Genome-wide association analyses define pathogenic signaling pathways and prioritize drug targets for IgA nephropathy

IgA nephropathy (IgAN) is a progressive form of kidney disease defined by glomerular deposition of IgA. Here we performed a genome-wide association study of 10,146 kidney-biopsy-diagnosed IgAN cases and 28,751 controls across 17 international cohorts. We defined 30 genome-wide significant risk loci explaining 11% of disease risk. A total of 16 loci were new, including TNFSF4/TNFSF18, REL, CD28, PF4V1, LY86, LYN, ANXA3, TNFSF8/TNFSF15, REEP3, ZMIZ1, OVOL1/RELA, ETS1, IGH, IRF8, TNFRSF13B and FCAR. The risk loci were enriched in gene orthologs causing abnormal IgA levels when genetically manipulated in mice. We also observed a positive genetic correlation between IgAN and serum IgA levels. High polygenic score for IgAN was associated with earlier onset of kidney failure. In a comprehensive functional annotation analysis of candidate causal genes, we observed convergence of biological candidates on a common set of inflammatory signaling pathways and cytokine ligand-receptor pairs, prioritizing potential new drug targets.

Long-term renal outcome in children with OCRL mutations: retrospective analysis of a large international cohort

Background

Lowe syndrome (LS) and Dent-2 disease (DD2) are disorders associated with mutations in the OCRL gene and characterized by progressive chronic kidney disease (CKD). Here, we aimed to investigate the long-term renal outcome and identify potential determinants of CKD and its progression in children with these tubulopathies.

Methods

Retrospective analyses were conducted of clinical and genetic data in a cohort of 106 boys (LS: 88 and DD2: 18). For genotype-phenotype analysis, we grouped mutations according to their type and localization. To investigate progression of CKD we used survival analysis by Kaplan-Meier method using stage 3 CKD as the end-point.

Results

Median estimated glomerular filtration rate (eGFR) was lower in the LS group compared with DD2 (58.8 versus 87.4 mL/min/1.73 m2, P < 0.01). CKD stage II-V was found in 82% of patients, of these 58% and 28% had moderate-to-severe CKD in LS and DD2, respectively. Three patients (3%), all with LS, developed stage 5 of CKD. Survival analysis showed that LS was also associated with a faster CKD progression than DD2 (P < 0.01). On multivariate analysis, eGFR was dependent only on age (b = -0.46, P < 0.001). Localization, but not type of mutations, tended to correlate with eGFR. There was also no significant association between presence of nephrocalcinosis, hypercalciuria, proteinuria and number of adverse clinical events and CKD.

Conclusions

CKD is commonly found in children with OCRL mutations. CKD progression was strongly related to the underlying diagnosis but did not associate with clinical parameters, such as nephrocalcinosis or proteinuria.

Therapeutic Plasma Exchange in Pediatric Renal Transplantation Experience of One Decade and 389 Sessions

OBJECTIVE

There are no specific recommendations for therapeutic plasma exchange (TPE) in children after renal transplantation. The purpose of this study was to report the experience with TPE in a pediatric transplant setting.

MATERIALS AND METHODS

59 patients (mean age 12.5 ± 4.5 years) undergoing renal transplantation. Indications for TPE included the recurrence of nephrotic syndrome (NS; n = 30) and atypical hemolytic uremic syndrome (n = 6), chronic antibody-mediated rejection (cAMR; n = 20), sensitization (n = 2), and immune thrombocytopenia (n = 1). The single-filtration TPE was performed in all cases. In 74.7% of patients, fresh frozen plasma was used as a replacement fluid. In 25.3% of patients, 4% albumin solution was used as a replacement fluid. Criteria for TPE efficacy included a decrease of proteinuria and normalization of renal function in NS; a normalization of platelet count, C3, and hemoglobin concentration in aHUS; improvement in renal function; and reduction of donor-specific antibodies in cAMR; and removal of antiplatelet antibodies in immune thrombocytopenia.

RESULTS

Efficacy results for patients with NS: 59.3% achieved remission, 25.9% achieved partial remission, and 14.8% achieved no remission, respectively. For patients with atypical hemolytic uremic syndrome there was remission in 66.6% and no remission in 33.4%. For patients with cAMR there was remission in 75% and no remission in 25%. Antiplatelet antibodies disappeared after TPE in 1 patient. In 9% of TPE procedures, minor complications were noted. All patients were on posttransplant maintenance immunosuppression and several children received additional treatment (intravenous immunoglobulin therapy or rituximab) during TPE therapy.

CONCLUSION

TPE therapy (combined with immunosuppression) was an effective tool in most pediatric cases after renal transplantation with low incidence of minor adverse events.

Evaluation of the effect of 3-month bladder basic advice in children with monosymptomatic nocturnal enuresis

INTRODUCTION

Advice (BBA) into the standards of patients' care in both monosymptomatic and non-monosymptomatic nocturnal enuresis. Although the idea of this recommendation was clear and reflects clinical experience, duration and efficacy have not been definitely established. Recent data have demonstrated the lack of efficacy of BBA and a fierce discussion has ensued. The present study was aimed to assess the efficacy of BBA in a group of previously untreated children with primary monosymptomatic nocturnal enuresis (MNE).

STUDY DESIGN

The study was a prospective interventional multicenter trial in a cohort of previously untreated MNE patients. Forty-nine children (36 males, 13 females, mean age 7.2 years) were included in the analysis. The treatment efficacy was assessed at the 30th, 60th, and 90th days of BBA.

RESULTS

We discovered that the mean number of wet nights decreased significantly (p < 0.001) only after 3 months of BBA from 8.9 to 5.9 episodes every 2 weeks. BBA was fully successful in 2% o the children after 30 day, 12% after 60 days, and 18% after 90 days (Figure). Partial response (by ICCS) was assessed for 8%, 20%, and 34% of the patients. We noted a relatively high rate of non-responders that decreased from 90% to 47% after 90 days. We detected no differences in BBA efficacy between children with night-time polyuria or decreased maximal voided volume. A lower number of wet nights initially predicted the response to the BBA.

DISCUSSION

Our study confirmed rather limited efficacy of BBA, similarly to previous observations, but provided more information on isolated MNE, because of a more specific study group and longer period of observation. The limitation of the study was lack of randomization.

CONCLUSION

Our study revealed that in treatment-naïve children with monosymptomatic enuresis basic bladder training had a low (18%) and late effect, mostly pronounced after the third month of therapy. It seems that only if the patient presents with a favorable profile of bedwetting, occasionally and with a high maximum voided volume, it is worth maintaining BBA for a longer period of up to 3 months before initiating second-line therapy. In an unfavorable initial profile desmopressin or an alarm may be introduced much earlier.

Anaemia treatment in chronically dialysed children: a multicentre nationwide observational study

OBJECTIVE

Erythropoiesis-stimulating agents (ESAs) are applied as a standard therapy in children with anaemia in chronic kidney disease. The aim of this study was to describe the efficacy and details of ESA treatment in a population of dialysed children in Poland.

MATERIAL AND METHODS

The study had a prospective observational design and was performed in 12 dialysis centres. The study group comprised 117 dialysed children with a mean age at enrolment of 165.33 (97.18-196.45) months.

RESULTS

Dialysed children were treated mostly with epoietin beta and darbepoietin. The mean dose of ESA was 99 (68-147) U/kg/week with a significant difference between patients on peritoneal dialysis [83 (54-115)] and haemodialysis [134 (103-186)] (p < 0.0001). The mean haemoglobin of all the time-point tests during 6 months was 10.91 ± 1.18 g/dl. The efficacy of anaemia treatment was unsatisfactory in 52% of subjects. In multivariate analysis, initial haemoglobin level <10 g/l, any infection, younger age at first dialysis, malnutrition and inadequate ESA dosage remained significant predictors of anaemia.

CONCLUSIONS

The study revealed that anaemia treatment in Polish children is unsatisfactory. Late commencement of the treatment, inadequate dosing, malnutrition and infections could constitute risk factors for therapy failure.

[Xanthinuria type I as the cause of nephrolithiasis in 17-years old girl]

Classic xanthinuria is a rare metabolic defect concerning the final reactions of purine catabolism. There are two types of the disorder: type I results from xanthine dehydrogenase (XDH) deficiency, while type II is characterized by lack of both XDH and aldehyde oxidase activity. Both types are clinically similar and are characterized by elevated xanthine concentration in body fluids that can lead to xanthine crystallisation. The most common manifestation of the disease is urolithiasis, but in most cases xanthinuria remains asymptomatic and the diagnosis is accidental. In the paper we report the first case study of xanthinuria in Poland in a child presenting with urolithiasis. 17-years old female patient was diagnosed because of recurrent urinary lithiasis and hypouricemia was detected during routine tests. Plasma and urine concentrations of oxypurines were measured by high-performance liquid chromatography (HPLC) and showed typical features of xanthinuria: hypouricemia, hypouricosuria, xanthinuria and elevated plasma xanthine. The allopurinol loading test demonstrated type I xanthinuria. The presented case report supports that first symptoms of xanthinuria can appear at any age and this disorder should be considered during diagnosing urolithiasis.

[Cinacalcet in the treatment of secondary hyperparathyreoidism in a child with chronic kidney disease--case report]

The medical history and treatment of 2.5 years old girl with chronic kidney disease and heavy hyperparathyreoidism was presented in this case report. This girl was treated by peritoneal dialysis (APD) due to chronic kidney disease and congenital nephrotic syndrome. The secondary paraidothyreoidism was a reason of the epiphysial of the upper end of the femur, which appeared despite of the treatment by the Vitamin D3 (Calciphediol and Alphacalcidol) and phosphate binding drugs like Calcium Carbonate and Sevelamer. The primary laboratory tests were: Ca 9.32 mg/dl, Ca jon. 1.21 mmol/l, PO4 7.29 mg/dl, BE +4.9 mmol/l, ALP 1425 U/l, PTH 3774 pg/ml, Albumins 3.23 g/l, Hgb 8.2 g/l. The treatment of cinacalcet (Mimpara, 30 mg, Amgen) in dose of 15 mg was started because of lack of the standard therapy results. The laboratory tests were controlled after 2 weeks and then every week to 5th and every 2 weeks to the end. This therapy was finished after 30 weeks and only the standard therapy of hyperphosphatemia was continued. The laboratory tests 3 month after stopped the treatment were: Ca 10.5 mg/dl, Ca jon. 1.36 mmol/l, PO4 4.0 mg/dl, BE +4.9 mmol/l, ALP 312 U/l, PTH 134 pg/ml, Albumins 3.23 g/l, Hgb 9.9 g/l. There were any adverse events observed during the treatment.

CONCLUSION

It seems, the cinacalcet may be an alternate treatment to paraidectomy in children with chronic kidney disease and heavy secondary hyperparathyreoidism.

[The use of sevelamer in the treatment of resistant hyperphosphataemia in children with chronic renal disease]

The aim of study was the estimation of efficacy and safety of sevelamer treatment in children with chronic kidney disease with resistant hyperphsphatemia.

MATERIAL AND METHODS

The study group was 7 patients (hemodialysed--2 boys, mean age 7, 7+/-0.1; peritoneal dialysis--5: 3 boys and 2 girls, mean age 5, 6+/-5.0). Sevelamer (Renagel, 800 mg, Genzyme) was used in all patients in mean dosis of 117 mg/kgm.c./d due to lack of effect of the typical treatment (vitamin D, diet, calcium carbonate). Results of treatment by sevelamer were estimated by measuring of calcium, phosphates, albumins, parathormone and alkalic phosphate concentration in the serum and blood gases after 6 and 12 month.

RESULTS

There were found that sevelamer treatment significantly decrease the phosphates concentration and CaxP product in the serum without influence on concentration of PTH or calcium. Any adverse events were observed during the study and any drug intolerance.

CONCLUSION

Sevelamer treatment may be usefulness in children with resistant hyperphosphatemia.

Hypertension in dialysed children: the prevalence and therapeutic approach in Poland--a nationwide survey

BACKGROUND

The aim of this nationwide analysis was to assess the incidence and current treatment profile of arterial hypertension in children undergoing chronic haemodialysis or peritoneal dialysis and attitudes of paediatric nephrologists towards the choice of antihypertensive drugs in their patients.

METHODS

The study group consisted of 134 children (89 males, 45 females, mean age 10.7+/-5 years) from all 13 paediatric dialysis centres in Poland. The data were gathered through a questionnaire for each patient dialysed in November 2004.

RESULTS

The overall incidence of hypertension in the study group was 55% (74 of 134 patients; 47 males, 27 females). The incidence rate was similar in boys and girls (53 vs 60%) and in those on haemodialysis and peritoneal dialysis (56 vs 54%). Chronic glomerulonephritis as an underlying renal disease was significantly more frequent in the hypertensive than in the normotensive subjects (37 vs 10%, P = 0.004). Residual urine output was higher in normotensives (41 vs 10 ml/kg body weight; P < 0.001). Among those treated with antihypertensives: 32% were treated by monotherapy, 36% received two drugs, 22% received three drugs, while 7% received > or = 4 drugs. The therapy was effective in only 57% of subjects. We observed no differences in biochemical and clinical parameters between those who responded to the therapy and those who failed to do so. Calcium channel blockers constituted the most frequently administered class of drugs [73% of children; in 43 out of 48 (90%) combined with other drugs, but in 11 out of 24 (46%) as a monotherapy]. In monotherapy, angiotensin-converting enzyme inhibitors and calcium channel blockers were administered most frequently.

CONCLUSION

We conclude that the incidence of hypertension in dialysis children in Poland is high (55%). The effectiveness of antihypertensive treatment is rather low (58%) and the choice of drugs is limited.

Abnormal Cytokine Synthesis as a Consequence of Increased Intracellular Oxidative Stress in Children Treated with Dialysis

BACKGROUND/AIM

End-stage renal disease (ESRD) induces a clinical state of immunodeficiency with a higher incidence of infections and higher mortality due to infectious complications compared with the normal population. The definite mechanism responsible for the host defense alterations is not well understood. The aim of the study was to investigate intracellularly the relationship between cytokine synthesis and oxidative stress in peripheral blood lymphocytes in children with ESRD.

METHODS

Twenty-one children (age 11.7 +/- 5.8 years) with ESRD treated with hemodialysis (HD; n = 10) and peritoneal dialysis (PD; n = 11) were studied. Nine healthy children of comparable age formed the control group. To determine intracellular oxidative stress we used dihydrorhodamine-123 (DHR), which after oxidation to rhodamine-123 (RHO) emitted a bright fluorescent signal. Intracellular oxidation of DHR in T lymphocytes reflected intracellular oxidative stress. The intracellular synthesis of cytokines (IL-2, IFN-gamma, IL-4, IL-6) was also measured. Both parameters were detected at a single-cell level by flow cytometry. Lymphocyte subsets were evaluated using the monoclonal antibodies conjugated with fluorochromes.

RESULTS

We found that in T lymphocytes the mean fluorescence intensity (MFI), which reflected intracellular oxidative stress, was increased in ESRD patients compared to the controls (CD3+: 34.77 +/- 11.55 vs. 22.55 +/- 4.97, p < 0.01; CD3+CD8+: 34.31 +/- 12.17 vs. 20.77 +/- 4.89, p < 0.01; CD3+CD4+: 36.06 +/- 6.98 vs. 24.44 +/- 7.68, p < 0.001). HD patients showed slightly higher MFI compared to PD patients in CD3+ cells (39.32 +/- 11.70 vs. 30.63 +/- 10.20, NS), in CD3+CD8+ cells (37.90 +/- 14.32 vs. 31.06 +/- 9.34, NS) and in CD3+CD4+ cells (40.10 +/- 2.28 vs. 29.33 +/- 7.06, p < 0.001). The intracellular synthesis of IL-2 was higher in ESRD patients compared to the controls, both in CD3+ cells (31.34 +/- 9.80 vs. 20.49 +/- 15.26%, p < 0.05) and in CD3+CD4+ cells (36.10 +/- 8.69 vs. 24.03 +/- 16.95%, p < 0.05). The intracellular synthesis of IFN-gamma, IL-4 and IL-6 was significantly lower in the ESRD group compared to the controls. Interestingly, in patients treated with HD, negative correlations between the degree of intracellular oxidative stress and intracellular cytokine synthesis in CD3+ lymphocytes were found.

CONCLUSION

Our results show that patients with ESRD, especially those treated with HD, present increased oxidative stress in T lymphocytes, which may lead to decreased cytokine synthesis and abnormal immune response.

[Yersiniosis as a cause of acute tubulointerstitial nephritis and acute renal failure--case report]

Tubulointerstitial nephritis (TN) is a heterogenous disease, where disturbances of the interstitial tissue and renal tubules are found. Different immunological and nonimmunological mechanisms initiated by infectious and non-infectious factors may lead to TN. A case of 13-years-old girl with primary diagnosis of acute pyelonephritis is presented. The abdominal pain, headache, pain in lumbar region and intermittent fever with loss of appetite were observed in this girl a few weeks before admission. Microcytic anemia, proteinuria and glucosuria, azotemia and elevated markers of inflammatory response were found. In ultrasound examination heterogenous cortex echogenicity of both kidneys and disturbances in parenchymal blood flow were observed. In renal scintigraphy the discriminated catch index was found. Kidney biopsy revealed the edema of the interstitial space with mononuclear and lymphocyte infiltration. The diagnosis of TN was established upon the history, clinical examination, results of laboratory tests, kidney imaging and biopsy. After steroid and doxycycline treatment an improvement and normalization of the results of laboratory tests were observed. It seems to be justified to consider Yersinia infection as a cause of acute tubulointerstitial nephritis.

[Influence of vitamin E and N-acetylcysteine on intracellular oxidative stress in T lymphocytes in children treated with dialysis]

End-stage renal disease (ESRD) patients are subjected to enhanced oxidative stress. Excess of reactive oxygen species (ROS) may lead to the functional disabilities of lymphocytes. The aim of the study was to investigate the effect of vitamin E and N-acetylcysteine (NAC) on antioxidant status and intracellular oxidative stress in T-cells in children treated with dialysis.

MATERIAL AND METHODS

18 children treated with dialysis (hemodialysis n = 5 and peritoneal dialysis n = 13) were enrolled into the study. The age range was 2-20 ys. with a mean of 10.94 +/-5.86 ys. Vitamin E and NAC were given for six months orally. Throughout the study total antioxidant status (TAS), superoxide dismutase (SOD) and glutathione peroxidase (GPx) activity, and intracellular oxidative stress in T lymphocytes was measured.

RESULTS

In children treated with dialysis, TAS was significantly reduced compared to the controls (p = 0.012). We found no differences in GPx and SOD activities between patient and control groups. Mean fluorescence intensity (MFI), which reflected intracellular oxidative stress, was significantly increased in: CD3+, CD3+CD4- and CD8+CD28-. After six months of antioxidant treatment, a significant reduction in MFI was noted in most T-cell subsets (p < 0.001). MFI in T-helper cells remained unchanged. Although there was a trend toward rise in TAS and GPx activity, only significant differences in SOD activity were found (p = 0.022).

CONCLUSIONS

In children with ESRD treated with dialysis reduced TAS coexists with enhanced intracellular oxidative stress in T lymphocytes. The combined treatment with vitamin E and NAC lead to the reduction in oxidative stress within T-cells that might be of therapeutic value in dialyzed patients.

[Intracellular synthesis of cytokines as the index of function of peripheral blood lymphocytes and monocytes in children with first relapse of nephrotic syndrome]

BACKGROUND

Nephrotic Syndrome (NS) is a disease in which immune system function disorders play an important role. The aim of the study was an assessment of intracellular expression of cytokines in primary NS including assessment of intracellular expression of monokines (TNF-alpha, IL-8) in non-specific LPS stimulation system and intracellular expression of lymphokines (IL-2, INF-gamma, IL-4, IL-6) in experimental system with application of stimulation with ionomycin and PMA.

METHODS

The study included 47 children with NS aged 2-16 years. After activation of whole blood cells in the presence of brefeldin A the cells were labelled with monoclonal antibodies against surface antigens. In the second phase the cells underwent permeabilisation and were labelled with monoclonal antibodies against individual cytokines.

RESULTS

The studies performed demonstrated in children with NS relapse an increase of intracellular synthesis of cytokines characteristic of Th1 system (IL-2) and a decrease of synthesis of cytokines characteristic of Th2 system (IL-4, IL-6). In these patients an increase was also found of intracellular synthesis of proinflammatory monokines (TNF-alpha and IL-8). The studies performed, confirmed the earlier observations concerning abnormal cellular response in NS and demonstrated that differences in serum concentrations of individual cytokines may result from disturbances in their intracellular synthesis.

[Multiple bone fractures as a rare complication in a child with chronic renal failure]

Renal osteodystrophy may present with a wide spectrum of bone lesions, ranging from high bone turnover to low bone turnover. The authors present a case of multiple bone fracture in 12 year old boy with chronic renal failure. This boy was hospitalized because of retention of urea. The limping was observed by admision. In the X-rays of the long bones the multiple fracture were detected. The potential causes of these fractures and diagnostic problems were discussed.

Th1/Th2 balance and CD45-positive T cell subsets in primary nephrotic syndrome

T cells are involved in the pathogenesis of nephrotic syndrome (NS). The aim of the study was to determine whether the activity of T-helper-1 (Th1) and T-helper-2 (Th2) cells and the distribution of the lymphocyte subsets, namely CD45RA+CD4+ ("naive" helper T cells, suppressor-inducer), CD45RA+CD8+ ("naive" suppressor T cells, suppressor-effector), CD45RO+CD4+ ("memory" helper T cells), are predictive for steroid sensitivity in children with primary NS. These parameters were assessed at the onset of disease, before initiation of steroid therapy. Two groups of NS children were retrospectively formed according to steroid sensitivity (SS) or resistance (SR). The activity of Th1 and Th2 cells was defined by the production of interleukin-2 (IL-2), interferon-gamma, IL-4, and IL-10 in the supernatants of CD4+ T cell cultures activated with autologous monocytes presenting tetanus toxoid (TT). Peripheral lymphocyte subsets were determined using double- or triple-color flow cytometry. In SS children with NS we found a decreased proliferative response of CD4+ T cells to TT stimulation, cytokine synthesis indicating the predominance of Th2 activity, and an increased percentage of activated suppressor-inducer (CD45RA+ CD4+CD25+, 5.18+/-0.8, P<0.001) and suppressor-effector (CD45RA+CD8+CD25+, 2.05+/-0.6, P<0.01) cells, with the concomitant reduction of activated memory cells (CD45RO+CD4+CD25+, 0.2+/-0.1, P<0.001). In children with SRNS we found an increased proliferative response of CD4+ T cells to TT, a rise in activated memory (CD45RO+CD4+CD25+, 3.82+/-0.7, P<0.01) and suppressor-inducer peripheral T cells (CD45RA+ CD4+CD25+, 3.85+/-0.6, P<0.01), but a low percentage of activated suppressor-effector (CD45RA+CD8+ CD25+, 0.5+/-0.2, P<0.05) T cells. We conclude that prior to treatment the distribution of lymphocyte subpopulations in peripheral blood together with Th1 and Th2 cell activity provides a useful tool for evaluating the likelihood of steroid sensitivity in patients with primary NS.

[Resistance to therapy in primary nephrotic syndrome: effect of MDR1 gene activity]

MDR1 gene encodes for a transmembranous glycoprotein, gp-170, which acts as a drug export pump and is also a cyclosporine(CsA)-binding protein. This study aimed at evaluating MDR1 expression in NS sensitive(S) and resistant(R) to therapy (steroids/S/, cyclophosphamide/C/, CsA) patients. Twenty six boys, 13 girls aged 3-8 years were included to the study. MDR1 was analysed using: 1) evaluation of gp-170 activity according to DiC2/3/ [3,3-Diethyloxa-carbocyanine Iodide] by means of flow cytometry and as 2) mRNA expression of MDR1 determined by RT-PCR. The analysis was performed in the lymphocyte subset CD4/CD45RA presenting suppressor-inducer activity. Negative control, Jurkat-T-cell line, not expressing the MDR1 phenotype, was transfected with viral expression vector containing a full-length cDNA for the human MDR1 gene. We found that: in SR-NS the high expression of MDR1 was associated mainly with the suppressor-inducer T-cells (CD45RA+CD4+) and was subsequently enhanced during an ineffective treatment with C and/or CsA. C-R-NS and CsA-R-NS were partially reversible by S- and R-Verapamil; this was in vitro confirmed by inhibition of export pump activity, gp-170. SS-NS, C-S-NS and CsA-S-NS presented the low expression and activity of MDR1 comparing to R-children (p < 0.001) and healthy controls (p < 0.00001). Resistance to therapy in NS patients seems to be resulted from the enhanced expression of MDR1 gene and subsequent high activity of export pump P-gp-170. Calcium channel blockers may reverse the MRD1-related resistance in the therapy of NS. Analysis of MDR1 may help to detect of suspected therapy resistance in NS.

[Does the changed Th1/Th2 activity in children with the assessment of body water in children with nephrotic syndrome: initial results]

T cells are involved in the pathogenesis of nephrotic syndrome (NS). The aim of the study was to determine whether the activity of T-helper-1 (Th1) and T-helper-2 (Th2) cells are predictive for steroid sensitivity in children with primary NS. These parameters were assessed at the onset of disease, before initiation of steroid therapy. Two groups of NS children were retrospectively formed according to steroid sensitivity(SS) or resistance(SR). Activity of Th1 and Th2 cells was defined by the production of IL-2, IFN-gamma and IL-4, IL-10 (ELISA), respectively, in the supernatants of the culture of CD4+ T cell cultures activated with autologous monocytes presenting tetanus toxoid (TT). Peripheral lymphocyte subsets were determined using double or triple colour flow cytometry. In SS children with NS we found the cytokine synthesis indicating the predominance of Th2 activity. We conclude that prior to treatment the Th1 and Th2 cell activity provides a useful tool to evaluate the probability of steroid sensitivity in patients with primary NS.

Flow cytometric analysis of urine lymphocytes isolated from patients with renal transplants--purification of urine lymphocytes

Early diagnosis of rejection is a pivotal problem in renal transplantation. Recent advances in urinary cell analysis using flow cytometry are still burdened with difficulties concerning urine lymphocyte (UL) isolation. The analysis of lymphocytes washed out with the urine from the kidney transplant offers a tool to monitor noninvasively the intragraft immune response. However, the demand for optimal isolation of UL with high viability and good separation of other cell types has not, as yet, been met. The present study was undertaken to evaluate the optimal conditions for harvesting UL in order to perform adequate UL analysis by flow cytometry. We found that UL viability is mainly dependent on the time of urine harvesting. Low UL viability was caused by high urine osmolality due to high concentrations of urea and glucose. In contrast, high protein concentrations protected UL viability. Hence, the following algorithm of adequate UL isolation for flow cytometric analysis was established: (1) Collection of morning urine directly onto foetal calf serum (FCS: 30% v/v): (2) UL isolation within 2 h; (3) Erythrocyte lysis with subsequent two-step density gradient isolation of UL from residual erythrocytes, granulocytes (Ficoll-Isopaque, 1.077 g/cm3) and from uroepithelial cells (30% methylglucamine 3,5-diacetomido-2,4,6-triiodobenzoicum, 1.085 g/cmn3); (4) Flow cytometric analysis of UL using the 'live gate' setting in the area of blood lymphocyte cluster. Adequate UL isolation and special settings of the flow cytometer may provide a useful tool for early diagnosis and the noninvasive monitoring of renal transplant rejection.

Effect of Pseudomonas aeruginosa exotoxin A on CD3-induced human T-cell activation

The effect of Pseudomonas aeruginosa (PA) exotoxin A (P-ExA) on CD3-induced T-cell activation was studied on the level of T-cells (proliferation, synthesis of interleukin (IL)-2, expression of IL-2R complex, ICAM-1,2 and LFA-1 molecules), and on the level of monocytes (expression of ICAM-1,2, LFA-1 molecules, as well as FcRI and CD14 receptors). We found that: (1) P-ExA blocked T-cell proliferation and this effect was totally reversed by intact monocytes, and partially by IL-2 or TPA but not by costimulatory cytokines (IL-1alpha, IL-1beta, TNF-alpha or IL-6); (2) P-ExA transiently, in short-term cultures (48 h), inhibited synthesis of IL-2; (3) prolonged stimulation (96 h) of peripheral blood mononuclear cells (PBMC) or CD4 + T-cells with P-ExA in high or low doses (100 and 10 ng/ml, respectively), enhanced the level of IL-2 in the cultures; (4) P-ExA at low dose, combined with IL-1beta, TNF-alpha or IL-6, up-regulated synthesis of IL-2; and (5) stimulation of T-cells with anti-CD3 monoclonal antibody (mAb) and P-ExA at high dose diminished the expression of the p55 chain but not of the p75 chain of IL-2R complex and slightly affected the expression of CD3 complex, ICAM-1,2 and LFA-1 molecules. Hence, P-ExA can regulate the level of IL-2 in cultures of CD3-induced T-cells either by inhibition of IL-2 consumption (when P-ExA is applied in high dose), or by induction of IL-2 production (a costimulatory effect exerted by P-ExA in low dose in combination with monokines). Action of P-ExA on monocytes resulted in: (1) inhibition of the expression of ICAM-1,2 molecules and their ligand LFA-1 molecule; (2) low expression of FcRI receptor (a ligand for Fc part of CD3 mAb); and (3) inhibition (over 90%) of the expression of CD14 molecule. In conclusion, P-ExA-induced anergy of T-cells depends on: (a) decrease in the affinity of IL-2R complex on activated T-cells; and (b) inhibition of the accessory activities of monocytes.

[Reactivity to hepatitis B vaccination (HBV) in patients with uremia: association with defined HLA antigen configuration and complement protein allotypes C4A, C4B and B factor (Bf)]

Genes, which are responsible for the effectivity of immune response are located on the chromosome 6 similarly as the genes of the class I and II of the major histocompatibility complex (MHC) together with the genes of some complement proteins (C4A, C4B, B factor/Bf/). The study investigates the interdependence between HLA configuration as well as complement protein allotypes (C4A, C4B, Bf) with the reactivity to HBV vaccination of ESRD [end stage renal disease]-patients. 153 ESRD-patients (68 females, 85 males; mean duration of hemodialysis therapy 8.2 +/- 5.1 years) were studied. Subjects were vaccinated (Gen-H-B-Vax-D; Merck, Sharp and Dohme, 40 micrograms/dosis i.m.) in the schedule at 0, 1, 2, and 6 month. Non-responders (NR) were defined when the anti-HBs antibody titer was below 10 U/liter. HLA typing was performed by means of microlymphocytotoxicity assay, whereas complement allotypes were estimated by using high voltage gel electrophoresis with subsequent specific immunofixation with antibodies against C4A, C4B and Bf. In the non-responders group [NR = 34] a) the significantly higher occurrence of single HLA-A1 and/or HLA-B8 and/or Cw4 or DR3 or DR7 or DQ2 have been found. In about 40% of NR HLA-A1, -B8, -DR3, or -DQ2 antigens occurred as homozygotes.