ALECT2 amyloidosis with concurrent IgG4-related interstitial nephritis, membranous nephropathy and diabetic kidney disease: a case report and literature review.

Leukocyte chemotactic factor-2 amyloidosis (ALECT2) is a recently described subtype of amyloidosis. IgG4-related disease is a rare fibroinflammatory condition characterized by dense interstitial lymphoplasmacytic infiltrates and fibrosis. Membranous nephropathy and diabetic nephropathy are common causes of nephrotic syndrome. Here we report a 49-year-old Hispanic male patient with diabetes mellitus who presented with jaundice and pruritus. IgG4-related autoimmune pancreatitis was diagnosed through laboratory workup and ampulla biopsy. He subsequently presented with marked lower extremity edema and nephrotic syndrome. Kidney biopsy showed severe interstitial IgG4-positive plasma cell-rich inflammatory infiltrates and interstitial storiform fibrosis. Immunofluorescence microscopy revealed diffuse and finely granular glomerular capillary wall staining for IgG and the glomeruli were negative for anti-phospholipase A2 receptor. Congo red stain was positive for birefringent deposits in the interstitium, arteriolar walls, and glomeruli. Electron microscopy demonstrated subepithelial immune complex-type electron-dense deposits, thickening of glomerular basement membranes (GBM), and randomly oriented fibrils in the mesangium, GBM, and interstitium. Mass spectrometry identified a peptide profile consistent with ALECT2 amyloidosis. This is the first report of a case with concurrence of ALECT2 amyloidosis, IgG4-related disease involving the kidney, membranous nephropathy, and early diabetic kidney injury.

Neuropathology and Ophthalmological Pathology of Fatal Central Nervous System Injuries in Young Children: Forensic Neuropathology of Deaths of Children Under Age 2, 2008-2016, in Central Missouri.

Nonaccidental head injuries are significant causes of morbidity and mortality among young children. Despite broad agreement among medical experts, controversies remain over diagnostic criteria, including from autopsies, because of opinions expressed by a small group of expert witnesses who testify for defendants in suspected child homicide cases. We reviewed 249 autopsies in children 2 years old and younger from the files of our Medical Examiner office in the University of Missouri School of Medicine done between January 1, 2008 and December, 31, 2016. Because of gradually instituted mandatory examination of spinal cords and retinas, we had 127 autopsies with brain examinations by a neuropathologist plus retinal examinations of which 67 also had spinal cord examinations. Results were correlated with clinical records, police and EMS reports, and imaging. We found that subdural hematomas, cerebral edema, and retinal hemorrhages were mostly limited to autopsy findings in children who suffered from fatal head trauma, whether accidental (3 cases) or inflicted (14); they were not encountered in cases of homicide by other mechanisms or from natural diseases including infections, brain tumors, SIDS/SUID, or SUDC. Two cases with no other evidence of head trauma had focal retinal hemorrhages. We advocate for examination of retinas and spinal cords in all autopsies of children in this age group.

Bartonella endocarditis and diffuse crescentic proliferative glomerulonephritis with a full-house pattern of immune complex deposition.

BACKGROUND: Bartonella endocarditis is often a diagnostic challenge due to its variable clinical manifestations, especially when it is first presented with involvement of organs other than skin and lymph nodes, such as the kidney. CASE PRESENTATION: This was a 13-year-old girl presenting with fever, chest and abdominal pain, acute kidney injury, nephrotic-range proteinuria and low complement levels. Her kidney biopsy showed diffuse crescentic proliferative glomerulonephritis with a full-house pattern of immune complex deposition shown by immunofluorescence, which was initially considered consistent with systemic lupus erythematous-associated glomerulonephritis (lupus nephritis). After extensive workup, Bartonella endocarditis was diagnosed. Antibiotic treatment and valvular replacement surgery were undertaken with subsequent return of kidney function to normal range. CONCLUSION: This case demonstrates the importance of considering the full clinical picture when interpreting clinical, laboratory and biopsy findings, because the treatment strategy for infective endocarditis versus lupus nephritis is drastically different.

Carcinosarcoma, a Rare Malignant Neoplasm of the Pancreas.

Carcinosarcoma of the pancreas is a rare entity with poor prognosis. Here, we report a case of pancreatic carcinosarcoma in a 68-year-old male patient who underwent a pancreatoduodenectomy for a unilocular cystic mass in the head of the pancreas. Histologically, the lesion showed a biphasic tumor with a carcinoma component and a spindle cell sarcomatous component, which were intimately intermingled. Most of the carcinoma components are well-differentiated ductal adenocarcinoma with small areas of moderately to poorly differentiated ductal adenocarcinoma. The sarcomatous component is a high-grade highly cellular spindle cell tumor with frequent mitosis and apoptosis. Immunohistochemical studies demonstrated that the carcinomatous component was positive for epithelial markers and cyclin D1, and the sarcomatous component was negative for these markers while positive for vimentin, p16, and DOG1 with patchy positivity for S100. Other markers, including SOX10, CD117, Melan A, HMB45, actin, desmin, myogenin, beta-catenin, TLE1, and p53, were negative in both components. Molecular studies demonstrated that the tumor was microsatellite stable. Whole exome next generation sequencing analysis was performed and no pathogenic alterations in the genes were identified.

Spectrum of Kidney Diseases in Patients With Hepatitis C Virus Infection.

OBJECTIVES: To study the pathologic spectrum of kidney diseases in patients with hepatitis C virus infection (HCV+). METHODS: Native kidney biopsy specimens in HCV+ patients were reviewed. RESULTS: A total of 9,836 native kidney biopsy specimens were evaluated from January 2007 to December 2016, of which 273 (2.8%) were from HCV+ patients, and of these, 115 (42.1%) had diagnoses consistent with HCV-associated glomerulonephritis (GN). Non-HCV-associated kidney diseases comprised most diagnoses (158 cases, 57.9%) including non-immune complex-mediated kidney diseases (127 cases, 46.5%) and other immune complex-mediated glomerular diseases (31 cases, 11.4%). Forty-one (40.6%) patients had HCV-associated GN among 101 HCV+ patients from 2007 to 2011 vs 74 (43.0%) patients with HCV-associated GN among 172 HCV+ patients from 2012 to 2016. HCV-associated GN showed five morphologic patterns: focal proliferative (5.2%), diffuse mesangial proliferative (50.4%), diffuse membranoproliferative (28.7%), proliferative GN with crescentic lesions (7.8%), and membranous patterns (7.8%). CONCLUSIONS: We found a spectrum of pathologic changes in renal biopsy specimens of HCV+ patients, with most having diseases unrelated to HCV infection, HCV-associated GN showing five morphologic patterns, and availability of effective HCV antiviral therapy not yet resulting in major changes in the spectrum of kidney diseases in these patients.

Anti-microRNA-21/221 and microRNA-199a transfected by ultrasound microbubbles induces the apoptosis of human hepatoma HepG2 cells.

Gene therapy, particularly microRNA (miRNA), is a promising candidate in the treatment of cancer; however, it is challenging to develop gene delivery systems. Ultrasound microbubbles have been used for gene delivery with excellent results. The present study aimed to investigate the transfection efficiency of HepG2 cells using ultrasound microbubbles. The effects of three miRNAs (miR-21, miR-221 and miR-199a) on HepG2 cells were also determined by performing ultrasound microbubble-mediated gene transfection. Three recombinant plasmids containing anti-miR-21, anti-miR-221 and miR-199a were fused with enhanced green fluorescent protein. For the transfection of genes, the type of contrast agent, the concentration of microbubble contrast agent and the exposure intensity of ultrasound were optimized. The expression of miRNAs was detected using reverse transcription-polymerase chain reaction. To determine the effect of anti-miR-21, anti-miR-221 and miR-199a on HepG2 cells, MTT, cell cycle analysis and Annexin V-PE/7-ADD apoptosis assays were performed. The optimal condition was 10% sulfur hexafluoride microbubbles at an ultrasound frequency of 2.0 MHz and mechanical index of 0.28. When cells were transfected with three recombinant plasmids using ultrasound microbubbles, there was significant downregulation of miR-21 and miR-221 and upregulation of miR-199a (P<0.05). All three treatments inhibited cell proliferation and promoted the apoptosis of cells. The present data indicated that the delivery of anti-miR-21, anti-miR-221 and miR-199a may be mediated by ultrasound microbubble contrast agents. With this approach, cell proliferation may be effectively inhibited and cell apoptosis may be induced. These are novel cancer therapy targets.

TPX2 as a prognostic indicator and potential therapeutic target in clear cell renal cell carcinoma.

OBJECTIVES: Our aims were to determine if targeting protein for Xklp2 (TPX2) is correlated with clear cell renal cell carcinoma (ccRCC) histology and oncologic outcomes using The Cancer Genome Atlas (TCGA) and an institutional tissue microarray (TMA). METHODS: Clinicopathological data obtained from the TCGA consisted of 415 samples diagnosed with ccRCC. A TMA was constructed from tumors of 207 patients who underwent radical nephrectomy for ccRCC. TPX2 expression by immunohistochemistry on TMA was assessed by a genitourinary pathologist. Clinical data were extracted and linked to TMA cores. TPX2 and Aurora-A mRNA coexpression were evaluated in the TCGA cohort. Overall survival (OS), cancer-specific survival, and recurrence-free survival (RFS) were analyzed using the Kaplan-Meier method and log-rank statistics. Univariate and multivariate analyses were conducted using Cox proportional hazard models. RESULTS: Median follow-up time for the TCGA cohort was 3.07 years. Aurora-A and TPX2 mRNA coexpression were significantly correlated (Pearson correlation = 0.918). High TPX2 mRNA expression was associated with advanced stage, metastasis, poor OS, and RFS. Median follow-up time for the TMA cohort was 5.3 years. Elevated TPX2 protein expression, defined as greater than 75th percentile staining intensity, was identified in 47/207 (22.7%) patients. Increased TPX2 immunostaining was associated with poor OS (P = 0.0327, 53% 5-year mortality), cancer-specific survival (P<0.01, 47.8% 5-year cancer-specific mortality), RFS (P = 0.0313, 73.6%, 5-year recurrence rate), grade, T stage, and metastasis. Multivariate analysis demonstrated elevated expression served as an independent predictor of RFS (hazard ratio = 3.62 (1.13-11.55), P = 0.029). CONCLUSIONS: We show TPX2, a regulator of Aurora-A, is associated with high grade and stage of ccRCC, and is an independent predictor of recurrence. Future studies are warranted testing its role in ccRCC biology, and its potential as a therapeutic target.

Development of systemic lupus erythematosus in NZM 2328 mice in the absence of any single BAFF receptor.

OBJECTIVE: To determine the necessity for any individual BAFF receptor in the development of systemic lupus erythematosus (SLE). METHODS: Bcma-, Taci-, and Br3-null mutations were introgressed into NZM 2328 mice. NZM.Bcma-/-, NZM.Taci-/-, and NZM.Br3-/- mice were evaluated for lymphocyte phenotype and BAFF receptor expression by flow cytometry; for B cell responsiveness to BAFF by in vitro culture; for serum levels of BAFF and total IgG and IgG anti-double-stranded DNA (anti-dsDNA) by enzyme-linked immunosorbent assay; for renal immunopathology by immunofluorescence and histopathology; and for clinical disease. RESULTS: BCMA, TACI, and B lymphocyte stimulator receptor 3 (BR3) were not surface-expressed in NZM.Bcma-/-, NZM.Taci-/-, and NZM.Br3-/- mice, respectively. Transitional and follicular B cells from NZM.Br3-/- mice were much less responsive to BAFF than were the corresponding cells from wild-type, NZM.Bcma-/-, or NZM.Taci-/- mice. In comparison with wild-type mice, NZM.Bcma-/- and NZM.Taci-/- mice harbored an increased number of spleen B cells, T cells, and plasma cells, whereas serum levels of total IgG and IgG anti-dsDNA were similar to those in wild-type mice. Despite their paucity of B cells, NZM.Br3-/- mice had an increased number of T cells, and the numbers of plasma cells and levels of IgG anti-dsDNA were similar to those in wild-type mice. Serum levels of BAFF were increased in NZM.Taci-/- and NZM.Br3-/- mice but were decreased in NZM.Bcma-/- mice. Despite their phenotypic differences, NZM.Bcma-/-, NZM.Taci-/-, and NZM.Br3-/- mice had renal immunopathology and clinical disease that were at least as severe as that in wild-type mice. CONCLUSION: Any single BAFF receptor, including BR3, is dispensable for the development of SLE in NZM mice. Development of disease in NZM.Br3-/- mice demonstrates that BAFF-BCMA and/or BAFF-TACI interactions contribute to SLE, and that a profound, life-long reduction in the numbers of B cells does not guarantee protection against SLE.

Dispensability of APRIL to the development of systemic lupus erythematosus in NZM 2328 mice.

OBJECTIVE: To determine the role of APRIL in the development of systemic lupus erythematosus (SLE) in mice. METHODS: Wild-type (WT) NZM 2328, NZM. April(-/-) , NZM.Baff(-/-) , and NZM.Baff(-/-) .April(-/-) mice were evaluated for lymphocyte phenotype by flow cytometry, for serum total IgG and IgG autoantibody levels by enzyme-linked immunosorbent assay, for glomerular deposition of IgG and C3 by immunofluorescence, for renal changes by histopathology, and for clinical disease by laboratory assessment (severe proteinuria). RESULTS: In comparison to WT mice, NZM.April(-/-) mice harbored increased spleen B cells, T cells, and plasma cells (PCs), increased serum levels of IgG antichromatin antibodies, and decreased numbers of bone marrow (BM) PCs. Glomerular deposition of IgG and C3 was similar in NZM.April(-/-) mice and WT mice, renal changes on histopathology tended to be more severe in NZM.April(-/-) mice than in WT mice, and development of clinical disease was identical in NZM.April(-/-) mice and WT mice. BM (but not spleen) PCs and serum IgG antichromatin and anti-double-stranded DNA antibody levels were lower in NZM.Baff(-/-) .April(-/-) mice than in NZM.Baff(-/-) mice, whereas renal immunopathology in each cohort was equally mild. CONCLUSION: APRIL is dispensable for the development of full-blown SLE in NZM mice. Moreover, the elimination of both APRIL and BAFF had no discernible effect on the development of renal immunopathology or clinical disease beyond that of elimination of BAFF alone. The reduction in BM PCs in hosts doubly deficient in APRIL and BAFF beyond that in hosts deficient only in BAFF raises concern that combined antagonism of APRIL and BAFF may lead to greater immunosuppression without a concomitant increase in therapeutic efficacy.

Macrophages are essential contributors to kidney injury in murine cryoglobulinemic membranoproliferative glomerulonephritis.

Mice transgenic for thymic stromal lymphopoietin (TSLP), under regulation of the lymphocyte-specific promoter Lck, develop cryoglobulinemia and membranoproliferative glomerulonephritis (MPGN) similar to the disease in patients. To determine whether infiltrating macrophages, a hallmark of this disease, are deleterious or beneficial in the injury process, we developed Lck-TSLP transgenic mice expressing the human diphtheria toxin receptor (DTR) under control of the monocyte/macrophage-restricted CD11b promoter (Lck-TSLP;CD11b-DTR). Treatment with DT resulted in a marked reduction of monocytes/macrophages in the peritoneal cavity of both CD11b-DTR and Lck-TSLP;CD11b-DTR mice and marked reduction of macrophage infiltration in glomeruli of Lck-TSLP;CD11b-DTR mice. Lck-TSLP;CD11b-DTR mice, with or without toxin treatment, had similar levels of cryoglobulinemia and glomerular immunoglobulin deposition as Lck-TSLP mice. Lck-TSLP;CD11b-DTR mice, treated with toxin, had reduced mesangial matrix expansion, glomerular collagen IV accumulation, expression of the activation marker α-smooth muscle actin and transforming growth factor-ß1 in mesangial cells, and proteinuria compared with control mice. Thus, macrophage ablation confers protection in this model and indicates a predominately deleterious role for macrophages in the progression of kidney injury in cryoglobulinemic MPGN.

B Cell and BAFF dependence of IFN-α-exaggerated disease in systemic lupus erythematosus-prone NZM 2328 mice.

IFN-α is a potent activator of innate and adaptive immunity, and its administration to preautoimmune (NZB×NZW)F1 mice promotes virulent systemic lupus erythematosus (SLE) disease. Given the known contributions of B cells and BAFF to SLE, we evaluated the ability of IFN-α administration to induce disease in wild-type (WT), B cell-deficient, and BAFF-deficient NZM 2328 mice. Whereas WT mice rapidly developed proliferative glomerulonephritis, marked proteinuria, and increased mortality in response to IFN-α administration, B cell-deficient mice developed neither renal pathology nor clinical disease. Moreover, BAFF-deficient mice, despite developing limited glomerular IgG and C3 deposition, also remained free of histological glomerulonephritis and clinical disease. Strikingly, similar T cell expansion and serum IgG responses were observed in adenovirus (Adv)-IFN-treated WT and BAFF-deficient mice despite their disparate pathological and clinical responses, whereas numbers of activated B cells increased in WT mice but not in BAFF-deficient mice. Nonetheless, B cell, plasma cell, and T cell infiltration of the kidneys in Adv-IFN-treated WT mice was similar to that in WT mice treated with Adv-control. Its ability to promote SLE disease in WT mice notwithstanding, IFN-α administration failed to drive the preferential expansion of CD4(+) memory T cells that occurs during the natural course of disease, and glomerular infiltration of macrophages failed to associate with development of disease. These results collectively suggest that therapeutic targeting in SLE of BAFF and/or B cells in SLE could be successful even in states of IFN-α overexpression. Moreover, our results document important biological differences between IFN-α-driven and spontaneous natural SLE disease.

Constitutive overexpression of BAFF in autoimmune-resistant mice drives only some aspects of systemic lupus erythematosus-like autoimmunity.

OBJECTIVE: To determine whether overexpression of BAFF can promote systemic lupus erythematosus (SLE)-like autoimmunity in mice that are otherwise autoimmune-resistant. METHODS: We used class II major histocompatibility complex (MHC)-deficient C57BL/6 (B6) mice as a model of resistance to SLE and Sles1-bearing B6 mice as a model of resistance to the autoantibody-promoting capacity of the Sle1 region. We generated BAFF-transgenic (Tg) counterparts to these respective mice and evaluated lymphocyte phenotype, serologic autoimmunity, renal immunopathology, and clinical disease in the BAFF-Tg and non-Tg mouse sets. RESULTS: Although constitutive BAFF overexpression did not lead to B cell expansion in class II MHC-deficient B6 mice, it did lead to increased serum IgG autoantibody levels. Nevertheless, renal immunopathology was limited, and clinical disease did not develop. In B6 and B6.Sle1 mice, constitutive BAFF overexpression led to increased numbers of B cells and CD4+ memory cells, as well as increased serum IgG and IgA autoantibody levels. Renal immunopathology was modestly greater in BAFF-Tg mice than in their non-Tg counterparts, but again, clinical disease did not develop. Introduction of the Sles1 region into B6.Sle1.Baff mice abrogated the BAFF-driven increase in CD4+ memory cells and the Sle1-driven, but not the BAFF-driven, increase in serum IgG antichromatin levels. Renal immunopathology was substantially ameliorated. CONCLUSION: Although constitutive BAFF overexpression in otherwise autoimmune-resistant mice led to humoral autoimmunity, meaningful renal immunopathology and clinical disease did not develop. This raises the possibility that BAFF overexpression, even when present, may not necessarily drive disease in some SLE patients. This may help explain the heterogeneity of the clinical response to BAFF antagonists in human SLE.

Increased plasma adiponectin closely associates with vascular endothelial dysfunction in type 2 diabetic patients with diabetic nephropathy.

Several studies found that adiponectin, an adipokine withstands atherosclerosis in vivo, is significantly increased in subjects with diabetic nephropathy (DN), but its clinical meaning remains unclear. For its structural similarity to complement C1q and collagen, we performed this study to explore the relationship between adiponectin and the vascular endothelial function alterations in DN patients. 50 type 2 diabetic patients without clinical cardiovascular complications were assigned to control group, microalbuminuria group (Micro-MA), and macroalbuminuria group (Macro-MA) according to the Mogensen's criteria. Plasma adiponectin and soluble vascular cell adhesion molecule-1 (sVCAM-1) were detected. Flow-mediated dilatation (FMD), nitroglycerin-induced dilatation (NID) and cardiologic parameters were measured by ultrasound cardiogram. Plasma adiponectin level was significantly and gradually increased in agreement with the amount of urine albumin excretion. sVCAM-1 was higher in Micro-MA and Macro-MA patients than in the controls, but it was comparable between the former 2 groups. FMD and NID were both remarkably decreased in Macro-MA group compared with Micro-MA and control group. For the whole subjects, plasma adiponectin was negatively related to FMD (r=-0.397, P<0.01) and NID (r=-0.413, P<0.01). These results suggest that increased plasma adiponectin may predict co-existing vascular endothelial dysfunction in DN patients.

Deletion of activating Fcgamma receptors does not confer protection in murine cryoglobulinemia-associated membranoproliferative glomerulonephritis.

Many types of glomerulonephritis are initiated by the deposition of immune complexes, which induce tissue injury via either engagement of Fc receptors on effector cells or via complement activation. Four murine Fcgamma receptors (FcgammaRs) have been identified at present. Ligand binding to FcgammaRI, III, and IV induces cell activation via the immunoreceptor tyrosine-based activation motif on the common gamma chain (FcRgamma). In this study, FcRgamma chain knockout (FcRgamma(-/-)) mice were crossed with thymic stromal lymphopoietin transgenic (TSLPtg) mice, which develop cryoglobulinemic membranoproliferative glomerulonephritis (MPGN). Female mice were studied at 30 and 50 days of age, when MPGN is in early and fully developed stages, respectively. Both TSLPtg and TSLPtg/FcRgamma(-/-) mice developed MPGN with massive glomerular immune deposits, mesangial cell proliferation, extensive mesangial matrix accumulation, and macrophage influx. TSLPtg/FcRgamma(-/-) mice had more glomerular immune complex deposits and higher levels of circulating cryoglobulins, IgG2a, IgG2b, and IgM, compared with TSLPtg mice. TSLPtg and TSLPtg/FcRgamma(-/-) mice developed similar levels of proteinuria. These results demonstrated that deletion of activating FcgammaRs does not confer protection in this model of immune complex-mediated MPGN. The findings contradict accepted paradigms on the role of activating FcgammaRs in promoting features of glomerulonephritis as seen in other model systems. We speculate engagement of FcgammaRs on cells such as monocytes/macrophages may be important for the clearance of deposited immune complexes and extracellular matrix proteins.

Imatinib suppresses cryoglobulinemia and secondary membranoproliferative glomerulonephritis.

Imatinib is a receptor tyrosine kinase inhibitor that blocks the activity of c-Abl, c-Kit, and PDGF receptors. We tested the protective effects of imatinib in thymic stromal lymphopoietin transgenic mice, a model of cryoglobulinemia and associated membranoproliferative glomerulonephritis (MPGN), in which some glomerular manifestations likely result from PDGF receptor activation. Surprising, administration of imatinib beginning at weaning suppressed production of cryoglobulin, attenuating both the renal injury and systemic features of cryoglobulinemia. Flow cytometry suggested that inhibition of B cell development in the bone marrow likely caused the reduction in cryoglobulin production. In addition, administration of imatinib to thymic stromal lymphopoietin transgenic mice with established MPGN also diminished cryoglobulin production and reversed the renal and systemic lesions. These data suggest that treatment with imatinib may be a novel therapeutic approach for cryoglobulinemia and MPGN in humans.

Renin-angiotensin system blockade is renoprotective in immune complex-mediated glomerulonephritis.

Blockade of the renin-angiotensin system is renoprotective in a variety of chronic nephropathies, but the direct effect of such treatment in active, immune complex-mediated glomerulonephritis is unknown. This study investigated the short- and long-term effects of an angiotensin-converting enzyme inhibitor (enalapril) and an angiotensin II type 1 receptor blocker (losartan) in thymic stromal lymphopoietin transgenic (TSLPtg) mice, which develop mixed cryoglobulinemia and severe cryoglobulinemia-associated membranoproliferative glomerulonephritis. Enalapril and losartan each reduced hypertension, proteinuria, glomerular extracellular matrix deposition, and mesangial cell activation in TSLPtg mice. These renoprotective effects were not observed with hydralazine treatment, despite a similar antihypertensive effect. Treatment with enalapril or losartan also decreased renal plasminogen activator inhibitor-1 in TSLPtg mice, assessed by immunohistochemistry and quantitative real-time reverse transcriptase-PCR. None of the treatments affected immune complex deposition or macrophage infiltration. Overall, enalapril- and losartan-treated TSLPtg mice survived significantly longer than untreated TSLPtg mice. These studies demonstrate that angiotensin blockade may provide renoprotective benefits, independent of its BP-lowering effect, in the treatment of active immune complex-mediated glomerulonephritis.

All-trans-retinoic acid aggravates cryoglobulin-associated membranoproliferative glomerulonephritis in mice.

BACKGROUND: Transgenic (tg) mice overexpressing thymic stromal lymphopoietin (TSLP) develop mixed cryoglobulinaemia with renal disease closely resembling human cryoglobulinaemic membranoproliferative glomerulonephritis (MPGN), as well as systemic inflammation involving lung, liver and skin as a result of cryoglobulin deposits. We assessed the effect of all-trans-retinoic acid (ATRA), a powerful anti-inflammatory agent, on this model of cryoglobulinaemic MPGN. METHODS: Groups of male TSLP tg mice and wild-type controls were treated with either ATRA (20 mg/kg) or vehicle 3 times weekly by intraperitoneal injection for 4 or 8 weeks, when mice were then sacrificed. Routine histology and immunohistochemistry for collagen IV, alpha-smooth muscle actin, Mac-2 and Ki67 were performed. Immunoglobulin levels were measured by enzyme-linked immunosorbent assay. RESULTS: ATRA unexpectedly exacerbated renal injury in TSLP tg mice with increased glomerular extracellular matrix, mesangial cell activation, glomerular cell proliferation, glomerular macrophage influx and immune complex deposition. Systemic injuries involving liver and lung, and the amount of circulating cryoglobulins were all worsened by ATRA treatment. Furthermore, ATRA resulted in increased IgG1 and IgM levels, the main components of the cryoglobulins in TSLP tg mice, and a manifestation of an enhanced Th2 immune response. CONCLUSIONS: ATRA is not protective but instead aggravates cryoglobulinaemic MPGN and its systemic manifestations in TSLP tg mice. We speculate these findings may be due to augmented production of pathogenic immunoglobulins and/or an enhanced systemic Th2 response. Although disappointing, our results also suggest caution in the application of retinoid therapy to human disease based on the largely positive animal data reported to date.

Phenotypic and genotypic features of Alport syndrome in Chinese children.

Chinese Alport syndrome (AS) was analyzed in 44 unrelated patients who were screened for mutations in the COL4A5 gene by polymerase chain reaction (PCR)-single-strand conformation polymorphism analysis or PCR direct sequencing in 30 of the 44 patients. The clinical data showed that all patients had hematuria; 25 of 29 male patients (86%) and 9 of 15 female patients (60%) had proteinuria; 11 of 29 male patients (38%) and 1 of 15 female patients (7%) had nephrotic-level proteinuria; 10 of 21 male patients examined (48%) and 1 of 12 female patients examined (8%) had hearing abnormalities. Renal function remained normal despite hearing abnormalities, and ocular lesions occurred in 10%. Among 30 of 44 patients who had a family history of end-stage renal disease (ESRD), 80% (24/30) belonged to X-linked juvenile kindreds, and 20% (6/30) patients to adult kindreds. Of the 44 patients, 14 did not have a family history of ESRD, while 11 of 14 patients diagnosed with X-linked AS did. DNA analysis revealed four missense mutations, two silent mutations, one substitution, and one in-frame deletion. PCR along with Southern hybridization analysis revealed a large deletion of the paired COL4A5 and COL4A6 genes. Chinese AS patients were characterized clinically with hematuria, heavy proteinuria, and more juvenile forms. Mutations in these patients were usually small mutations, while a large deletion involving the 5' part of both COL4A5 and COL4A6 genes was identified.