Uncharted waters: mesenchymal stem cell treatment for pediatric refractory rheumatic diseases; a single center case series.

BACKGROUND: With the advent of innovative therapies including biologics and Janus kinase inhibitors, children with rheumatic diseases are more likely to have improved outcomes. Despite these advances, some children do not respond, or they, or their parents fear adverse events and seek other alternatives. Increasingly, private companies are offering mesenchymal stem cells (MSC) as an alternative, which are described as natural therapies for rheumatic diseases, often insinuating them as a cure. MSC have immunomodulatory properties, and transplantation of these stem cells have been used to successfully treat immunologic conditions like graft-versus-host disease. Lately, MSC research in adult lupus has been encouraging, but the clinical trials are still underway and in most, MSC therapy is not a standalone treatment. This retrospective case series will highlight three cases of pediatric refractory autoimmune disease whose parents sought out and received MSC therapy as a self-decision without first seeking medical advice from our specialty. The three families felt that their children were improved and in two believed that their child was cured. MSC have the potential of beneficial immunomodulation and may be a powerful tool in the therapy of rheumatic disease, but well controlled clinical trials are necessary and should be designed and monitored by experts in childhood rheumatic disease. CASE PRESENTATION: Three children with three different rheumatic diseases; systemic lupus erythematosus, mixed connective tissue disease and juvenile idiopathic arthritis were under the care of pediatric rheumatology at a large, tertiary-care, teaching institution. Multiple non-biologic and biologic disease-modifying anti-rheumatic drugs failed to significantly decrease disease activity, and as a result, the families chose to undergo MSC therapy. After transplantation, all children improved per patient and parent report and tapered off conventional immunosuppressive drugs. No serious adverse events occurred in these three patients. CONCLUSION: The three cases presented in this report reflect comparable beneficial outcomes and minimal risks published in adult studies. These were not controlled studies, however, and benefit was reported rather than documented. These cases suggest that MSC transplantation may prove a promising adjunctive treatment option; however, further research, development of standardized infusion therapy protocols, and well-designed monitored clinical trials are essential.

Plasma levels of osteopontin identify patients at risk for organ damage in systemic lupus erythematosus.

INTRODUCTION: Osteopontin (OPN) has been implicated as a mediator of Th17 regulation via type I interferon (IFN) receptor signaling and in macrophage activity at sites of tissue repair. This study assessed whether increased circulating plasma OPN (cOPN) precedes development of organ damage in pediatric systemic lupus erythematosus (pSLE) and compared it to circulating plasma neutrophil gelatinase-associated lipocalin (cNGAL), a predictor of increased SLE disease activity. METHODS: cOPN and cNGAL were measured in prospectively followed pSLE (n=42) and adult SLE (aSLE; n=23) patients and age-matched controls. Time-adjusted cumulative disease activity and disease damage were respectively assessed using adjusted-mean SLE disease activity index (SLEDAI) (AMS) and SLICC/ACR damage index (SDI). RESULTS: Compared to controls, elevated cOPN and cNGAL were observed in pSLE and aSLE. cNGAL preceded worsening SLEDAI by 3-6 months (P=0.04), but was not associated with increased 6-month AMS. High baseline cOPN, which was associated with high IFNalpha activity and expression of autoantibodies to nucleic acids, positively correlated with 6-month AMS (r=0.51 and 0.52, P=0.001 and 0.01 in pSLE and aSLE, respectively) and was associated with SDI increase at 12 months in pSLE (P=0.001). Risk factors for change in SDI in pSLE were cOPN (OR 7.5, 95% CI [2.9-20], P=0.03), but not cNGAL, cumulative prednisone, disease duration, immunosuppression use, gender or ancestry using univariate and multivariate logistic regression. The area under the curve (AUC) when generating the receiver-operating characteristic (ROC) of baseline cOPN sensitivity and specificity for the indication of SLE patients with an increase of SDI over a 12 month period is 0.543 (95% CI 0.347-0.738; positive predictive value 95% and negative predictive value 38%). CONCLUSION: High circulating OPN levels preceded increased cumulative disease activity and organ damage in SLE patients, especially in pSLE, and its value as a predictor of poor outcome should be further validated in large longitudinal cohorts.

Association of IRF5 polymorphisms with activation of the interferon alpha pathway.

OBJECTIVE: The genetic association of interferon regulatory factor 5 (IRF5) with systemic lupus erythematosus (SLE) susceptibility has been convincingly established. To gain understanding of the effect of IRF5 variation in individuals without SLE, a study was undertaken to examine whether such genetic variation predisposes to activation of the interferon alpha (IFNalpha) pathway. METHODS: Using a computer simulated approach, 14 single nucleotide polymorphisms (SNPs) and haplotypes of IRF5 were tested for association with mRNA expression levels of IRF5, IFNalpha and IFN-inducible genes and chemokines in lymphoblastoid cell lines (LCLs) from individuals of European (CEU), Han Chinese (CHB), Japanese (JPT) and Yoruba Nigerian (YRI) backgrounds. IFN-inducible gene expression was assessed in LCLs from children with SLE in the presence and absence of IFNalpha stimulation. RESULTS: The major alleles of IRF5 rs13242262 and rs2280714 were associated with increased IRF5 mRNA expression levels in the CEU, CHB+JPT and YRI samples. The minor allele of IRF5 rs10488631 was associated with increased IRF5, IFNalpha and IFN-inducible chemokine expression in CEU (p(c)=0.0005, 0.01 and 0.04, respectively). A haplotype containing these risk alleles of rs13242262, rs10488631 and rs2280714 was associated with increased IRF5, IFNalpha and IFN-inducible chemokine expression in CEU LCLs. In vitro studies showed specific activation of IFN-inducible genes in LCLs by IFNalpha. CONCLUSIONS: SNPs of IRF5 in healthy individuals of a number of ethnic groups were associated with increased mRNA expression of IRF5. In European-derived individuals, an IRF5 haplotype was associated with increased IRF5, IFNalpha and IFN-inducible chemokine expression. Identifying individuals genetically predisposed to increased IFN-inducible gene and chemokine expression may allow early detection of risk for SLE.

MAGE-B2 autoantibody: a new biomarker for pediatric systemic lupus erythematosus.

OBJECTIVE: Melanoma-associated antigen gene B2 (MAGE-B2) encodes an embryonic antigen normally silenced after birth except in testis and placenta. We identified the MAGE-B2 gene and autoantibodies in pediatric patients with systemic lupus erythematosus (SLE) glomerulonephritis. We investigated the prevalence of MAGE-B2 autoantibodies in association with active SLE, to determine a pathogenetic role of MAGE-B2 protein through its distribution in cells and tissues. METHODS: A cross-sectional study analyzed the frequency of MAGE-B2 autoantibodies in 40 patients with pediatric SLE, 23 adult controls, and 16 patients with pediatric juvenile rheumatoid arthritis (JRA) using Western blots containing recombinant MAGE-B2. SLE Disease Activity Index 2000 (SLEDAI-2K) and British Isles Lupus Assessment Group (BILAG) index measured SLE disease activity. Tissue distribution of MAGE-B2 protein was assessed by immunohistochemistry, immunofluorescence, and Western blots. RESULTS: Seventeen (43%) of 40 pediatric SLE patients had MAGE-B2 autoantibodies as compared to 0 of 16 JRA patients and 2 of 23 adult controls. SLE disease activity was significantly higher in MAGE-B2 autoantibody-positive versus autoantibody-negative patients (SLEDAI-2K, mean 10.9 vs 5.2, p = 0.013; BILAG, mean 15.3 vs 6.3, p = 0.023). Active nephritis was more prevalent (60% vs 24%) in MAGE-B2 autoantibody-positive than autoantibody-negative SLE patients. MAGE-B2 protein was visualized in SLE kidney proximal convoluted tubules and in tumor epithelial cells, but not in lymphoblastoid cells. CONCLUSION: MAGE-B2 autoantibody appears to be a clinically relevant biomarker for pediatric SLE disease activity and nephritis.