PADI4 and IL-33 gene polymorphisms associated with differential susceptibility to juvenile-onset systemic lupus erythematosus and juvenile idiopathic arthritis in Chinese children

BACKGROUND

Juvenile systemic lupus erythematosus (JSLE) and juvenile idiopathic arthritis (JIA) are two common types of autoimmune diseases in children with unclear pathogenesis. Both peptidyl arginine deiminase type IV (PADI4) and interleukin 33 (IL-33) are the key molecular involved in immune responses in autoimmune diseases. Usually, it may share the same risk genetic alleles for autoimmune diseases.

METHODS

So measurement of PADI4 and IL-33 polymorphisms was conducted with 303 healthy controls, 144 JSLE patients and 160 JIA patients in this study.

RESULTS

It demonstrated that there was a significant association between PADI4 genotypes (rs2240340: CT, CT + CC), IL-33 genotype (rs1929992: TT) and JSLE susceptibility in Southwest China population. While no significant association with the risk of JIA were observed no matter at allelic or genotypic levels.

CONCLUSIONS

Our study reveals the importance of PADI4 and IL-33 polymorphisms with JSLE risk and their roles in the development of the diseases need more further researches.

Toward the development of criteria for global flares in juvenile systemic lupus erythematosus

OBJECTIVE

To develop a definition of global flare in juvenile systemic lupus erythematosus (SLE) and derive candidate criteria for measuring juvenile SLE flares.

METHODS

Pediatric rheumatologists answered 2 Delphi questionnaires to achieve consensus on a common definition of juvenile SLE flare and identify variables for use in candidate flare criteria. The diagnostic accuracy of these candidate flare criteria was tested with data from juvenile SLE patients (n = 98; 623 visits total). Physician-rated change in the juvenile SLE course (worsening, yes/no) between visits served as the criterion standard.

RESULTS

There was 96% consensus that a "a flare is a measurable worsening of juvenile SLE disease activity in at least one organ system, involving new or worse signs of disease that may be accompanied by new or worse SLE symptoms. Depending on the severity of the flare, more intensive therapy may be required." Variables suggested for use in flare criteria were: physician-rated disease activity (V1), patient well-being, protein:creatinine ratio, a validated disease activity index (V2), the Child Health Questionnaire physical summary score (V3), anti-double-stranded DNA antibodies, erythrocyte sedimentation rate, and complement levels. Using multiple logistic regression, several candidate flare criteria were derived with area under the receiver operating characteristic curve (AUC) as high as 0.92 (sensitivity >or=85%, specificity >or=85%); classification and regression tree analysis suggested that V1, V2, and V3 suffice to identify juvenile SLE flares (AUC 0.81; sensitivity = 64%, specificity = 86%).

CONCLUSION

Consensus about a definition of global disease flare for juvenile SLE has been obtained and promising candidate flare criteria have been developed. These will need further assessment of their ease of use and accuracy in prospective study.

Prospective validation of the provisional criteria for the evaluation of response to therapy in childhood-onset systemic lupus erythematosus

OBJECTIVE

To prospectively validate the provisional criteria for the evaluation of response to therapy in children with systemic lupus erythematosus (SLE).

METHODS

In this multicenter study, childhood-onset SLE patients (n = 98; 81 girls, 17 boys, 50% white, 88% non-Hispanic) were followed every 3 months for up to 7 visits (total number of visits 623). The 5 childhood-onset SLE core response variables were obtained at the time of each visit: 1) physician assessment of overall disease activity, 2) parent assessment of patient well-being, 3) Child Health Questionnaire, 4) proteinuria, and 5) global disease activity measure score, as measured by the European Consensus Lupus Activity Measure (ECLAM), the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI), or the Systemic Lupus Activity Measure (SLAM). Physician-rated relevant changes in the disease course (clinically relevant improvement, no change in disease, or worsening) between visits served as the criterion standard. Mixed models were used to assess the diagnostic accuracy of the 4 highest-ranked provisional definitions of response to therapy.

RESULTS

There were 89 episodes of clinically relevant improvement between 2 consecutive visits, and 448 episodes without improvement. Irrespective of the choice of the global disease activity measure (ECLAM, SLAM, SLEDAI), sensitivities of all 4 highest-ranked definitions were low (all < or =31%), whereas their specificities were excellent (all >88%). Using logistic models, alternative definitions can be developed with both 80% sensitivity and specificity.

CONCLUSION

The provisional criteria of response to therapy in childhood-onset SLE may have considerably lower sensitivity than previously reported. Additional validation in clinical trials is necessary to further evaluate the measurement properties of the provisional Paediatric Rheumatology International Trials Organisation/American College of Rheumatology criteria for response to therapy in children with SLE.