Stem cell source-dependent reconstitution of FOXP3+ T cells after pediatric SCT and the association with allo-reactive disease.

In adult patients, regulatory CD4+FOXP3+ T cells are suggested to have a role in the control of allo-reactive disease after hematopoietic SCT (HSCT). We compared CD4+FOXP3+ T-cell reconstitution after unrelated cord blood (UCB), matched unrelated donor (MUD) and matched sibling donor (MSD) HSCT in children, starting as early as 1 week after transplantation, and analyzed the association with allo-reactive disease. A total of 30 children were included who underwent a myeloablative-conditioning regimen followed by UCB (12/30), MUD (7/30) or MSD (11/30) HSCT. These three patient groups showed significant differences in FOXP3+ T-cell reconstitution pattern. Early after UCB and MSD, but not after MUD, HSCT a peak in FOXP3+ T cells was observed. There were significant differences in activation status and Ki67 expression of the FOXP3+ T cells after UCB and MSD, respectively. FOXP3+ T-cell proportions early after HSCT and in the graft were inversely correlated with allo-reactivity. This study indicates that FOXP3 reconstitution after HSCT is dependent on the type of graft used. Furthermore, in children evaluation of FOXP3+ T-cell numbers early after HSCT and in the graft may be used to judge the risk of developing allo-reactivity after HSCT.

Lactic acid bacteria differ in their ability to induce functional regulatory T cells in humans.

BACKGROUND: Trials with probiotic lactic acid bacteria have yielded different results, which may be due to the strains used. Lactobacilli and bifidobacteria are known to be potent modulators of the immune system. The capacity of these bacteria used as probiotics to influence both T helper type 1 (Th1)- and Th2-mediated diseases has been shown before. However, the ability of strains to induce forkhead box P3 (FOXP3(+)) expressing regulatory T cells has not yet been investigated. OBJECTIVE: Test the inherent differences between strains in their capacity to induce functional regulatory T cells in human peripheral blood mononuclear cells (PBMC). METHODS: Human PBMC were co-cultured in vitro with either Bifidobacterium lactis W51, Lactobacillus acidophilus W55 or Lactobacillus plantarum W62 or an Escherichia coli control strain. The percentage of FOXP3(+) cells, the origin of the induced cells and the functionality of these cells were assessed. Results Probiotic strains differ in their capacity to induce regulatory T cells. FOXP3(+) cells were induced from CD25(-) cells and were able to suppress effector T cells. Naturally occurring regulatory T cells were not affected by co-culture with lactobacilli. IL-10 concentrations found in the supernatant showed a trend towards the same differences between strains. Blockade of IL-10 did not influence the up-regulation of FOXP3. No differences between lactic acid bacteria were found in IL-17, IFN-gamma or IL-13. CONCLUSIONS: Some probiotic strains are potent inducers of regulatory cells, while others are not. The clear differences between strains imply that an in vitro characterization of probiotic strains before application is recommended.

Regulatory T cells in autologous stem cell transplantation for autoimmune disease.

Since a decade autologous stem cell transplantation (ASCT) is successfully performed to treat patients with severe autoimmune disease. However, the mechanism of action of this intervention remains largely unknown. Scarce data from animal studies and human clinical trials indicate that, besides extensive immune ablation, restoration of regulatory immune networks is of critical importance. This review focuses on the role of naturally occurring and induced regulatory T cells in controlling immune reconstitution and restoration of immune tolerance and in preventing relapses of disease following ASCT.

Autologous stem cell transplantation in children with severe progressive systemic or polyarticular juvenile idiopathic arthritis: long-term follow-up of a prospective clinical trial.

OBJECTIVE: To assess the safety and efficacy of intensive immunosuppression followed by T cell-depleted autologous hematopoietic stem cell transplantation (ASCT) for induction of disease remission in children with refractory progressive juvenile idiopathic arthritis (JIA). METHODS: Twenty-two patients with progressive refractory JIA were followed up over a median period of 80 months after pretreatment with intensive immunosuppression followed by ASCT in a multicenter, prospective, phase II clinical trial. Hematopoietic stem cells were harvested from the patients' bone marrow, depleted of T cells, and kept frozen until used for ASCT. Pretreatment of patients consisted of a combination of antithymocyte globulin, cyclophosphamide, and low-dose total body irradiation. Patients were followed up for ASCT-related complications, recovery of hematologic and immune system parameters, and disease outcomes. RESULTS: Reconstitution of hematologic values to normal range was rapid. Recovery of immune system parameters, especially normalization of CD4+, CD45RA+ naive T cells, was delayed, occurring at >/=6 months after ASCT. The prolonged period of immune deficiency resulted in a large number of viral infections and may have contributed to the development of macrophage activation syndrome (MAS), leading to death, in 2 patients. After ASCT, 8 of the 20 evaluable patients reached complete clinical remission of their JIA, 7 were partial responders, and 5 experienced a relapse of their disease (occurring 7 years after ASCT in 1 patient). Later during followup, 2 of the patients whose disease relapsed died from infections that developed after restarting immunosuppressive medication. CONCLUSION: Intensive immunosuppression followed by ASCT resulted in sustained complete remission or marked improvement in 15 of 22 patients with progressive refractory JIA. The procedure, however, is associated with significant morbidity and risk of mortality due to prolonged and severe depression of T cell immunity. After fatal complications due to MAS were observed in some patients, the protocol was amended in 1999, to ensure less profound depletion of T cells, better control of systemic disease before transplantation, antiviral prophylaxis after transplantation, and slow tapering of corticosteroids. Following these protocol modifications, no additional ASCT-related deaths were observed among the 11 patients who received the modified treatment.

Autologous stem cell transplantation for refractory juvenile idiopathic arthritis: analysis of clinical effects, mortality, and transplant related morbidity.

OBJECTIVE: To evaluate the safety and efficacy of autologous stem cell transplantation (ASCT) for refractory juvenile idiopathic arthritis (JIA). DESIGN: Retrospective analysis of follow up data on 34 children with JIA who were treated with ASCT in nine different European transplant centres. Rheumatological evaluation employed a modified set of core criteria. Immunological reconstitution and infectious complications were monitored at three month intervals after transplantation. RESULTS: Clinical follow up ranged from 12 to 60 months. Eighteen of the 34 patients (53%) with a follow up of 12 to 60 months achieved complete drug-free remission. Seven of these patients had previously failed treatment with anti-TNF. Six of the 34 patients (18%) showed a partial response (ranging from 30% to 70% improvement) and seven (21%) were resistant to ASCT. Infectious complications were common. There were three cases of transplant related mortality (9%) and two of disease related mortality (6%). CONCLUSIONS: ASCT in severely ill patients with JIA induces a drug-free remission of the disease and a profound increase in general wellbeing in a substantial proportion of patients, but the procedure carries a significant mortality risk. The following adjustments are proposed for future protocols: (1) elimination of total body irradiation from the conditioning regimen; (2) prophylactic administration of antiviral drugs and intravenous immunoglobulins until there is a normal CD4+ T cell count.

Long-term follow-up of autologous stem cell transplantation for refractory juvenile idiopathic arthritis.

Since 1997, autologous stem cell transplantation (ASCT) had been applied to more than 40 children with polyarticular or systemic juvenile idiopathic arthritis (JIA). For this review, results of the follow-up are available from 25 children with systemic JIA and six with polyarticular JIA that were reported in detail from eight different pediatric European transplant centers. Before ASCT all children had progressive disease despite the use of corticosteroids, methotrexate (MTX) up to 1 mg/kg/week, cyclosporin (2.5 mg/kg/day) and/or anti-TNFalpha therapy. The clinical follow-up of these children ranges from 8 to 60 months (median 33 months).

The spontaneous remission of juvenile idiopathic arthritis is characterized by CD30+ T cells directed to human heat-shock protein 60 capable of producing the regulatory cytokine interleukin-10.

OBJECTIVE: To test the hypothesis that T cell reactivity to self heat-shock protein 60 (Hsp60) in patients with remitting juvenile idiopathic arthritis (JIA) is part of an antiinflammatory, regulatory mechanism. METHODS: Using peripheral blood-derived mononuclear cells (PBMCs) and synovial fluid-derived mononuclear cells (SFMCs) obtained from patients with JIA, we analyzed the expression of CD30 and the induction of regulatory cytokines in response to human and mycobacterial Hsp60. RESULTS: In oligoarticular JIA patients, in vitro activation of PBMCs and SFMCs with Hsp60 induced a high expression of CD30 on CD4+, activated (HLA-DR-positive), memory (CD45RO+) T cells. The expression of CD30 induced by human Hsp60 was much higher than that induced by mycobacterial Hsp60. In oligoarticular JIA patients with active disease, the expression of CD30 in response to human Hsp60 was paralleled by a high interleukin-10 (IL-10):interferon-gamma (IFNgamma) ratio. In addition, restimulated human Hsp60-specific T cell lines from oligoarticular JIA patients showed a high production of IL-10 and a low production of IFNgamma. In contrast, PBMCs and SFMCs from polyarticular JIA patients responded to human Hsp60 with virtually no expression of CD30 and a low IL-10:IFNgamma ratio. CONCLUSION: The results show that T cells responding to human Hsp60 in oligoarticular JIA patients express CD30, and during active phases of the disease, these T cells have a cytokine profile with a high IL-10:IFNgamma ratio. These findings suggest that in oligoarticular JIA patients, human Hsp60-specific CD4+ cells have a regulatory function and contribute to disease remission.

Myeloid related protein 8 and 14 secretion reflects phagocyte activation and correlates with disease activity in juvenile idiopathic arthritis treated with autologous stem cell transplantation.

OBJECTIVES: To determine whether myeloid related proteins (MRP8/MRP14), a complex of two S100 proteins related to neutrophil and monocyte activation, might be used as a marker for disease activity, and as an early indicator of relapse in juvenile idiopathic arthritis. PATIENTS AND METHODS: A group of 12 patients who underwent an autologous haematopoietic stem cell transplantation (ASCT) for refractory juvenile idiopathic arthritis (JIA) were studied. MRP8/MRP14 serum concentrations were determined by a sandwich enzyme linked immunosorbent assay (ELISA) as described. Improvement from baseline was described by a definition of improvement employing a core set of criteria as detailed previously by Giannini. RESULTS: After ASCT, MRP8/MRP14 serum concentrations in JIA showed a positive correlation with the Child Health Assessment Questionnaire (CHAQ; r=0.80) and erythrocyte sedimentation rate (r=0.45), but not with the total leucocyte count (r=0.26). Mean MRP8/MRP14 serum concentrations dropped markedly in the first three months after ASCT (p=0.0039) and clinical parameters of disease activity such as CHAQ markedly improved (p=0.0039). During a transient relapse there was an increase in MRP8/MRP14. CONCLUSIONS: MRP8/MRP14 serum concentration can be used as a marker for disease activity in patients who receive an ASCT for refractory JIA. This indicates a role of macrophage activation in the pathogenesis of JIA. The occurrence of MAS in three patients in this study was not preceded by significant changes in MRP8/MRP14 concentration.

Lung function abnormalities and respiratory muscle weakness in children with juvenile chronic arthritis.

In contrast to adult rheumatoid arthritis (RA) little is known about the prevalence, nature and cause of lung function abnormalities in children with juvenile chronic arthritis (JCA). The aim of this study was to determine whether children with polyarticular and systemic onset JCA have lung function abnormalities and if so, whether they are related to pulmonary disease, thoracic and/or muscular involvement. We determined lung function and disability in 31 children with polyarticular and systemic JCA. Respiratory muscle function, thorax expansion and spine mobility were determined in the same patients, as well as in 32 matched healthy children. Peak expiratory flow (PEF) and forced vital capacity (FVC) were significantly reduced in JCA patients, when compared to reference values. Thorax expansion and spine mobility were normal, compared to paired controls. Maximum inspiratory (PI,max) and expiratory (PE,max) pressures were significantly reduced in patients compared to paired control subjects. A positive correlation was found between PE,max and FVC and PEF, an inverse correlation between expiratory pressure and disability. In conclusion, children with polyarticular and systemic juvenile chronic arthritis show a pronounced impairment in respiratory muscle strength, severe enough to cause mild lung function abnormalities and an increase in disability-scores.

[Increase of reported HIV-1 infections in children in Netherlands, 1982-1997: more vertical transmission and a greater proportion of other than Dutch children]. / Toename van gemelde HIV-1-infectie bij kinderen in Nederland, 1982-1997: meer verticale transmissie en groter aandeel van allochtone kinderen.

OBJECTIVE: To document the trend of the yearly number of newly diagnosed paediatric HIV-1 infections in the Netherlands. DESIGN: Retrospective registration regarding the period January 1st 1982-December 31st 1994 and prospective registration regarding January 1st 1995-December 31st 1997. METHOD: Based on reports to the Dutch Paediatric Surveillance Unit (Nederlands Signaleringscentrum Kindergeneeskunde) numbers of paediatric HIV-1 diagnoses (0-18 years) in the Netherlands were determined prospectively. Retrospective figures were determined by asking the paediatricians also to report the HIV-1 infected children diagnosed before the first of January 1995. A comparison was made with data from the Inspectorate for Health Care (Inspectie voor de Gezondheidszorg). All reports were followed up with standard questionnaires. RESULTS: In both periods an increase in the number of newly diagnosed paediatric HIV-1 infections per year in the Netherlands was seen (1982-1994: 74 children; 1995-1997: 43 children). The majority of the parents of the HIV-1 infected children originated from outside the Netherlands (1982-1994: 57%; 1995-1997: 91%), often from HIV-endemic countries (1982-1994: 41%; 1995-1997: 77%). The main mode of infection was vertical transmission (1982-1994: 62%; 1995-1997: 84%); diagnosis in allochtonous children was made relatively late. CONCLUSION: The current rise in the absolute number of newly detected paediatric HIV-1 infections in the Netherlands is predominantly due to the growing group of children born to parents who originate from HIV-endemic countries.