A novel variant affecting the cytoplasmic tail of the FAT1 protocadherin causing coloboma and renal failure: A case report.

BACKGROUND: Variations in the protocadherin gene FAT1 have recently been associated with a syndrome that includes coloboma, facial dysmorphism, renal failure, syndactyly, and other developmental defects. MATERIALS AND METHODS: Detailed medical and family history, physical examination, and molecular analysis. RESULTS: This non-dysmorphic, intellectually normal 51-year-old woman presented with bilateral colobomata and renal failure of unclear etiology, and asymmetric sensorineural hearing loss. Family history was notable for multiple family members with various forms of cancer. Whole exome sequencing revealed a homozygous frame shift variant in FAT1, predicted to truncate the FAT1 protein at the furthest position in the protein structure published to date in a patient with coloboma. CONCLUSIONS: This case provides further evidence of the pleiotropic effects of FAT1 in optic fissure closure and kidney function. Also, because this variant is in the last exon, it would be anticipated to escape nonsense-mediated decay, opening the possibility that the protein is made and expressed, but not completely functional, as its intracellular domain is truncated.

Parathyroid Hormone Resistance and Autoantibodies to the PTH1 Receptor.

We describe two cases of acquired parathyroid hormone (PTH) resistance consequent to the development of serum PTH type 1 receptor (PTH1R) autoantibodies, which block PTH binding and signaling. Both cases were associated with other autoimmune manifestations, and one case was associated with atypical membranous glomerulonephritis. In vitro binding and signaling assays identified the presence of PTH1R-blocking IgG autoantibodies, which were not present in serum samples from patients with other renal or autoimmune disorders. (Funded by the Intramural Research Programs of the National Institute of Diabetes and Digestive and Kidney Diseases and others.).

Effects of Metreleptin on Proteinuria in Patients With Lipodystrophy.

CONTEXT: Patients with lipodystrophy have high prevalence of proteinuria. OBJECTIVE: To assess kidney disease in patients with generalized (GLD) vs partial lipodystrophy (PLD), and the effects of metreleptin on proteinuria in patients with lipodystrophy. DESIGN, SETTING, PATIENTS, INTERVENTION: Prospective, open-label studies of metreleptin treatment in patients with GLD and PLD at the National Institutes of Health. OUTCOME MEASURES: The 24-hour urinary albumin and protein excretion rates, estimated glomerular filtration rate (eGFR), and creatinine clearance (CrCl) were measured at baseline and during up to 24 months of metreleptin treatment. Patients with increases in medications affecting outcome measures were excluded. RESULTS: At baseline, patients with GLD had significantly greater albuminuria, proteinuria, eGFR, and CrCl compared with patients with PLD. CrCl was above the normal range in 69% of patients with GLD and 39% with PLD (P = 0.02). With up to 24 months of metreleptin treatment, there were significant reductions in albuminuria and proteinuria in patients with GLD, but not in those with PLD. No changes in eGFR or CrCl were observed in patients with GLD or PLD during metreleptin treatment. CONCLUSIONS: Patients with GLD had significantly greater proteinuria than those with PLD, which improved with metreleptin treatment. The mechanisms leading to proteinuria in lipodystrophy and improvements in proteinuria with metreleptin are not clear. Hyperfiltration was also more common in GLD vs PLD but did not change with metreleptin.

Safety and Tolerability of Omalizumab: A Randomized Clinical Trial of Humanized Anti-IgE Monoclonal Antibody in Systemic Lupus Erythematosus.

OBJECTIVE: Autoreactive IgE antibodies have been implicated in the pathogenesis of systemic lupus erythematosus (SLE). We hypothesize that omalizumab, a monoclonal antibody binding IgE, may improve SLE activity by reducing type I interferon (IFN) production by hampering plasmacytoid dendritic cells and basophil activation. This study was undertaken to assess the safety, tolerability, and clinical efficacy of omalizumab in mild to moderate SLE. METHODS: Sixteen subjects with SLE and a Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) score of ≥4 and elevated autoreactive IgE antibody levels were randomized to receive omalizumab or placebo (2:1) for 16 weeks, followed by 16 weeks of open-label treatment and a 4-week washout period. The SLEDAI-2K score, British Isles Lupus Assessment Group index (BILAG 2004) score, and physician's global assessment of disease activity were recorded at each visit. The type I IFN-induced gene signature was determined using quantitative polymerase chain reaction. RESULTS: Omalizumab was well tolerated with no allergic reactions, and mostly mild adverse events comparable to those experienced with placebo treatment. SLEDAI-2K scores improved in the omalizumab group compared to the placebo group at week 16 (P = 0.038), as well as during the open-label phase in subjects initially receiving placebo (P = 0.02). No worsening in BILAG scores or the physician's global assessment was detected. There was a trend toward a reduction in IFN gene signature in subjects treated with omalizumab (P = 0.11), especially in subjects with a high baseline IFN signature (P = 0.052). CONCLUSION: Our findings indicate that omalizumab is well tolerated in SLE and is associated with improvement in disease activity. Larger randomized clinical trials will be needed to assess the efficacy of omalizumab in patients with SLE.

Membranous nephropathy: Pilot study of a novel regimen combining cyclosporine and Rituximab.

INTRODUCTION: There is broad consensus that high grade basal proteinuria and failure to achieve remission of proteinuria are key determinants of adverse renal prognosis in patients with primary membranous nephropathy. Based on the fact that current regimens are not ideal due to short and long-term toxicity and propensity to relapse after treatment withdrawal, we developed a treatment protocol based on a novel combination of rituximab and cyclosporine which targets both the B and T cell limbs of the immune system. Herein, we report pilot study data on proteinuria, changes in autoantibody levels and renal function that offer a potentially effective new approach to treatment of severe membranous nephropathy. METHODS: Thirteen high-risk patients defined by sustained high-grade proteinuria (mean 10.8 g/d) received combination induction therapy with rituximab plus cyclosporine for 6 months, followed by a second cycle of rituximab and tapering of cyclosporine during an 18 month maintenance phase. RESULTS: Mean proteinuria decreased by 65% at 3 months and by 80% at 6 months. Combined complete or partial remission was achieved in 92% of patients by 9 months; 54% achieved complete remission at 12 months. Two patients relapsed during the trial. All patients with autoantibodies to PLA2R achieved antibody depletion. Renal function stabilized. The regimen was well tolerated. DISCUSSION: We report these encouraging preliminary results for their potential value to other investigators needing prospectively collected data to inform the design and power calculations of future randomized clinical trials. Such trials will be needed to formally compare this novel regimen to current therapies for membranous nephropathy.

miR-150 promotes renal fibrosis in lupus nephritis by downregulating SOCS1.

MicroRNAs (miRs) seem to mediate renal fibrosis in several renal diseases, with some miRs having profibrotic effects and others having opposing effects. Although differential expression of certain miRs has been described in lupus nephritis, it is unknown whether miRs contribute to fibrosis or could serve as biomarkers of specific histologic manifestations of lupus nephritis. Here, we compared miR expression in kidney biopsies from patients with lupus nephritis and identified miR-150 as the most differentially expressed miR in kidneys with high chronicity (chronicity index [CI] ≥ 4); miR-150 positively correlated with chronicity scores and the expression of profibrotic proteins. Overexpression of miR-150 significantly reduced expression of the antifibrotic protein suppressor of cytokine signaling 1 (SOCS1) and upregulated profibrotic proteins in both proximal tubular and mesangial cells. Directly targeting SOCS1 with a small interfering RNA produced similar results. Furthermore, TGF-ß1 induced miR-150 expression, decreased SOCS1, and increased profibrotic proteins in proximal tubular cells and podocytes; a miR-150 inhibitor reversed these changes, suggesting that the profibrotic effects of TGF-ß1 are, at least in part, mediated by miR-150. Consistent with these in vitro observations, biopsies with high miR-150 and high CI exhibited substantial expression of TGF-ß1, reduced SOCS1, and an increase in profibrotic proteins. In summary, miR-150 is a promising quantitative renal biomarker of kidney injury in lupus nephritis. Our results suggest that miR-150 promotes renal fibrosis by increasing profibrotic molecules through downregulation of SOCS1.

Microarray-based gene expression profiling in patients with cryopyrin-associated periodic syndromes defines a disease-related signature and IL-1-responsive transcripts.

OBJECTIVE: To analyse gene expression patterns and to define a specific gene expression signature in patients with the severe end of the spectrum of cryopyrin-associated periodic syndromes (CAPS). The molecular consequences of interleukin 1 inhibition were examined by comparing gene expression patterns in 16 CAPS patients before and after treatment with anakinra. METHODS: We collected peripheral blood mononuclear cells from 22 CAPS patients with active disease and from 14 healthy children. Transcripts that passed stringent filtering criteria (p values≤false discovery rate 1%) were considered as differentially expressed genes (DEG). A set of DEG was validated by quantitative reverse transcription PCR and functional studies with primary cells from CAPS patients and healthy controls. We used 17 CAPS and 66 non-CAPS patient samples to create a set of gene expression models that differentiates CAPS patients from controls and from patients with other autoinflammatory conditions. RESULTS: Many DEG include transcripts related to the regulation of innate and adaptive immune responses, oxidative stress, cell death, cell adhesion and motility. A set of gene expression-based models comprising the CAPS-specific gene expression signature correctly classified all 17 samples from an independent dataset. This classifier also correctly identified 15 of 16 post-anakinra CAPS samples despite the fact that these CAPS patients were in clinical remission. CONCLUSIONS: We identified a gene expression signature that clearly distinguished CAPS patients from controls. A number of DEG were in common with other systemic inflammatory diseases such as systemic onset juvenile idiopathic arthritis. The CAPS-specific gene expression classifiers also suggest incomplete suppression of inflammation at low doses of anakinra.

Tocilizumab in systemic lupus erythematosus: data on safety, preliminary efficacy, and impact on circulating plasma cells from an open-label phase I dosage-escalation study.

OBJECTIVE: To assess the safety of interleukin-6 receptor inhibition and to collect preliminary data on the clinical and immunologic efficacy of tocilizumab in patients with systemic lupus erythematosus (SLE). METHODS: In an open-label phase I dosage-escalation study, 16 patients with mild-to-moderate disease activity were assigned to receive 1 of 3 doses of tocilizumab given intravenously every other week for 12 weeks (total of 7 infusions): 2 mg/kg in 4 patients, 4 mg/kg in 6 patients, or 8 mg/kg in 6 patients. Patients were then monitored for an additional 8 weeks. RESULTS: The infusions were well tolerated. Tocilizumab treatment led to dosage-related decreases in the absolute neutrophil count, with a median decrease of 38% in the 4 mg/kg dosage group and 56% in the 8 mg/kg dosage group. Neutrophil counts returned to normal after cessation of treatment. One patient was withdrawn from the study because of neutropenia. Infections occurred in 11 patients; none was associated with neutropenia. Disease activity showed significant improvement, with a decrease of > or =4 points in the modified Safety of Estrogens in Lupus Erythematosus National Assessment version of the Systemic Lupus Erythematosus Disease Activity Index score in 8 of the 15 evaluable patients. Arthritis improved in all 7 patients who had arthritis at baseline and resolved in 4 of them. Levels of anti-double-stranded DNA antibodies decreased by a median of 47% in patients in the 4 mg/kg and 8 mg/kg dosage groups, with a 7.8% decrease in their IgG levels. These changes, together with a significant decrease in the frequency of circulating plasma cells, suggest a specific effect of tocilizumab on autoantibody-producing cells. CONCLUSION: Although neutropenia may limit the maximum dosage of tocilizumab in patients with SLE, the observed clinical and serologic responses are promising and warrant further studies to establish the optimal dosing regimen and efficacy.

Randomized, controlled trial of prednisone, cyclophosphamide, and cyclosporine in lupus membranous nephropathy.

Patients with lupus membranous nephropathy (LMN) are at substantial long-term risk for morbidity and mortality associated with protracted nephrotic syndrome, including ESRD. The optimal treatment for this condition is controversial. Forty-two patients with LMN participated in a randomized, controlled trial to compare adjunctive immunosuppressive drugs with prednisone alone. Adjunctive regimens included either cyclosporine (CsA) for 11 mo or alternate-month intravenous pulse cyclophosphamide (IVCY) for six doses; the control group received alternate-day prednisone alone. Median proteinuria was 5.4 g/d (range 2.7 to 15.4 g/d). We assessed the primary outcome, time to remission of proteinuria during the 12-mo protocol, by univariate survival analysis. At 1 yr, the cumulative probability of remission was 27% with prednisone, 60% with IVCY, and 83% with CsA. Although both IVCY and CsA were more effective than prednisone in inducing remissions of proteinuria, relapse of nephrotic syndrome occurred significantly more often after completion of CsA than after IVCY. By multivariate survival analysis, treatment with prednisone and high-grade proteinuria (>5 g/d) but not race or ethnicity were independently associated with a decreased probability of remission. Adverse effects during the 12-mo protocol included insulin-requiring diabetes (one with prednisone and two with CsA), pneumonia (one with prednisone and two with CsA), and localized herpes zoster (two with IVCY). In conclusion, regimens containing CsA or IVCY are each more effective than prednisone alone in inducing remission of proteinuria among patients with LMN.

Chronic granulomatous disease as a risk factor for autoimmune disease.

Chronic granulomatous disease (CGD) is characterized by recurrent infections and granuloma formation. In addition, we have observed a number of diverse autoimmune conditions in our CGD population, suggesting that patients with CGD are at an elevated risk for development of autoimmune disorders. In this report, we describe antiphospholipid syndrome, recurrent pericardial effusion, juvenile idiopathic arthritis, IgA nephropathy, cutaneous lupus erythematosus, and autoimmune pulmonary disease in the setting of CGD. The presence and type of autoimmune disease have important treatment implications for patients with CGD.

Systemic lupus international collaborating clinics renal activity/response exercise: comparison of agreement in rating renal response.

OBJECTIVE: To assess the degree to which physicians agree with each other and with ratings obtained with 3 existing responder indices, in rating the response to treatment of lupus nephritis. METHODS: Lupus nephritis patient medical records from 125 pairs of visits (6 months apart) were used to create renal response scenarios. Seven nephrologists and 22 rheumatologists rated each scenario as demonstrating complete response, partial response, same, or worsening. The plurality (most frequent) rating of renal response by the physicians was compared with the calculated score from the renal component of the British Isles Lupus Assessment Group (BILAG) index (original and updated [2004] version) and of the Responder Index for Lupus Erythematosus (RIFLE). The degree of agreement among the physicians was assessed by calculating intraclass correlation coefficients (ICCs). The degree of agreement between the plurality physician rating and ratings obtained with the established response indices was assessed using the kappa statistic. RESULTS: The ICC among all physicians was 0.64 (0.62 for nephrologists and 0.67 for rheumatologists). The chance-adjusted measure of agreement (kappa coefficient) between the plurality physician rating and the calculated score obtained using established indexes was 0.50 (95% confidence interval [95% CI] 0.38-0.61) for the RIFLE, 0.14 (95% CI 0.03-0.25) for the original BILAG, and 0.23 (95% CI 0.21-0.44) for the BILAG 2004. CONCLUSION: These findings indicate that rheumatologists as a group and nephrologists as a group have equal agreement in their rating of renal response. There was moderate agreement between plurality physician ratings and ratings obtained using the renal component of the RIFLE. Ratings of response using an index based on the original BILAG did not have good agreement with the plurality physician rating.

Systemic lupus international collaborating clinics renal activity/response exercise: development of a renal activity score and renal response index.

OBJECTIVE: To develop a measure of renal activity in systemic lupus erythematosus and use it to develop a renal response index. METHODS: Abstracted data from the medical records of 215 patients with lupus nephritis were sent to 8 nephrologists and 29 rheumatologists for rating. Seven nephrologists and 22 rheumatologists completed the ratings. Each physician rated each patient visit with respect to renal disease activity (none, mild, moderate, or severe). Using the most commonly selected rating for each patient as the gold standard, stepwise regression modeling was performed to identify the variables most related to renal disease activity, and these variables were then used to create an activity score. This activity score could then be applied to 2 consecutive visits to define a renal response index. RESULTS: The renal activity score was computed as follows: proteinuria 0.5-1 gm/day (3 points), proteinuria 0.5-1 gm/day = 3 points, proteinuria >1-3 gm/day = 5 points, proteinuria >3 gm/day = 11 points, [corrected] urine red blood cell count > = 5/hpf = 3 points, [corrected] urine white blood cell count > or = 5/hpf = 1 point. [corrected] The chance-adjusted agreement between the renal response index derived from the activity score applied to the paired visits and the plurality physician response rating was 0.69 (95% confidence interval 0.59-0.79). CONCLUSION: Ratings derived from this index for rating of renal response showed reasonable agreement with physician ratings in a pilot study. The index will require further refinement, testing, and validation. A data-driven approach to create renal activity and renal response indices will be useful in both clinical care and research settings.

Urinary exosomal transcription factors, a new class of biomarkers for renal disease.

Urinary exosomes are excreted from all nephron segments and constitute a rich source of intracellular kidney injury biomarkers. To study whether they contain transcription factors, we collected urine from two acute kidney injury models (cisplatin or ischemia-reperfusion), two podocyte injury models (puromycin-treated rats or podocin-Vpr transgenic mice) and from patients with focal segmental glomerulosclerosis, acute kidney injury and matched controls. Exosomes were isolated by differential centrifugation and found to contain activating transcription factor 3 (ATF3) and Wilms Tumor 1 (WT-1) proteins detected by Western blot. These factors were found in the concentrated exosomal fraction, but not in whole urine. ATF3 was continuously present in urine exosomes of the rat models following acute injury at times earlier than the increase in serum creatinine. ATF3 was found in exosomes isolated from patients with acute kidney injury but not from patients with chronic kidney disease or controls. Urinary WT-1 was present in animal models before significant glomerular sclerosis and in 9/10 patients with focal segmental glomerulosclerosis but not in 8 controls. Our findings suggest that transcription factor ATF3 may provide a novel renal tubular cell biomarker for acute kidney injury while WT-1 may detect early podocyte injury. Measurement of urinary exosomal transcription factors may offer insight into cellular regulatory pathways.

Triad of severe abdominal pain, inappropriate antidiuretic hormone secretion, and disseminated varicella-zoster virus infection preceding cutaneous manifestations after hematopoietic stem cell transplantation: utility of PCR for early recognition and therapy.

A hematopoietic stem cell transplant recipient developed abdominal pain, pneumatosis intestinalis, hepatitis, pancreatitis, and inappropriate antidiuretic hormone secretion. Blood for varicella-zoster virus (VZV) DNA polymerase chain reaction was positive. She was treated with acyclovir and subsequently developed VZV antigen-positive zoster. Detection of VZV DNA in blood may be useful for early diagnosis in immunocompromised hosts who present with zoster without skin lesions.

Spectrum of renal diseases associated with extreme forms of insulin resistance.

Diabetic nephropathy is the leading cause of ESRD in the United States. Why the pathogenic mechanisms lead to nephropathy in certain patients with type 1 and 2 diabetes and spare others is unclear, but it is clear that hyperglycemia and glomerular hyperfiltration are important factors. In patients with syndromes of extreme insulin resistance, proteinuric forms of renal disease are common, but it is surprising to find that the renal pathology usually is not diabetic nephropathy. For instance, in the lipodystrophy syndromes, membranoproliferative glomerulonephritis type 1 and type 2, focal segmental glomerulosclerosis, and also diabetic nephropathy are seen. In the syndromes of autoantibodies to the insulin receptor, the various forms of lupus glomerulonephritis are seen. Even in patients with type 2 diabetes, the renal pathology may not be diabetic nephropathy. Therefore, in patients with syndromic forms of insulin resistance and type 2 diabetes, renal biopsy has an important role in defining the pathology that leads to proteinuric nephropathy and in formulating a therapeutic approach. It is the purpose of this article to review these unusual aspects of proteinuric nephropathy in patients with diabetes.