Advanced chronic kidney disease with life-threatening hypokalemia due to undiagnosed Gitelman syndrome.

We report a case of a 58-year-old woman presenting with symptoms of oliguria, fatigue, anorexia, constipation, hypovolemic signs, and laboratory tests showing severe hypokalemia (1.7 mEq/L), hyponatremia (120 mEq/L), high serum creatinine (SCr, 6.46 mg/dL) and urea (352 mg/dL). The patient had previously been diagnosed with chronic kidney disease (CKD), with SCr up to 2.58 mg/dL 1 year prior, and had in all her previous laboratory tests shown hypokalemia, which was treated with conservative measures and eplerenone despite low-normal blood pressure and normal heart function. A set of coordinated measures were applied to restore the potassium deficit, revert hypovolemic hyponatremia, and support renal function (including 4 dialysis sessions). In addition, a careful diagnostic approach revealed inappropriately high urine sodium and potassium losses, hypocalciuria, and hyperreninemic hyperaldosteronism leading to the diagnosis of Gitelman syndrome and hypokalemia-associated chronic tubulointerstitial nephropathy. Importantly, compliance with a simple set of instructions on high potassium and liberal sodium diet enabled the patient not only to remain euvolemic, free of symptoms, and with normal electrolytes, but also to recover a significant part of renal function and stabilize at an earlier CKD stage. Gitelman syndrome is a rare disorder that can be easily diagnosed and treated following simple measures; its early diagnosis is necessary to avoid life-threatening complications.

End stage renal disease has an early and continuous detrimental effect on regulatory T cells.

End stage renal disease (ESRD) is followed by disturbed adaptive immunity, together with alterations in T cell subsets, including CD4+CD25+FoxP3+ cells (Tregs). In the present study, we assessed the effect of haemodialysis (HD) on the Treg population. CD3+CD4+, CD3+CD8+ and CD4+CD25+FoxP3+ cells were estimated by flow cytometry in 142 ESRD patients (45 ESRD-preHD, 97 on HD) and 30 healthy controls (HC). Patients on HD were classified into three groups according to time on dialysis (HD vintage - HDV): A < 2 years, B: 2-5 years and C: >5 years on HD. The mean age of patients on HD (M/F 53/44) was 54.8 ± 14 years and the median HDV 58 (78) months. We observed a significant progressive reduction in the percentage and count of lymphocytes (p < .001, p < .001, respectively), CD3+CD4+ (p = .003 and, p < .001, respectively) and Tregs (p = .001 and, p < .001, respectively), between HC, ESRD-preHD and HD patients. HDV had a significant inverse correlation with total lymphocyte, CD3+CD4+ and Treg cell counts (p = .001, p < .001, p < .001, respectively) and, the percentage of lymphocytes and CD3+CD4+ cells (p = .005, p = .01, respectively). Furthermore, we stratified patients on HD into three groups according to HDV: A < 2 years, B: 2-5 years and C: >5 years on HD. Total lymphocytes and Tregs were significantly different among the three vintage groups (Kruskal-Wallis H test, p < .001, p < .001 respectively). CD3+CD4+ and CD3+CD8+ cells were also significantly affected (p < .001 and p = .001, respectively), after at least 2 years of HD. Tregs show prompt and significant reduction at the pre-dialysis stage, and continue to decrease gradually even after long-term HD, in a context of total lymphocyte reduction.

Histology and Immunohistochemistry of Radial Arteries Are Suggestive of an Interaction between Calcification and Early Atherosclerotic Lesions in Chronic Kidney Disease.

Background and Objectives: recent studies suggest an implication of immune mechanisms in atherosclerotic disease. In this paper, the interaction between inflammation, calcification, and atherosclerosis on the vessel walls of patients with chronic kidney disease (CKD) is described and evaluated. Materials and Methods: patients with stage V CKD, either on pre-dialysis (group A) or on hemodialysis (HD) for at least 2 years (group B), in whom a radiocephalic arteriovenous fistula (RCAVF) was created, were included in the study. The control group included healthy volunteers who received radial artery surgery after an accident. The expressions of inflammatory cells, myofibroblasts, and vascular calcification regulators on the vascular wall were estimated, and, moreover, morphometric analysis was performed. Results: the expressions of CD68(+) cells, matrix carboxyglutamic acid proteins (MGPs), the receptor activator of nuclear factor-kB (RANK) and RANK ligand (RANKL), and osteoprotegerin (OPG), were significantly increased in CKD patients compared to the controls p = 0.02; p = 0.006; p = 0.01; and p = 0.006, respectively. In morphometric analysis, the I/M and L/I ratios had significant differences between CKD patients and the controls 0.3534 ± 0.20 vs. 0.1520 ± 0.865, p = 0.003, and 2.1709 ± 1.568 vs. 4.9958 ± 3.2975, p = 0.03, respectively. The independent variables correlated with the degree of vascular calcification were the intensity of CD34(+), aSMA(+) cells, and OPG, R2 = 0.76, p < 0.0001, and, with intima-media thickness (IMT), the severity of RANKL expression R2 = 0.3, p < 0.0001. Conclusion: atherosclerosis and vascular calcification in CKD seem to be strongly regulated by an immunological and inflammatory activation on the vascular wall.

Serum Levels of miR-148b and Let-7b at Diagnosis May Have Important Impact in the Response to Treatment and Long-Term Outcome in IgA Nephropathy.

BACKGROUND/AIMS: Previous studies showed that two microRNAs, let-7b and miR-148, which regulate the O-glycosylation process of IgA1, may predict diagnosis of primary IgA nephropathy (IgAN). The combined analysis of their serum levels in calculated statistical models may act as serum biomarkers for the diagnosis of primary IgAN. In the present study, we aimed to assess their impact not only on clinical and histological findings at onset but also on renal function after a long-term follow-up. PATIENTS AND METHODS: We enrolled 61 Caucasian patients with biopsy-proven IgAN. Serum levels of miR-148b, let-7b, and galactose-deficient IgA1 (Gd-IgA1) at the time of diagnosis were measured using real-time quantitative PCR and enzyme-linked immunosorbent assay using the monoclonal antibody KM55, respectively. Their values along with calculated Models 1 and 2 were correlated with histologic scoring system (Oxford classification system) and with renal function at diagnosis and after 11.9 ± 6.6 years. Fifty-five healthy volunteers were enrolled as controls. RESULTS: No significant correlation was found between miRNA and Gd-IgA1 levels and eGFR and proteinuria at diagnosis. A significant negative association was detected between the presence of crescents and serum levels of let-7b (p = 0.002), miR-148b (p = 0.01), and Models 1 and 2 (p = 0.02 and p = 0.007, respectively). At the end of follow-up, eGFR correlated with let-7b levels (p = 0.01), Model 1 (p = 0.002), and Model 2 (p = 0.004). Patients with fast progression of the renal damage had significantly increased levels of let-7b (p = 0.01), Model 1 (p = 0.003), and Model 2 (p = 0.005) compared to slow progressors, as did those who reached ESKD (p = 0.002, p = 0.001, and p = 0.001, respectively). Results were most prominent in those treated with corticosteroids. Finally, cut off levels in Models 1 and 2 could also predict the renal function outcome after long-term follow-up. CONCLUSIONS: Serum levels of let-7b and miR-148b and their combination, may serve as predictors for long-term renal function outcomes, particularly in patients treated with corticosteroids.

CD28null and Regulatory T Cells Are Substantially Disrupted in Patients with End-Stage Renal Disease Due to Diabetes Mellitus.

BACKGROUND: End-stage renal disease (ESRD) is associated with alterations in T-cell immunity, including increased CD28null and reduced regulatory T cells (Tregs). However, whether immune disturbances are due to ESRD or primary disease is not yet clear. As diabetes mellitus is the leading cause of ESRD, we evaluated its impact on the immune profile of ESRD patients. METHODS: CD28null, Tregs, and natural killer cells were initially analyzed by flow cytometry in 30 predialysis ESRD patients due to diabetes (DM), 30 non-DM (NDM), and 25 healthy controls. Measurements were repeated after 6 months on hemodialysis (HD) or peritoneal dialysis (CAPD). RESULTS: The percentage of CD4 + CD28null cells, CD8 + CD28null cells, and Tregs showed significant differences in DM, NDM, and controls; mean rank 33.71 vs. 25.68 vs. 18.88, p = 0.006, 37.79 vs. 28.82 vs. 17.08, p = 0.008, and 20.79 vs. 26.12 vs. 41.33, p = 0.001, respectively. DM vs. NDM had increased CD4 + CD28null and CD8 + CD28null cells, 11.5% (1.5%-24%) vs. 4.1% (0-42.3%), p = 0.02 and 61.3% (24%-76%) vs. 43% (5.7%-85%), p = 0.04, respectively. After 6 months on HD but not CAPD, DM showed a significant further increase in CD4 + CD28null cells, from 30 (14-100) to 52.7 (15-203), p = 0.02; and CD8 + CD28null cells, from 137 (56-275) to 266 (103-456), p = 0.01. CONCLUSIONS: Diabetes mellitus affects T-cell subtypes even at predialysis stage, though changes become more prominent after commencement on HD.

Influence of end stage renal disease on CD28 expression and T-cell immunity.

BACKGROUND: T-cell immunity is affected in end stage renal disease (ESRD). However, whether this happens at pre- or post-dialysis stage and what is the impact of different renal replacement methods, remains unclear. We investigated the alterations of T-cell subtypes in patients at pre-dialysis ESRD and their further changes during dialysis. METHODS: CD4+, CD8+, CD4 + CD28null and CD8 + CD28null T-cells were analysed in 40 ESRD patients at two different time points, (a) the day started on dialysis (ESRD-T0) and (b) 6 months later (ESRD-T6), while being on haemodialysis (HD) or continuous ambulatory peritoneal dialysis (CAPD). Twenty-five age matched healthy volunteers served as controls. RESULTS: CD4+ and CD8+ T-cells were significantly reduced in ESRD-T0 patients compared to controls, 604 (105-3551) vs 943 (584-1867)µ/L, P = .001, and 352 (103-1561) vs 422.4 (263-1453)µ/L, P = .05, respectively. However, proportions of CD4 + CD28null and CD8 + CD28null cells were significantly increased, 6.4 (0.3-30)% vs 2.7 (0.1-7.8)%, P = .04 and 58.2 (12.8-85.4)% vs 39 (7.8-57.1)%, P = .01, respectively. Proportion of CD4 + CD28null cells showed significant correlation with serum CRP (r = .4, P = .04) and albumin levels (r = -.5, P = .007) in ERSD patients. ESRD-T0 patients with cardiovascular disease (CVD) had increased CD4 + CD28null and CD8 + CD28null proportions, 8.6 (1-30)% vs 2.1 (0.1-19.8)%, P = .04 and 62.5 (12.8-85.4)% vs 45.5 (5.7-73.7)%, P = .02, respectively, compared to those without. Six months later, both CD4 + CD28null and CD8 + CD28null T-cells were increased in HD compared to CAPD patients, by +110.11 (-27.1 to 311.4)% vs -28.1 (-100 to 30)%, P = .003 and +55.23 (-29.06 to 197.93)% vs -8.34 (-54.99 to 66.72)%, P = .05, respectively. CONCLUSIONS: CD4 + CD28null and CD8 + CD28null T-cells are increased at pre-dialysis ESRD, and correlate with chronic inflammatory markers and the presence of CVD. Dialysis methods seem to have different impact on these subpopulations.

Different Types of ANCA Determine Different Clinical Phenotypes and Outcome in ANCA-Associated Vasculitis (AAV).

AIM: Accumulating evidence supports the use of antineutrophil cytoplasmic antibody (ANCA) type to classify different clinical entities. We aimed to evaluate whether the presence and type of ANCA determine different diseases, based on clinical phenotypes, renal involvement, and response to treatment. PATIENTS AND METHODS: Differences in terms of clinical manifestations, disease activity, laboratory parameters, and histology were recorded between patients with focal necrotizing glomerulonephritis (FNGN) due to myeloperoxidase (MPO-), proteinase 3-ANCA(+) [PR3-ANCA(+)], and ANCA(-) disease at time of diagnosis. Patients were treated with the same protocol and followed-up for 24 months, in a scheduled basis of every month for the first year and every 3 months for the second year. Primary end points were: (i) Combined end-stage renal disease (ESRD) and/or death and (ii) The presence of major or minor relapse during follow-up and secondary endpoint was the combination of ESRD and reduction of estimated glomerular filtration rate (eGFR) ≥ 50%. RESULTS: A total of 92 patients (M/F 39/53, mean age 59.1 ± 15 years) diagnosed with FNGN due to ANCA-associated vasculitis (AAV), 36 (39.1%) patients diagnosed with PR3-ANCA, 39 (42.4%) patients diagnosed with MPO-ANCA, and 17 (18.5%) patients diagnosed with ANCA(-) were included. Number of involved systems differed significantly between PR3-, MPO-ANCA, and ANCA(-), with only renal involvement in 3, 25.5, and 29% of patients, two systems involved in 33, 31, and 59% of patients, and > 3 systems involved in 64, 43.5, and 12% of patients, respectively (p = 0.002). Histology classification revealed focal, crescentic, mixed, and sclerotic type in 14, 64, 19, and 3% of PR3-ANCA(+), 8, 28, 18, and 46% of MPO-ANCA, and 41, 29, 6, and 24% of ANCA(-), respectively (p < 0.0001). Primary end point of ESRD ± Death was reached in 11 (30.6%), 16 (41%), and 6 (35.5%) patients with PR3-ANCA(+), MPO-ANCA(+), and ANCA(-), respectively (p = NS); similarly, ESRD± > 50% eGFR reduction in 8 (22.2%), 15 (38.5%), and 5 (29.4%) patients, respectively (p = NS), meaning that patients with MPO-ANCA(+) showed a propensity to decline renal function. Rate of relapse was increased in the presence of patients with PR3-ANCA(+), 14 (38.9%), 4 (11.8%), and 2 (10.3%) of patients with PR3-ANCA(+), MPO-ANCA(+), and ANCA(-), had at least one relapse during the two-year follow-up (p = 0.006). CONCLUSION: Clinical phenotype and renal histology differ significantly between PR3-ANCA(+), MPO-ANCA(+), and ANCA(-) disease and FNGN; however, renal function outcome is similar, despite the increased rate of relapses in patients with PR3-ANCA(+).

Systemic complement activation in anti-neutrophil cytoplasmic antibody-associated vasculitis and necrotizing glomerulonephritis.

AIM: Due to the accumulating evidence of complement activation in anti-neutrophil cytoplasmic antibody (ANCA) associated vasculitis (AAV), we decided to investigate the possibility of systemic complement activation in patients with Necrotizing Glomerulonephritis secondary to AAV. METHODS: Clinical, laboratory and histological findings, and serum levels of complement components, C3a, C5a and Bb fragment of Factor B and C4d, were estimated in patients with AAV and glomerulonephritis, at time of diagnosis, before any treatment had been applied. All patients were treated with the same immunosuppressive protocol and followed up for total 24 months. Twenty age and sex matched healthy individuals served as controls. RESULTS: Serum levels of all complement components were significantly increased in patients, compared to controls; C5a: 19.9(0.02-48) vs 9.06(2.1-16.3)pg/mL, P = .002, Bb: 7.3(0.02-31.4) vs 0.2(0.02-1.6)pg/mL, P < .0001, C3a: 4.7(0.4-7.2) vs 2.4(1.09-5)pg/mL, P = .05 and C4d: 11.6(0.07-70) vs 0.7(0.07-8.2)pg/mL, P = .001, respectively. There was strong correlation between serum Bb levels and eGFR and FFS2009 score at time of diagnosis (r = -.41, P = .002 and r = .41, P = .003 respectively). Also, serum Bb levels were increased in patients with severe interstitial infiltration (P = .04) and focal necrosis (P = .01) on renal biopsy. Serum Bb levels could also predict renal function outcome during the acute phase of disease, but not at the end of follow up. CONCLUSION: We provided strong evidence of systemic activation of complement alternative pathway in the development and progression of AAV and glomerulonephritis. Serum Bb seem to play a critical role in the induction, also predicting disease activity and outcome, yet activation of classical pathway cannot be excluded.