Membranous nephropathy and primary biliary cholangitis: A case report and review of the literature.

AIM: Membranous nephropathy (MN) and primary biliary cholangitis (PBC) are autoimmune diseases that coexist in some cases and might share a common pathogenesis. In 75 - 80% of MN patients, PLA2R1 or THSD7A is the target antigen responsible for disease development, while in the remaining cases, MN pathogenesis is not clear. Our aim was to identify potential antigens playing an overlapping pathogenic role for development of both PBC and MN. MATERIALS AND METHODS: Serum from a patient with PBC-associated MN was analyzed for MN and PBC-specific autoantibodies and kidney biopsy tissue was stained for the respective antigens. A review of the literature for published PBC-associated MN cases was performed. RESULTS: A 39-year-old male patient was diagnosed with PBC-associated MN. Serology tests revealed negativity for PLA2R1-ab and THSD7A-ab, but positivity for two PBC-specific antibodies: M2-ab and gp210-ab. Kidney biopsy was stained for both PBC-specific antigens, PDC-E2 and gp210, as well as PLA2R1 and THSD7A, showing no MN-specific positivity. Human glomerular extracts also did not contain PDC-E2 or gp210. A review of all 17 published cases of PBC-associated MN showed that 71% of patients suffered from at least one additional autoimmune disease, and different IgG-subclasses were found in the renal immune deposits of these patients. CONCLUSION: These results indicate that both PBC-antigens are not the putative antigen(s) leading to MN development in this patient. PBC-antigens might not be directly responsible for MN development. Both diseases seem to present as autoimmune phenomena triggered by interaction between unknown factors.

Development and validation of a renal risk score in ANCA-associated glomerulonephritis.

Predicting renal outcome in antineutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis (GN) remains a major challenge. We aimed to identify reliable predictors of end-stage renal disease (ESRD) and to develop and validate a clinicopathologic score to predict renal outcome in ANCA-associated GN. In a prospective training cohort of 115 patients, the percentage of normal glomeruli (without scarring, crescents, or necrosis within the tuft) was the strongest independent predictor of death-censored ESRD. Regression tree analysis identified predictive cutoff values for three parameters: percentage normal glomeruli (N0 >25%, N1 10 to 25%, N2 <10%), percentage tubular atrophy and interstitial fibrosis (T0 ≤25%, T1 >25%), and estimated glomerular filtration rate at the time of diagnosis (G0 >15 ml/min/1.73 m2, G1 ≤15 ml/min/1.73 m2). Cox regression analysis was used to assign points to each parameter (N1 = 4, N2 = 6, T1 = 2, G1 = 3 points), and the resulting risk score was used to classify predicted ESRD risk as low (0), intermediate (2 to 7), or high (8 to 11 points). The risk score accurately predicted ESRD at 36 months in the training cohort (0%, 26%, and 68%, respectively) and in an independent validation cohort of 90 patients (0%, 27%, and 78%, respectively). Here, we propose a clinically applicable renal risk score for ANCA-associated GN that highlights the importance of unaffected glomeruli as a predictor of renal outcome and allows early risk prediction of ESRD.

Organisation of lymphocytic infiltrates in ANCA-associated glomerulonephritis.

AIMS: Renal involvement in anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis contributes to significant morbidity and mortality in patients. In chronic inflammation, B cells are recruited to the inflamed tissue and organised lymphoid structures have been described in several autoimmune diseases. The aim of this study was to correlate the lymphoid organisation in renal biopsies with renal outcome in ANCA-associated glomerulonephritis (GN). METHODS AND RESULTS: We investigated 112 renal biopsies from patients with newly diagnosed ANCA-associated necrotising GN. We identified four different levels of the intrarenal organisation of lymphocytes: T cells without B cells, scattered B and T cells, clustered lymphocytic infiltrates and nodular compartmentally arranged B and T cell aggregates. Almost half the patients showed clusters of B and T lymphocytes in their biopsies. In 15 of these biopsies, a higher degree of organisation with lymphocytic compartments was detected. Inflammatory cell organisation was associated with renal failure, but not with tubular atrophy and interstitial fibrosis. Patients with organised lymphocytic infiltrates in their biopsy had worse renal function during follow-up and were more likely to develop end stage renal disease. CONCLUSIONS: In the present study, we show that the renal lymphocytic organisation is associated with renal outcome in ANCA-associated GN. The organisation of the lymphocytic infiltrate may be a morphological correlate of a perpetual and exaggerated inflammation in renal ANCA disease. Classifying the lymphocytic infiltrate could help to predict renal outcome, and might therefore be used for individualised adjustments in the intensity and duration of immunosuppressive therapy.

Prevalence of ßIII-tubulin (TUBB3) expression in human normal tissues and cancers.

Microtubules are multifunctional cytoskeletal proteins that are involved in crucial cellular roles including maintenance of cell shape, intracellular transport, meiosis, and mitosis. Class III beta-tubulin (ßIII-tubulin, also known as TUBB3) is a microtubule protein, normally expressed in cells of neuronal origin. Its expression was also reported in various other tumor types, such as several types of lung cancer, ovarian cancer, and esophageal cancer. TUBB3 is of clinical relevance as overexpression has been linked to poor response to microtubule-targeting anti-cancer drugs such as taxanes. To systematically investigate the epidemiology of TUBB3 expression in normal and neoplastic tissues, we used tissue microarrays for analyzing the immunohistochemically detectable expression of TUBB3 in 3911 tissue samples from 100 different tumor categories and 76 different normal tissue types. At least 1 tumor with weak expression could be found in 93 of 100 (93%) different tumor types, and all these 93 entities also had at least 1 tumor with strong positivity. In normal tissues, a particularly strong expression was found in neurons of the brain, endothelium of blood vessels, fibroblasts, spermatogenic cells, stroma cells, endocrine cells, and acidophilic cells of the pituitary gland. In tumors, strong TUBB3 expression was most frequently found in various brain tumors (85%-100%), lung cancer (35%-80%), pancreatic adenocarcinoma (50%), renal cell carcinoma (15%-80%), and malignant melanoma (77%). In summary, these results identify a broad spectrum of cancers that can at least sporadically express TUBB3. Testing of TUBB3 in cancer types eligible for taxane-based therapies could be helpful to identify patients who might best benefit from this treatment.

CC Chemokine Ligand 18 in ANCA-Associated Crescentic GN.

ANCA-associated vasculitis is the most frequent cause of crescentic GN. To define new molecular and/or cellular biomarkers of this disease in the kidney, we performed microarray analyses of renal biopsy samples from patients with ANCA-associated crescentic GN. Expression profiles were correlated with clinical data in a prospective study of patients with renal ANCA disease. CC chemokine ligand 18 (CCL18), acting through CC chemokine receptor 8 (CCR8) on mononuclear cells, was identified as the most upregulated chemotactic cytokine in patients with newly diagnosed ANCA-associated crescentic GN. Macrophages and myeloid dendritic cells in the kidney were detected as CCL18-producing cells. The density of CCL18(+) cells correlated with crescent formation, interstitial inflammation, and impairment of renal function. CCL18 protein levels were higher in sera of patients with renal ANCA disease compared with those in sera of patients with other forms of crescentic GN. CCL18 serum levels were higher in patients who suffered from ANCA-associated renal relapses compared with those in patients who remained in remission. Using a murine model of crescentic GN, we explored the effects of the CCL18 murine functional analog CCL8 and its receptor CCR8 on kidney function and morphology. Compared with wild-type mice, Ccr8(-/-) mice had significantly less infiltration of pathogenic mononuclear phagocytes. Furthermore, Ccr8(-/-) mice maintained renal function better and had reduced renal tissue injury. In summary, our data indicate that CCL18 drives renal inflammation through CCR8-expressing cells and could serve as a biomarker for disease activity and renal relapse in ANCA-associated crescentic GN.

An integrated organoid omics map extends modeling potential of kidney disease.

Kidney organoids are a promising model to study kidney disease, but their use is constrained by limited knowledge of their functional protein expression profile. Here, we define the organoid proteome and transcriptome trajectories over culture duration and upon exposure to TNFα, a cytokine stressor. Older organoids increase deposition of extracellular matrix but decrease expression of glomerular proteins. Single cell transcriptome integration reveals that most proteome changes localize to podocytes, tubular and stromal cells. TNFα treatment of organoids results in 322 differentially expressed proteins, including cytokines and complement components. Transcript expression of these 322 proteins is significantly higher in individuals with poorer clinical outcomes in proteinuric kidney disease. Key TNFα-associated protein (C3 and VCAM1) expression is increased in both human tubular and organoid kidney cell populations, highlighting the potential for organoids to advance biomarker development. By integrating kidney organoid omic layers, incorporating a disease-relevant cytokine stressor and comparing with human data, we provide crucial evidence for the functional relevance of the kidney organoid model to human kidney disease.

Proof of Therapeutic Efficacy of a 177Lu-Labeled Neurotensin Receptor 1 Antagonist in a Colon Carcinoma Xenograft Model.

Increased expression of neurotensin receptor 1 (NTR1) has been shown in a large number of tumor entities such as pancreatic or colon carcinoma. Hence, this receptor is a promising target for diagnostic imaging and radioligand therapy. Using the favorable biodistribution data of the NTR1-targeting agent 111In-3BP-227, we investigated the therapeutic effect of its 177Lu-labeled analog on the tumor growth of NTR1-positive HT29 colon carcinoma xenografts. Methods: 3BP-227 was labeled with 177Lu. To assess its biodistribution properties, SPECT and CT scans of HT29-xenografted nude mice injected with 177Lu-3BP-227 were acquired, and ex vivo tissue activity was determined. To evaluate therapeutic efficacy, 2 groups of mice received the radiopharmaceutical in a median dose of either 165 MBq (129-232 MBq, n = 10) or 110 MBq (82-116 MBq, n = 10), whereas control mice were injected with vehicle (n = 10). Tumor sizes and body weights were monitored for up to 49 d. Renal function and histologic morphology were evaluated. Results: Whole-body SPECT/CT images allowed clear tumor visualization with low background activity and high tumor-to-kidney and -liver ratios. Ex vivo biodistribution data confirmed high and persistent uptake of 177Lu-3BP-227 in HT29 tumors (19.0 ± 3.6 vs. 2.7 ± 1.6 percentage injected dose per gram at 3 and 69 h after injection, respectively). The application of 177Lu-3BP-227 resulted in a distinct delay of tumor growth. Median tumor doubling time for controls was 5.5 d (interquartile range [IQR], 2.8-7.0), compared with 17.5 d (IQR, 5.5-22.5 d) for the 110-MBq and 41.0 d (IQR, 27.5-55.0) for the 165-MBg group. Compared with controls, median relative tumor volume at day 23 after injection was reduced by 55% (P = 0.034) in the 110-MBq and by 88% (P < 0.01) in the 165-MBq group. Renal histology and clinical chemistry results did not differ between radiotherapy groups and controls, suggesting absence of therapy-induced acute renal damage. Conclusion: These data demonstrate that the novel NTR1-targeting theranostic agent 3BP-227 is an effective and promising candidate for radioligand therapy, with a favorable preliminary safety profile and high potential for clinical translation.

Rat renal transplant model for mixed acute humoral and cellular rejection: Weak correlation of serum cytokines/chemokines with intragraft changes.

BACKGROUND: Acute renal allograft rejection remains a major cause of allograft dysfunction; especially for episodes with mixed humoral and cellular character which can be detrimental for graft survival. We established a rat RT model with exclusive and complete MHC-disparity to investigate pathomechanisms of acute rejection and evaluate serum multiplex assays as a diagnostic tool in this context. METHODS: LEW rats receive congeneic LEW.1W allografts (allo), no immunosuppression. Planned duration of the experiment was 4 weeks (n = 13 allo, n = 3 iso). To study kinetics of rejection, additional animals were sacrificed at day 7 (n = 6 allo and n = 3 iso) and day 21 (n = 3 allo). Serum cytokines and chemokine were longitudinally analyzed with multiplex assays in n = 5 allo and n = 5 controls. Allografts were assessed by histopathology, immunohisto-chemistry and PCR. RESULTS: Animals develop allograft dysfunction acute humoral rejection with additional cellular components. Donor-specific MHC-antibodies are already detectable at day seven (d7) after RT. Leukocytic graft infiltrates are dominated by macrophages and additionally consist of T-cells, B-cells and NK-cells. Increased intragraft expression of interleukin-2, interferon gamma, tumor necrosis factor alpha as well as B-cell activating factor and its receptor are observed. Of the 24 serum cytokines/chemokines, only CCL2 is significantly different (higher)in allo vs. controls at d7 (p = 0.02). CONCLUSIONS: Correlation of serum chemokines/cytokines with features of humoral and cellular rejection, as reproduced in our LEW.1W to LEW rat renal transplant model, is limited. Macrophages, B-cells and their signaling pathways deserve more attention in genesis and possibly also treatment of acute rejection.