Classification Criteria For Macrophage Activation Syndrome Research Articles

Tocilizumab modifies clinical and laboratory features of macrophage activation syndrome complicating systemic juvenile idiopathic arthritis

BackgroundThis study aimed to determine the influence of tocilizumab (TCZ) in modifying the clinical and laboratory features of macrophage activation syndrome (MAS) complicating systemic juvenile idiopathic arthritis (s-JIA). Furthermore, we assessed the performance of the 2016 MAS classification criteria for patients with s-JIA-associated MAS while treated with TCZ.MethodsA panel of 15 pediatric rheumatologists conducted a combination of expert consensus and analysis of real patient data. Clinical and laboratory features of s-JIA-associated MAS in 12 TCZ-treated patients and 18 untreated patients were evaluated. Possible MAS was defined as having characteristic laboratory features but lack of clinical features of MAS, or atypical MAS, or early treatment that prevented full-blown MAS.ResultsClinically, the TCZ-treated patients with s-JIA-associated MAS were less likely febrile and had significantly lower ferritin, triglyceride, and CRP levels than the untreated patients with s-JIA-associated MAS. Other laboratory features of MAS including lower platelet counts and lower fibrinogen were more pronounced in TCZ-treated patients. The TCZ-treated patients with s-JIA-associated MAS were less likely to be classified as MAS based on the MAS classification criteria (25% vs 83.3%, p < 0.01). This is ascribed to the absence of fever or insufficient ferritin elevation, compared with the untreated patients.ConclusionTCZ could modify the clinical and laboratory features of s-JIA-associated MAS. When evaluating the s-JIA patients while treated with TCZ, it is not applicable to use MAS classification criteria. Care must be taken to not underdiagnose MAS based on the MAS classification criteria.

Ferritin to Erythrocyte Sedimentation Rate Ratio: Simple Measure to Identify Macrophage Activation Syndrome in Systemic Juvenile Idiopathic Arthritis.

ObjectiveMacrophage activation syndrome (MAS) is a life‐threatening complication of systemic juvenile idiopathic arthritis (sJIA). Early diagnosis is critical. Classification criteria for MAS in sJIA perform less well in the setting of cytokine‐directed therapies. The goal herein was to explore a simple ratio of serum ferritin to the erythrocyte sedimentation rate (ESR) for diagnosis of MAS in the setting of sJIA, and to assess ferritin alone as a screening tool for identifying MAS of multiple etiologies.MethodsData from a large international cohort of sJIA patients with and without MAS, and from hospitalized patients with systemic infection (SI), were assessed for the ferritin:ESR ratio and ferritin alone to identify MAS among sJIA patients. Moreover, data from a smaller cohort of MAS patients associated with multiple etiologies and febrile hospitalized controls were explored. For both cohorts and controls, receiver operating characteristic curves (ROCs) for the ferritin:ESR ratio and ferritin alone were constructed, and areas under the curves (AUCs) were calculated. The Youden index was used to determine the optimal ferritin:ESR ratio and ferritin alone cut points for diagnosis.ResultsA ferritin:ESR ratio of 21.5 was 82% sensitive and 78% specific for diagnosing sJIA‐MAS versus active sJIA without MAS. Ferritin alone with a set sensitivity of 95% (screening tool) had an 89.3% specificity of identifying all‐cause MAS versus febrile hospitalized children.ConclusionThe ferritin:ESR ratio is a practical tool for diagnosing MAS among sJIA patients, and serum ferritin alone is a remarkable screening tool for identifying MAS among febrile hospitalized children.

Effect of Biologic Therapy on Clinical and Laboratory Features of Macrophage Activation Syndrome Associated With Systemic Juvenile Idiopathic Arthritis.

To assess performance of the 2016 macrophage activation syndrome (MAS) classification criteria for patients with systemic juvenile idiopathic arthritis (JIA) who develop MAS while treated with biologic medications. A systematic literature review was performed to identify patients with MAS while being treated with interleukin (IL)-1 and IL-6 blocking agents. Clinical and laboratory information was compared to a large previously compiled historical cohort. Eighteen publications were identified, and after removing duplicates, 35 patients treated with canakinumab and 49 patients with tocilizumab were available for analysis; 5 anakinra-treated patients were excluded due to limited numbers. MAS classification criteria were less likely to classify tocilizumab-treated patients as having MAS compared to the historical cohort or canakinumab-treated patients (56.7%, 78.5%, and 84%, respectively; P < 0.01). Patients who developed MAS while treated with canakinumab trended towards lower ferritin at MAS onset than the historical cohort (4,050 versus 5,353 ng/ml; P = 0.18) but had no differences in other cardinal clinical or laboratory features. In comparison, patients who developed MAS while treated with tocilizumab were less likely febrile and had notably lower ferritin levels (1,152 versus 5,353 ng/ml; P < 0.001). Other features of MAS were more pronounced in patients treated with tocilizumab, including lower platelet counts, lower fibrinogen, and higher aspartate aminotransferase levels. Mortality rates for patients with MAS treated with tocilizumab or canakinumab were not significantly different from the historical cohort. These findings show substantial alterations in MAS features that may limit utility of defined criteria for diagnosis of systemic JIA patients treated with biologic agents.

Development of new classification criteria for macrophage activation syndrome complicating systemic juvenile idiopathic arthritis

Macrophage activation syndrome (MAS) is a potentially fatal complication of systemic juvenile idiopathic arthritis (sJIA), whose prompt recognition and treatment are critical. However, early diagnosis of MAS is often challenging and none of the current diagnostic criteria is satisfactory. An international project aimed to develop a new set of classification criteria for MAS was recently started.