells [natural killer (NK) cells]. In conclusion, thymus homeostasis is not significantly affected in nephrotic patients. Hematopoietic stem-cell mobilization at proteinuria relapse, as well as changes in B and NK cells during remission, suggest that SSNS might be due to a general disturbance of hematopoietic and immune cell trafficking.     

Low expression of glucocorticoid receptors in children with steroid-resistant nephrotic syndrome

Background

About 10–20 % of children with idiopathic nephrotic syndrome (NS) are steroid-resistant (SR). Low expression of glucocorticoid receptors (GRs) has been associated with poor response to steroids in a variety of autoimmune diseases. This study was done to assess the expression of cytoplasmic GRs for CD3 and CD14 in children with NS.

Methods

Expression of cytoplasmic GRs in lymphocytes (CD3⁺/GR) and monocytes (CD14⁺/GR) in the peripheral blood were assessed in 51 children with NS before the start of therapy by flow cytometry. Patients were divided into two groups: 30 children who were steroid-sensitive (SSNS) and 21 children who had initial steroid resistance (SRNS). Twenty age- and sex-matched healthy children served as controls.

Results

Expression of CD3⁺/GR was significantly lower in SRNS in comparison to SSNS patients and controls (p?<?0.0001). Similarly, expression of CD14⁺/GR was significantly lower in SRNS in comparison to SSNS patients (p?<?0.0001) and controls (p?=?0.002). CD3⁺/GR and CD14⁺/GR expression were not significantly different in SSNS patients compared with controls (p?=?0.06 and 0.07 respectively).

Conclusions

Patients with initial SRNS showed decreased GR expression in peripheral blood mononuclear cells (PBMC) before starting therapy, and this low expression may be one of the pathophysiological mechanisms of steroid resistance in these children.     

Lymphocyte subpopulations,interleukin-2 and interleukin-2 receptor expression in childhood nephrotic syndrome

Abnormal T lymphocyte function and reduced interleukin-2 (IL-2) production have been implicated in the pathogenesis of the nephrotic syndrome (NS). We investigated: (1) lymphocyte subpopulations and expression of IL-2 receptor (IL-2R) on T cells using two-colour flow cytometry, (2) serum IL-2 and (3) the soluble component of IL-2R (sIL-2R) in serum, using enzyme-linked immunosorbent assay, in 38 children with NS. All children, except those in remission, had marked proteinuria. They were divided into groups according to renal pathology: (1) steroid-sensitive NS (SSNS) not receiving prednisolone therapy, (2) SSNS on prednisolone, (3) focal segmental glomerulosclerosis (FSGS), (4) SSNS in remission and not receiving prednisolone therapy, (5) congenital NS (CNS). Results were compared with 26 age-matched controls. Total T lymphocytes (CD3) were reduced in groups 1 and 2; CD4 count was reduced in groups 1–4; CD8 count increased in groups 2 and 3; CD8 and CD19 (B lymphocytes) were significantly reduced in group 5. Increased IL-2R expression (CD25) on CD4 lymphocytes was noted in groups 1, 2 and 3 implying activation of these cells. In patients with SSNS, increased serum sIL-2R was recorded during relapse (1,273±497 U/l vs. 913±401 U/l in remission,P<0.005) but free serum IL-2 was not detectable at any stage. The specific alterations in lymphocyte subpopulations in SSNS and FSGS would imply an involvement of the immune system distinct from that in CNS.     

Is HLA-DR6 a protective factor against posttransplantation diabetes mellitus?

BACKGROUND: Posttransplant diabetes mellitus (PTDM) has several pre- and posttransplant risk factors. METHODS: The incidence and risk factors of PTDM were retrospectively evaluated in 2117 kidney allograft recipients from June 1984 to March 2004. Type and dosage of immunosuppressive agents, pretransplant weight and human leukocyte antigen (HLA) phenotypes in PTDM patients were compared with 61 matched controls. RESULTS: Sixty-one cases (2.8%) developed PTDM requiring insulin or oral hypoglycemic therapy, out of which 47.5% were men and 52.5% were women, although only 35% of our overall recipients are women. Onset occurred at a mean of 489 days following transplantation. Patients receiving more than 15 mg/d prednisolone developed PTDM more often than those on less than 15 mg/d (P = .000). Similarly PTDM was more frequent among patients who received more than 300 mg/d cyclosporine compared with those on less than 300 mg/d (P = .015). Mean weight in PTDM cases and controls was 65 +/- 13.4 kg and 57 +/- 13.6 kg, respectively (P = .005). HLA-DR6 was observed in 12.2% of nonaffected subjects but in none of the PTDM group (P = .002). Conversely, HLA-DR8 was seen only in PTDM patients (P = .012). In addition HLA-A26 was more common among PTDM patients (P = .02) and HLA-DR52 more frequent in nonaffected subjects (P = .025). CONCLUSION: Our findings suggest that female sex, dosages of prednisolone and cyclosporine, pretransplant weight, and genetic factors are associated with an increased risk of PTDM. The rate of PTDM appeared to be independent of weight gain in the first year posttransplant. Protection against PTDM may be afforded by HLA-DR6 and possibly HLA-DR52. Conversely and higher incidence of diabetes has been associated with HLA-DR8 and HLA-A26.