Targeted multiomics in childhood-onset SLE reveal distinct biological phenotypes associated with disease activity: results from an explorative study

OBJECTIVE

To combine targeted transcriptomic and proteomic data in an unsupervised hierarchical clustering method to stratify patients with childhood-onset SLE (cSLE) into similar biological phenotypes, and study the immunological cellular landscape that characterises the clusters.

METHODS

Targeted whole blood gene expression and serum cytokines were determined in patients with cSLE, preselected on disease activity state (at diagnosis, Low Lupus Disease Activity State (LLDAS), flare). Unsupervised hierarchical clustering, agnostic to disease characteristics, was used to identify clusters with distinct biological phenotypes. Disease activity was scored by clinical SELENA-SLEDAI (Safety of Estrogens in Systemic Lupus Erythematosus National Assessment-Systemic Lupus Erythematosus Disease Activity Index). High-dimensional 40-colour flow cytometry was used to identify immune cell subsets.

RESULTS

Three unique clusters were identified, each characterised by a set of differentially expressed genes and cytokines, and by disease activity state: cluster 1 contained primarily patients in LLDAS, cluster 2 contained mainly treatment-naïve patients at diagnosis and cluster 3 contained a mixed group of patients, namely in LLDAS, at diagnosis and disease flare. The biological phenotypes did not reflect previous organ system involvement and over time, patients could move from one cluster to another. Healthy controls clustered together in cluster 1. Specific immune cell subsets, including CD11c+ B cells, conventional dendritic cells, plasmablasts and early effector CD4+ T cells, differed between the clusters.

CONCLUSION

Using a targeted multiomic approach, we clustered patients into distinct biological phenotypes that are related to disease activity state but not to organ system involvement. This supports a new concept where choice of treatment and tapering strategies are not solely based on clinical phenotype but includes measuring novel biological parameters.

Serum IFNα2 levels are associated with disease activity and outperform IFN-I gene signature in a longitudinal childhood-onset SLE cohort

OBJECTIVE

To study the association of serum IFNα2 levels measured by ultrasensitive single-molecule array (Simoa) and interferon type I gene signature (IGS) with disease activity and determine whether these assays can mark disease activity states in a longitudinal cohort of childhood-onset SLE patients.

METHODS

Serum IFNα2 levels were measured in 338 samples from 48 cSLE patients and 67 healthy controls using IFNα Simoa assay. Five gene IGS was measured by RT-PCR in paired whole blood samples. Disease activity was measured by clinical SELENA-SLEDAI and BILAG-2004. Low disease activity was defined by Low Lupus Disease Activity State (LLDAS) and flares were characterized by SELENA-SLEDAI flare index. Analysis was performed using linear mixed models.

RESULTS

A clear positive correlation was present between serum IFNα2 levels and the IGS (r = 0.78, p < 0.0001). Serum IFNα2 levels and IGS showed the same significant negative trend in the first three years after diagnosis. In this timeframe, mean baseline serum IFNα2 levels decreased with 55.1% (Δ 201 fg/mL, p < 0.001) to a mean value of 164 fg/mL, which was below the calculated threshold of 219.4 fg/mL, which discriminated between patients and healthy controls. In the linear mixed model, serum IFNα2 levels were significantly associated with both cSELENA-SLEDAI and BILAG-2004, while the IGS did not show this association. Both IFN-I assays were able to characterize LLDAS and disease flare in ROC analysis.

CONCLUSIONS

Serum IFNα2 levels measured by Simoa technology are associated with disease activity scores and characterize disease activity states in cSLE.

OUP accepted manuscript

Objectives

Clinical phenotyping and predicting treatment responses in SLE patients is challenging. Extensive blood transcriptional profiling has identified various gene modules that are promising for stratification of SLE patients. We aimed to translate existing transcriptomic data into simpler gene signatures suitable for daily clinical practice.

Methods

Real-time PCR of multiple genes from the IFN M1.2, IFN M5.12, neutrophil (NPh) and plasma cell (PLC) modules, followed by a principle component analysis, was used to identify indicator genes per gene signature. Gene signatures were measured in longitudinal samples from two childhood-onset SLE cohorts (n = 101 and n = 34, respectively), and associations with clinical features were assessed. Disease activity was measured using Safety of Estrogen in Lupus National Assessment (SELENA)-SLEDAI. Cluster analysis subdivided patients into three mutually exclusive fingerprint-groups termed (1) all-signatures-low, (2) only IFN high (M1.2 and/or M5.12) and (3) high NPh and/or PLC.

Results

All gene signatures were significantly associated with disease activity in cross-sectionally collected samples. The PLC-signature showed the highest association with disease activity. Interestingly, in longitudinally collected samples, the PLC-signature was associated with disease activity and showed a decrease over time. When patients were divided into fingerprints, the highest disease activity was observed in the high NPh and/or PLC group. The lowest disease activity was observed in the all-signatures-low group. The same distribution was reproduced in samples from an independent SLE cohort.

Conclusions

The identified gene signatures were associated with disease activity and were indicated to be suitable tools for stratifying SLE patients into groups with similar activated immune pathways that may guide future treatment choices.

LLDAS is an attainable treat-to-target goal in childhood-onset SLE

OBJECTIVES

To study whether clinical remission (CR) and Low Lupus Disease Activity State (LLDAS) are achievable goals in childhood-onset SLE.

METHODS

Data on medication use and disease activity were prospectively collected. LLDAS was defined as Safety of Estrogen in Lupus Erythematosus National Assesment-SLE disease Activity Index (SELENA-SLEDAI) ≤4 with zero scores for renal, Central Nervous System (CNS), serositis, vasculitis and constitutional components, no increase in any SLEDAI component since the previous visit, PGA ≤1, and prednisone dose ≤7.5 mg/day. CR on treatment (Tx) was defined as a Physician Global Assessment <0.5, SELENA-SLEDAI=0, with prednisone ≤5 mg/day and maintenance treatment with immunosuppressives. CR off Tx was the same but without prednisone or other immunosuppressive usage.

RESULTS

51 patients (700 visits) were included. Within 3 months after diagnosis, 94.1% of children were treated with hydroxychloroquine and 60.8% with prednisone. Prednisone dosage decreased from a median of 0.74 mg/kg/day at diagnosis to 0.44 mg/kg/day at 3 months and 0.16 mg/kg/day at 6 months after diagnosis. Use of mycophenolate mofetil increased from 25.5% to 56.9% within 6 months after diagnosis. All children achieved LLDAS (median 186 days) and 72.5% remained in LLDAS >50% of time. 52.9% children achieved CR on Tx, and only 21.6% children achieved CR off Tx.

CONCLUSIONS

LLDAS is an attainable treat-to-target goal in contrast to CR on and off Tx. Even more, LLDAS can be reached with limited use of corticosteroids with early introduction of immunosuppressives.

Systematic review and collaborative recalculation of 133,693 incident cases of schizophrenia

BACKGROUND

This systematic review and collaborative recalculation was set up to recalculate schizophrenia incidence rates from previously published studies by age and sex.

METHOD

PubMed, EMBASE and PsycINFO databases were searched (January 1950 to December 2009) for schizophrenia incidence studies. Numerator and population data were extracted by age, sex and, if possible, study period. Original data were requested from the authors to calculate age- and sex-specific incidence rates. Incidence rate ratios (IRRs) with their 95% confidence intervals (CIs) were computed by age and sex from negative binomial regression models.

RESULTS

Forty-three independent samples met inclusion criteria, yielding 133 693 incident cases of schizophrenia for analysis. Men had a 1.15-fold (95% CI 1.00-1.31) greater risk of schizophrenia than women. In men, incidence peaked at age 20-29 years (median rate 4.15/10,000 person-years, IRR 2.61, 95% CI 1.74-3.92). In women, incidence peaked at age 20-29 (median rate 1.71/10,000 person-years, IRR 2.34, 95% CI 1.66-3.28) and 30-39 years (median rate 1.24/10,000 person-years, IRR 2.25, 95% CI 1.55-3.28). This peak was followed by an age-incidence decline up to age 60 years that was stronger in men than in women (χ² = 57.90, p < 0.001). The relative risk of schizophrenia was greater in men up to age 39 years and this reversed to a greater relative risk in women over the age groups 50-70 years. No evidence for a second incidence peak in middle-aged women was found.

CONCLUSIONS

Robust sex differences exist in the distribution of schizophrenia risk across the age span, suggesting differential susceptibility to schizophrenia for men and women at different stages of life.

Cognitive functioning and age at onset in non-affective psychotic disorder

OBJECTIVE

Age at psychosis onset has been related to variability in cognitive functioning, but its effect may be mediated by demographic and clinical factors. The aim of the current study was to study the contribution of age at onset, as well as demographic and illness characteristics, to variation in cognitive functioning in patients with schizophrenia spectrum disorder.

METHOD

Patients (n = 1053) and healthy controls (n = 631) underwent comprehensive neuropsychological and clinical assessments. The effect of age at onset on age-standardized cognitive test scores was assessed with multiple linear regression analyses. Mediation by illness and demographic factors was tested using a multiple mediation Sobel test.

RESULTS

A diagnosis of schizophrenia, higher antipsychotic dose, and more negative symptoms were associated with earlier onset of illness, while female sex and a more chronic course were associated with later illness onset. Furthermore, earlier onset was associated with worse performance on immediate recall and sustained attention. However, male sex, more negative symptoms, and higher antipsychotic dose mediated the effect of age at onset on memory, while negative symptoms explained its association with attention/vigilance.

CONCLUSION

Greater impairment in memory and attention in early-onset psychosis may be explained by features indicative of underlying neurodevelopmental vulnerability.

[The costs and benefits of an integrated approach to dementia]

BACKGROUND

An integrated approach to dementia is generally recommended because no one discipline is adequately equipped it deal with the complex psychic, physical and social problems that are inherent in dementia. A multidisciplinary approach, however, leads inevitably to higher costs. It is not known what the cost/benefit ratio will be.

AIM

To describe our research into the costs and benefits of an integrated approach to dementia involving the use of a diagnostic research centre for psycho-geriatrics and thereafter to compare our findings with the results of other studies of the costs and benefits of an integrated approach.

METHOD

We performed a prospective and randomised efficiency study and we compared our findings with the results of other studies of the costs and benefits of an integrated approach. We reviewed recent literature.

RESULTS

The DRC-PG was more effective than normal care as far as the patients' quality of life was concerned, but was not more expensive. It can therefore be regarded as a cost-effective facility for ambulatory patients with dementia. Three other studies provided additional empirical evidence of the success of a similar integrated approach in various sectors involved in the care of patients with dementia.

CONCLUSION

An integrated approach with regard to the diagnosis, treatment and management of dementia produces favourable results. More research is needed into the efficacy and cost-effectiveness of integrated care programmes. This should result in improvements in the care and treatment of patients with dementia.