Adult-onset Still's disease complicated by macrophage activation syndrome during pregnancy: a case-based review

Adult-onset Still's disease is a rare, systemic inflammatory rheumatic disease characterized by recurrent fevers, arthritis, and an evanescent rash. One of the most serious hematologic derangements that can be seen with adult-onset Still's disease is macrophage activation syndrome. Macrophage activation syndrome is characterized by activation of lymphocytes, resulting in a cytokine storm and hemophagocytosis in the bone marrow, along with multi-organ failure. Adult-onset Still's disease with macrophage activation syndrome first presenting during pregnancy is exceptionally rare; here, we report two unique cases of such a presentation and review the pertinent literature. Both of our cases presented critically ill with end-organ failure, and responded to immunosuppression; fetal demise was present in one and an emergency caesarean section with a viable fetus was performed in the other patient. Maternal outcomes were favorable in both cases and both patients did well long-term with systemic therapy. Systemic immunosuppression, particularly anti-IL1 therapy, may be considered as treatment for this rare and life-threatening condition when presenting during pregnancy.

[Autoinflammatory syndromes]

The concept of autoinflammation includes a heterogeneous group of monogenic and polygenic diseases. These are characterized by excessive activation of the innate immune system without antigen-specific T cells or autoantibodies. The diseases are characterized by periodic episodes of fever and increased inflammation parameters. Monogenic diseases include familial Mediterranean fever (FMF) and the newly described VEXAS (vacuoles, E1 enzyme, X‑linked, autoinflammatory, somatic) syndrome. Heterogeneous diseases include adult-onset Still's disease and Schnitzler syndrome. Treatment is aimed at preventing the excessive inflammatory reaction in order to avoid long-term damage, such as amyloid A (AA) amyloidosis.

[Autoinflammatory syndromes]

The concept of autoinflammation includes a heterogeneous group of monogenic and polygenic diseases. These are characterized by excessive activation of the innate immune system without antigen-specific T cells or autoantibodies. The diseases are characterized by periodic episodes of fever and increased inflammation parameters. Monogenic diseases include familial Mediterranean fever (FMF) and the newly described VEXAS (vacuoles, E1 enzyme, X‑linked, autoinflammatory, somatic) syndrome. Heterogeneous diseases include adult-onset Still's disease and Schnitzler syndrome. Treatment is aimed at preventing the excessive inflammatory reaction in order to avoid long-term damage, such as amyloid A (AA) amyloidosis.

The spectrum of hemophagocytic lymphohistiocytosis: a retrospective study comparing adult macrophage activation syndrome to malignancy-associated hemophagocytic lymphohistiocytosis

Secondary hemophagocytic lymphohistiocytosis (sHLH) is a life-threatening inflammatory syndrome that can be triggered by autoimmune diseases, malignancy, or infection. In rheumatologic patients, sHLH is referred to as macrophage activation syndrome (MAS). Differentiating between triggers is important for prompt treatment and prognosis. Data comparing subsets of sHLH are limited due to the rarity of this disease. We aim to explore differences in clinical features that may differentiate MAS from malignancy-associated HLH (mHLH) patients. We conducted a single-center retrospective study assessing clinical characteristics, laboratory parameters, treatment regimens and outcomes in 34 patients with sHLH over a 16 year period. We compared patients with MAS to those with mHLH. Hepatomegaly was not present in the MAS group but was present in the mHLH group (0 vs. 25%, p = 0.024). MAS patients had on average nearly double the concentration of platelets at 50.0 (IQR: 31.0–78.0 Kµ/L) vs. 29.0 Kµ/L (IQR: 14.0–37.5 Kµ/L), p = 0.003. Soluble IL-2R concentrations were four times lower in the MAS group with a median soluble IL-2R concentration of 6814.5 kU/L (IQR: 2101–2610 kU/L) vs. 27972.0 kU/L (IQR: 12,820–151,650 kU/L), p = 0.010. The MAS group fared better overall than the mHLH group but was not statistically significant (mortality 22 vs. 44%, p = 0.18). MAS and mHLH patients exhibited different laboratory parameters and clinical features, most notably differences in platelet counts, soluble IL-2R concentration and hepatomegaly, which may help differentiate these conditions early in their course.

The role of 18F-fluorodeoxyglucose positron emission tomography in the assessment of disease activity of adult-onset Still's disease

BACKGROUND/AIMS

18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) has been suggested as a reliable imaging technique for monitoring of disease activity in patients with adult-onset Still's disease (AOSD). Therefore, we investigated the clinical significance of 18F-FDG PET/CT in Korean AOSD patients.

METHODS

Thirteen AOSD patients were included in the study. The PET/CT images were evaluated with visual and semiquantitative method using standardized uptake values (SUVs).

RESULTS

The presence of increased 18F-FDG uptake was noted in 90% of clinically active AOSD patients. 18F-FDG uptake was located in the lymph node, spleen, and bone marrow. Visual grade and SUV intensity of lymph node was significantly correlated with the systemic score of AOSD. Visual grade of spleen was significantly correlated with the systemic score, erythrocyte sedimentation rate (ESR), and ferritin. Additionally, visual grade and SUV intensity of bone marrow was significantly correlated with the systemic score, ESR, leukocyte, and neutrophil.

CONCLUSIONS

Visual grade and SUV intensity of lymph node, spleen, and bone marrow on 18F-FDG PET/CT scan showed significant correlations with known disease activity markers. The data suggest that 18F-FDG PET/CT scan may be a useful imaging technique for evaluation of disease activity in AOSD patients.