Systemic lupus erythematosus

Systemic lupus erythematosus in children and adolescents is a multisystem autoimmune disease with a great variability in disease presentation and course. This article summarizes available epidemiologic data, clinical patterns, approaches to investigation and treatment, and recent outcome data.     

MSC-based therapies in solid organ transplantation

Immunomodulatory cell therapy as a complement to standard pharmacotherapy represents a novel approach to solid organ allograft acceptance. This methodology may allow for a reduced dose of immunosuppressive drug to be administered and thus attenuate the severe side effects associated with long-term immunosuppression such as drug-related impairment of renal function, increased risk from opportunistic infections and malignancies. Mesenchymal stem cells (MSCs) have been shown to possess both immune modulatory and regenerative properties in vitro and in preclinical models. Encouraging results have been reported from studies examining the safety and efficacy of MSCs as a treatment for acute graft-versus-host disease. MSCs represent a promising candidate cell therapy to supplement immunosuppression in recipients of solid organs, and initial reports on the clinical use of MSCs in kidney transplantation have been recently published (Tan et al. in J Am Med Assoc 307:1169–1177, 2012; Reinders et al. in Stem Cells Transl Med 2:107–111, 2013; Perico et al. in Transpl Int 26:867–878, 2013; Perico et al. in Clin J Am Soc Nephrol 6:412–422, 2011). An area of even greater interest might be the application of MSCs in clinical liver transplantation as graft survival is closely associated with overall patient survival. Here, we present preclinical findings and discuss their possible impact on clinical liver transplantation. Then we discuss clinical studies designed to investigate how MSCs may be distributed and act in solid organ transplantation.     

The New Histopathologic Classification of ANCA-Associated GN and Its Association with Renal Outcomes in Childhood

Background and objectives

A proposed histopathologic classification for ANCA-associated GN is predictive of long-term renal outcome in adult populations. This study sought to validate this system in a pediatric cohort.

Design, setting, participants, & measurements

This was a retrospective, single-center, cohort study of 40 children diagnosed and followed until their transition to adult care at one institution between 1987 and 2012. Renal biopsy specimens were reviewed by a pathologist blinded to patient outcome and were classified using the new histopathologic classification system of focal, crescentic, mixed, and sclerotic groups. Time to the composite outcome of CKD stages 3 and 4 (determined by eGFR with repeated creatinine measures using the Schwartz equation) or ESRD (defined as dialysis dependence or transplantation) were ascertained.

Results

The study population consisted of 40 children (70% female), followed for a median of 2.4 years. The biopsy specimens were categorized as focal in 13 patients (32.5%), crescentic in 20 (50%), mixed in two (5%), and sclerotic in five (12.5%). Mixed and crescentic were combined for analyses. Survival analysis of time to the composite renal endpoint of at least 3 months of eGFR<60 ml/min per 1.73 m² or ESRD differed significantly among the three biopsy groups log-rank P<0.001), with an adjusted hazard ratio of 3.14 (95% confidence interval, 0.68 to 14.4) in the crescentic/mixed group and 23.6 (95% confidence interval, 3.9 to 144.2) in the sclerotic category compared with the focal category. The probability of having an eGFR>60 ml/min per 1.73 m² at 2 years was 100% for the focal, 56.5% for the crescentic/mixed, and 0% for the sclerotic biopsy categories.

Conclusions

This study showed the clinical utility of this histopathologic classification system and its ability to discriminate renal outcomes among children with ANCA GN.     

Granulomatosis with Polyangiitis in Childhood

Granulomatosis with polyangiitis (GPA) is a rare yet frequently organ- or life-threatening systemic vasculitis affecting small- to medium-sized arteries in multiple organs. It characteristically leads to alveolar hemorrhage and destructive, pauci-immune glomerulonephritis. GPA is also characterized by granulomas in the upper and lower respiratory tract causing erosive sinusitis and nodular or even cavitating lesions in the respiratory tract. Antineutrophil cytoplasmic antibodies, a hallmark of GPA, are likely integral to the pathogenesis and recently have become a therapeutic target. International collaborations in childhood vasculitis have led to the development and validation of childhood vasculitis classification criteria, advanced our understanding of the clinical phenotype at presentation of GPA, and improved our ability to capture disease activity and determine treatment choices. Treatment efficacy and safety data continue to be largely derived from adult GPA studies. This review focuses on the recent publications on epidemiology, pathogenesis, and treatment in childhood GPA and relevant publications from the adult GPA literature.     

Marked changes of the hepatic sinusoid in a transgenic mouse model of acute immune-mediated hepatitis

BACKGROUND/AIMS: The liver sinusoidal endothelial cell (LSEC) is increasingly recognized as having an important role in hepatic immunity. However, the responses of LSECs and the hepatic sinusoid in immune-mediated hepatitis are poorly described. METHODS: We studied a transgenic mouse model of acute immune-mediated hepatitis: Met-Kb mice injected with T cells from Des-TCR mice. RESULTS: Hepatitis was characterized by lymphocyte infiltrates causing severe but transient liver damage. There were marked changes in the ultrastructure of the LSEC five days after injection of the T cells that coincided with the peak of the hepatitis. The porosity of fenestrations in the LSEC decreased and the endothelium became thickened. LSECs appeared to be markedly activated. These changes were associated with narrowing of the space of Disse, loss of hepatocellular microvilli and deposition of basal lamina. Lymphocytes were seen passing through fenestrations. Loss of fenestration in the LSEC prevented hepatitis induced by a second injection of lymphocytes on day 5. CONCLUSIONS: Structural changes in the LSEC occur during the peak of a mouse model of immune-mediated hepatitis. These changes were associated with attenuation of subsequent liver damage, suggesting that they may influence immunological responses mediated by LSECs or the passage of lymphocytes through LSEC fenestrations.