[Still's disease in children and adults]

[Adult-onset Still's disease : Diagnosis and treatment according to the new S2e guidelines of the German Society of Rheumatology (DGRh)]

Adult-onset Still's disease (AOSD) is a rare autoinflammatory disease characterized by intermittent fever and a combination of symptoms, such as an evanescent rash synchronous with fever, arthralgia/arthritis, lymphadenopathy and hepatosplenomegaly. The diagnosis is based on a characteristic constellation of symptoms and the exclusion of infections, hemato-oncological diseases, infectious diseases and alternative rheumatological causes. The systemic inflammatory reaction is reflected by high levels of ferritin and C‑reactive protein (CRP). The pharmacological treatment concept includes glucocorticoids often in combination with methotrexate (MTX) and ciclosporine (CSA) for reduction of steroids. The interleukin 1 (IL-1) receptor antagonist anakinra, the IL-1beta antibody canakinumab or an IL‑6 receptor blockage with tocilizumab (off label for AOSD) are used where there is no response to MTX or CSA. Anakinra or canakinumab can be used as a primary option in AOSD in cases of moderate and severe disease activity.

[Adult-onset Still's disease : Diagnosis and treatment according to the new S2e guidelines of the German Society of Rheumatology (DGRh)]

Adult-onset Still's disease (AOSD) is a rare autoinflammatory disease characterized by intermittent fever and a combination of symptoms, such as an evanescent rash synchronous with fever, arthralgia/arthritis, lymphadenopathy and hepatosplenomegaly. The diagnosis is based on a characteristic constellation of symptoms and the exclusion of infections, hemato-oncological diseases, infectious diseases and alternative rheumatological causes. The systemic inflammatory reaction is reflected by high levels of ferritin and C‑reactive protein (CRP). The pharmacological treatment concept includes glucocorticoids often in combination with methotrexate (MTX) and ciclosporine (CSA) for reduction of steroids. The interleukin 1 (IL-1) receptor antagonist anakinra, the IL-1beta antibody canakinumab or an IL‑6 receptor blockage with tocilizumab (off label for AOSD) are used where there is no response to MTX or CSA. Anakinra or canakinumab can be used as a primary option in AOSD in cases of moderate and severe disease activity.

Different Chronic Disorders That Fall within the Term Juvenile Idiopathic Arthritis

Juvenile idiopathic arthritis (JIA) represents a significant challenge for pediatricians who intend to diagnose and treat this pathology. The classification criteria for JIA subtypes are rigid and often do not fully satisfy the possibilities of classification in the subtype. The objective of this study was to identify clearer criteria for classifying JIA subtypes. The 2019 expert committee meeting (PRINTO) shows the difficulties of this classification and proposes new research directions for the identification of disease subtypes. Four different chronic disorders are used to define JIA in a concise and easy to follow classification system. However, dates from the literature suggest that at least 10% of cases are still difficult to classify. Possibly in the future, different classifications of JIA based on pathophysiological and genetic criteria would be necessary.

Schnitzler syndrome

Schnitzler syndrome is a very rare acquired systemic disease with many similarities to hereditary autoinflammatory syndromes. The main characteristics are generalized exanthema and IgM monoclonal gammopathy. Other clinical features include fever, muscle, bone, and/or joint pain, and lymphadenopathy. About 15-20% of patients with Schnitzler syndrome develop lymphoproliferative diseases and, in rare cases, amyloid A (AA) amyloidosis can occur if the disease is not treated. Activation of the innate immune system, especially interleukin (IL)-1β, is central to the pathogenesis of disease. Consequently, complete control of disease symptoms can be achieved in 80% of patients by treatment with the IL-1 receptor antagonist anakinra.

[Schnitzler syndrome]

Schnitzler syndrome is a very rare acquired systemic disease with many similarities to hereditary autoinflammatory syndromes. The main characteristics are generalized exanthema and a monoclonal gammopathy with IgM. Other clinical features include fever, muscle, bone and/or joint pain, and lymphadenopathy. About 15-20% of patients with Schnitzler syndrome develop lymphoproliferative diseases and, in rare cases, amyloid A (AA) amyloidosis can occur if the disease is not treated. Activation of the innate immune system, especially interleukin(IL)-1β, is central in the pathogenesis of the disease. Consequently, complete control of disease symptoms can be achieved in 80% of patients by treatment with the IL-1 receptor antagonist anakinra.

[Schnitzler syndrome]

Schnitzler syndrome is a very rare acquired systemic disease with many similarities to hereditary autoinflammatory syndromes. The main characteristics are generalized exanthema and a monoclonal gammopathy with IgM. Other clinical features include fever, muscle, bone and/or joint pain, and lymphadenopathy. About 15-20% of patients with Schnitzler syndrome develop lymphoproliferative diseases and, in rare cases, amyloid A (AA) amyloidosis can occur if the disease is not treated. Activation of the innate immune system, especially interleukin(IL)-1β, is central in the pathogenesis of the disease. Consequently, complete control of disease symptoms can be achieved in 80% of patients by treatment with the IL-1 receptor antagonist anakinra.

Application of the international league against rheumatism classification criteria for systemic juvenile idiopathic arthritis as a prognostic factor in patients with adults-onset Still's disease

BACKGROUND

Adult-onset Still's disease (AOSD) is an adult form of systemic juvenile idiopathic arthritis (JIA) that differs from the latter in its classification. This study evaluated the concordance between the International League Against Rheumatism (ILAR) criteria for systemic JIA and the Yamaguchi criteria and then compared their possible prognostic value in patients with AOSD.

METHODS

In a retrospective review of 169 adults with suspected AOSD, patients were classified according to the Yamaguchi or ILAR criteria. Then the concordance in cross-referencing the other group with the different criteria was investigated and the sensitivity and specificity of each set of criteria were determined. Disease activity markers in AOSD patients were correlated with positivity according to both systems.

RESULTS

Concordance was good in patients with suspected AOSD (k = 0.7144, p <  0.001) and low in those with a diagnosis of AOSD (k = 0.3787, p <  0.001). The sensitivity of the ILAR criteria in AOSD patients was 0.8864 (95% confidence interval (CI): 0.8322-0.9405), and the specificity was 0.7838 (0.6511, 0.9164). Positivity according to the ILAR criteria correlated with the systemic score (r = 0.763, p <  0.0001) and C-reactive protein levels (r = 0.183, p = 0.0356) and was associated with a relapse (odds ratio: 1.589, 95% CI: 1.043-2.421), macrophage activation syndrome (MAS; odds ratio: 1.993, 95% CI: 1.218-3.263) and care in the intensive care unit (ICU; odds ratio: 2.087, 95% CI: 1.086-4.011).

CONCLUSIONS

In AOSD patients, there is fair concordance between the Yamaguchi and ILAR criteria for systemic JIA. Positive ILAR criteria may be useful for identifying AOSD patients at high risk for relapse, MAS and the need for ICU care. Further studies including larger populations from several centers are needed to confirm our results regarding the utility of the ILAR criteria in AOSD patients.