The challenge of early diagnosis of autoimmune lymphoproliferative syndrome in children with suspected autoinflammatory/autoimmune disorders

OBJECTIVES

To test the usefulness of an extended panel of lymphocyte subsets (LS) in combination with Oliveira's diagnostic criteria for the identification of autoimmune lymphoproliferative syndrome (ALPS) in children referred to a pediatric rheumatology center.

METHODS

patients referred from 2015 to 2018 to our Rheumatology Unit for an autoimmune or autoinflammatory condition were retrospectively analyzed. Oliveira's required criteria (chronic lymphoproliferation and elevated DNT) were applied as first screening. Flow cytometry study included double negative CD4-CD8-TCR αβ+T lymphocytes (DNT), CD25+CD3+, HLA-DR+CD3+T cells, B220+T cells, and CD27+B cells. Data were analyzed with an univariate logistic regression analysis, followed by a multivariate analysis. Sensitivity and specificity of the Oliveira's required criteria were calculated.

RESULTS

264 patients were included in the study and classified as: i) autoimmune diseases (26); ii) juvenile idiopathic arthritis (JIA) (35) iii) monogenic systemic autoinflammatory disease (SAID) (27); iv) PFAPA syndrome (100); v) systemic undefined recurrent fever (SURF) (45); vi) undetermined-SAID (14); vii) ALPS (17). Oliveira's required criteria displayed a sensitivity of 100% and specificity of 79%. When compared with other diseases the TCRαβ+B220+ lymphocytes were significantly increased in ALPS patients. The multivariate analysis revealed 5 clinical/laboratory parameters positively associated to ALPS: splenomegaly, female gender, arthralgia, elevated DNT and TCRαβ+B220+lymphocytes.

CONCLUSIONS

Oliveira's required criteria are useful for the early suspicion of ALPS. TCRαβ+B220+ lymphocytes should be added in the diagnostic work-up of patients referred to pediatric rheumatology unit for a suspected autoimmune or autoinflammatory condition, providing a relevant support in the early diagnosis of ALPS.

Clinical Significance of Serum Soluble TNF Receptor I/II Ratio for the Differential Diagnosis of Tumor Necrosis Factor Receptor-Associated Periodic Syndrome From Other Autoinflammatory Diseases

Objectives: Genetic analysis of TNFRSF1A can confirm the diagnosis of tumor necrosis factor receptor-associated periodic syndrome (TRAPS), but interpretation of the pathogenesis of variants of unknown significance is sometimes required. The aim of this study was to evaluate the clinical significance of serum soluble tumor necrosis factor receptor type I (sTNFR-I)/II ratio to differentiate TRAPS from other autoinflammatory diseases. Methods: Serum sTNFR-I and sTNFR-II levels were measured using an enzyme-linked immunosorbent assay in patients with TRAPS (n = 5), familial Mediterranean fever (FMF) (n = 14), systemic juvenile idiopathic arthritis (s-JIA) (n = 90), and Kawasaki disease (KD) (n = 37) in the active and inactive phase, along with healthy controls (HCs) (n = 18). Results: In the active phase, the serum sTNFR-I/II ratio in patients with s-JIA, KD, and FMF was significantly elevated compared with that in HCs, whereas it was not elevated in patients with TRAPS. In the inactive phase, the serum sTNFR-I/II ratio in patients with s-JIA and FMF was significantly higher compared with that in HCs, and the ratio was lower in TRAPS patients than in patients with s-JIA and FMF. Conclusions: Low serum sTNFR-I/II ratio in the active and inactive phase might be useful for the differential diagnosis of TRAPS and other autoinflammatory diseases.

A case report of a novel compound heterozygous mutation in a Brazilian patient with deficiency of Interleukin-1 receptor antagonist (DIRA)

BACKGROUND

Deficiency of the natural antagonist of interleukin-1 was first described in 2009 and so far 20 patients has been reported. In Brazil just two cases have been reported both carrying the same homozygous 15 bp deletion. Blocking interleukin-1 has changed rate survival for DIRA patients. The use of anakinra and rilonacept has been reported safe and efficient, whereas the selective blockade of interleukin-1 beta, using the monoclonal antibody canakinumab has been reported in a single case only.

CASE PRESENTATION

Here we report a case of a 7 years old Brazilian boy that presented with recurrent episodes of systemic inflammation with severe disabling osteomyelitis with mild pustular skin rash. A Next Generation Sequencing gene panel allowed to detect two pathogenic mutations in the IL1RN gene, described in compound heterozygosity. Corticosteroids was effective in controlling inflammation and anti-IL1 beta blocker triggered disease flare. Complete clinical control could be achieved using IL-1 receptor antagonist.

CONCLUSIONS

DIRA is a severe, life threatening autoinflammatory condition with low numbers of patients described all over the world. The mutation p.Asp72_Ile76del in IL1RN is presented in all Brazilian DIRA patients already described and p.Q45* (rs1019766125) is a new mutation affecting the IL1RN gene. Following the pathogenesis of DIRA, blocking both subunits of interleukin one as well as antagonizing the receptor using anakinra or rilonacept seems to be effective. There is just one report using canakinumab for the treatment of DIRA and this is the first report of disease flare using this drug.

Serum leptin, resistin, visfatin and adiponectin levels in tumor necrosis factor receptor-associated periodic syndrome (TRAPS)

OBJECTIVES

The aims of our study were to evaluate serum leptin, resistin, visfatin and adiponectin levels in patients with tumour necrosis factor receptor-associated periodic syndrome (TRAPS), in comparison to healthy controls, and to correlate their levels to parameters of disease activity and/or severity.

METHODS

Serum leptin, resistin, visfatin and adiponectin levels were obtained from 14 TRAPS patients carrying mutations involving cysteine residues, from 16 TRAPS patients carrying other mutations, and from 16 healthy controls. Demographic, clinical and laboratory parameters, including amyloidosis were entered for each patient. Comparisons between groups as well as reciprocal comparisons have been evaluated.

RESULTS

Serum leptin, resistin, visfatin and adiponectin did not significantly differ among the 3 groups. Patients carrying cysteine residues mutations showed lower visfatin serum levels than patients carrying other mutations (p<0.02). Serum leptin significantly correlated with the number of attacks/year (multiple R=0.32, multiple adjusted R2= 0.19, p <0.03). Serum adiponectin levels significantly correlated with the presence of amyloidosis (multiple R=0.79, multiple adjusted R2=0.57, p<0.03). Adiponectin values were a significant predictor for amyloidosis (AUC 0.75, 95 CI: 0.56-0.94, p<0.03), with a predicting cut-off value set at 23.16 pg/ml, the predictive positive value was 53.8%. Visfatin serum levels resulted respectively related to leptin (rs=0.42, r2=0.18, p<0.02) and to resistin (rs=0.57, r2=0.32, p<0.01) serum levels; whilst leptin and resistin serum levels did not reciprocally correlate.

CONCLUSIONS

Although a prospective design study and larger cohort are mandatory, adipokines serum levels and their correlations with parameters of disease activity and/or severity seem to show a baseline pattern in TRAPS patients.