Adult Still's disease. A new consideration in pyrexia of unknown origin

A Streamlined Diagnostic Process Improved the Outcomes of Patients with Adult-Onset Still's Disease: A Single-Center Retrospective Observational Study

INTRODUCTION

The diagnosis of adult-onset Still's disease (AOSD) is often delayed due to its clinical heterogeneity and lack of pathognomic features. Hence, there is an unmet need for an efficient diagnostic process. The major aim of this study was to compare the differences in disease outcomes between two groups of AOSD patients with and without implementation of the streamlined diagnostic process (SDP).

METHODS

Of 172 febrile patients with skin rash and/or arthralgia, 112 individuals had AOSD. The tentative diagnosis of AOSD or non-AOSD was made with or without the SDP implementation. The selection criteria for AOSD outcomes analysis were as follows: (1) age at study entry older than 20 years, (2) fulfillment of the Yamaguchi criteria for AOSD diagnosis, and (3) a follow-up period longer than 6 months after initiation of therapy. Three outcome parameters were evaluated, including diagnosis lag period, the proportion of "early diagnosis," and the proportion of achieving disease remission after a 6-month therapy.

RESULTS

The SDP was implemented for expediting AOSD diagnosis in 41 (36%) enrolled patients (SDP-implemented group). The diagnosis lag period was significantly shorter in the SDP-implemented group (median 2.0 weeks, interquartile range [IQR] 1.0-2.5 weeks) than in the non-SDP-implemented group (4.0 weeks, IQR 2.0-6.0 weeks, p < 0.001). A significantly higher proportion of "early diagnosis" was also found in the SDP-implemented group (75.6%) compared with the non-SDP-implemented group (33.8%, p < 0.001). We revealed a significantly higher proportion of achieving remission in the SDP-implemented group (85.4%) compared with the non-SDP-implemented group (67.6%, p < 0.05). Logistic regression analysis revealed SDP implementation as a potential predictor of achieving disease remission.

CONCLUSIONS

Implementing an SDP for expediting diagnosis could improve outcomes for AOSD patients. This diagnostic process increased the early diagnosis rate and led to a higher disease remission rate. However, the beneficial effects of SDP implementation need further external validation.

Increased Lipid Peroxidation May Be Linked to Ferritin Levels Elevation in Adult-Onset Still's Disease

Lipid peroxidation (LPO) and hyper-ferritinemia are involved in inflammatory responses. Although hyper-ferritinemia is a characteristic of AOSD, its link to LPO remains unclear. We investigated the association between LPO and ferritin expression, and evaluated the relationship between LPO-related metabolites and inflammatory parameters. Mean fluorescence intensity (MFI) of LPO (C11-Biodipy^581/591)-expressing PBMCs/monocytes in AOSD patients and healthy control (HC) subjects was determined by flow-cytometry analysis. Expression of ferritin and cytokines on PBMCs/macrophages was examined by immunoblotting. Plasma levels of LPO-related metabolites and cytokines were determined by ELISA and the MULTIPLEX platform, respectively. LPO MFI on PBMCs/monocytes were significantly higher in patients (median 4456 and 9091, respectively) compared with HC (1900, p < 0.05, and 4551, p < 0.01, respectively). Patients had higher ferritin expression on PBMCs (mean fold, 1.02) than HC (0.55, p < 0.05). Their ferritin expression levels on PBMCs stimulated with LPO inducers erastin or RSL3 (2.47 or 1.61, respectively) were higher than HC (0.84, p < 0.05, or 0.74, p < 0.01). Ferritin expression on erastin-treated/IL-1β-treated macrophages from patients were higher than those from HC (p < 0.001). The elevated levels of LPO-related metabolites, including malondialdehyde and 4-hydroxyalkenals, were positively correlated with disease activity scores, suggesting LPO involvement in AOSD pathogenesis. Increased ferritin expression on PBMCs/macrophages stimulated with LPO inducers indicates a link between LPO and elevated ferritin.

An Update on the Pathogenic Role of Macrophages in Adult-Onset Still's Disease and Its Implication in Clinical Manifestations and Novel Therapeutics

Increasing evidence indicates a pivotal role of macrophages in innate immunity, which contributes to the pathogenesis of adult-onset Still's disease (AOSD). Despite the available reviews that summarized the pathogenic role of proinflammatory cytokines in AOSD, a systematic approach focusing on the crucial role of macrophages in this disease is still lacking. This review summarizes the updated functions of macrophages in AOSD and their implication in clinical manifestations and therapeutics. We searched the MEDLINE database using the PubMed interface and reviewed the English-language literature as of 31 March 2021, from 1971 to 2021. We focus on the existing evidence on the pathogenic role of macrophages in AOSD and its implication in clinical characteristics and novel therapeutics. AOSD is an autoinflammatory disease mainly driven by the innate immune response. Among the innate immune responses, macrophage activation is a hallmark of AOSD pathogenesis. The pattern recognition receptors (PRRs) on macrophages recognize pathogen-associated molecular patterns and damage-associated molecular patterns and subsequently cause overproduction of proinflammatory cytokines and recruit adaptive immunity. Some biomarkers, such as ferritin and gasdermin D, reflecting macrophage activation were elevated and correlated with AOSD activity. Given that macrophage activation with the overproduction of proinflammatory cytokines plays a pathogenic role in AOSD, these inflammatory mediators would be the therapeutic targets. Accordingly, the inhibitors to interleukin- (IL-) 1, IL-6, and IL-18 have been shown to be effective in AOSD treatment. Gaining insights into the pathogenic role of macrophages in AOSD can aid in identifying disease biomarkers and therapeutic agents for this disease.

Adult Onset Still's Disease: A Retrospective, Single-Center Study

Background

Adult-onset Still's disease (AOSD) is characterized by a classical triad of spiking fever, arthritis, and evanescent rash. It is one of the main causes of hospital admissions for fever of unknown origin and has an extended mean time to diagnosis. Therefore, it remains underdiagnosed relative to its aforementioned time frame. In this study, we attempt to highlight clinical and lab findings associated with AOSD. We then compare our diagnostic results with similar previous studies. Our results should help physicians not to miss this rare entity and make the diagnosis in a reduced time frame.

Materials and methods

This a retrospective, single-center study conducted at Dow University Hospital in Karachi, Pakistan. Thirty patients were enrolled in this study for six months (July 2019-December 2019). All patients were identified and recruited in the medical outpatient department using Yamaguchi's criteria. Written consent was obtained from all patients to access all their clinical charts. Demographics and prior results of laboratory investigations were retrieved from the chart files.

Results

In our study, the mean age of patients was 26.6 years. More specifically, males accounted for 53.3% (n=16) of cases, and females accounted for 46.6% (n=14) of total cases. The most common presenting clinical features included arthralgia (100%, n=30), fever (100%, n=30), myalgia (96.6%, n=29), large joint arthritis (66.6%, n=20), sore throat (50%, n=15), hepatomegaly (40%, n=12), splenomegaly (23.3%, n=7), skin rash (36.6%, n=11) and pericarditis (20%, n=6). Furthermore, none of our patients had cervical lymphadenopathy. The most commonly reported laboratory findings include leukocytosis (100%, n=30), hyperferritinemia (90%, n=27), elevated erythrocyte sedimentation rate (100%, n=30) and abnormal liver function tests (76.6%, n=23). Chest x-rays performed in all patients revealed no abnormalities in 83% of patients (n=25). All patients in our study sample (n=30) tested negative for antinuclear antibodies and rheumatoid factor. It was also noted that the mean duration of diagnosis in our patients was 5.98 weeks. The mean hospitalization period in our patients was 12.5 days. Furthermore, 16.7% of patients (n=5) suffered from disease relapse. 

Conclusion

Our study ascertains that the presence of certain clinical and laboratory findings strongly indicate a diagnosis of adult-onset Still's disease.

Diagnostic Value of Common Inflammatory Markers on Fever of Unknown Origin

This study was designed to evaluate the diagnostic value of common inflammatory markers with regard to fever of unknown origin (FUO). We investigated 383 patients who were hospitalized with FUO at the Henan Province People's hospital between January 2009 and June 2015. Of all the cases, infectious diseases accounted for 33.9%, neoplasms for 21.1%, collagen vascular diseases for 25.1%, miscellaneous diseases for 4.7%, and no diagnosis for 15.1%. Patients in the neoplasm group were older than those in the infectious disease, collagen vascular disease, and miscellaneous disease groups (p = 0.006, p < 0.0001, and p = 0.001, respectively). The duration of fever before admission of patients in the neoplasm and collagen vascular disease group was longer than that of patients in the infectious disease group (p = 0.002 and p = 0.007, respectively). The diagnostic time after admission of patients from the neoplasm and collagen vascular disease groups was longer than that for patients from the infectious disease group (both p < 0.0001). Serum ferritin levels of patients in the infectious disease group were lower than those of patients in the neoplasm and collagen vascular disease groups (p = 0.029 and p = 0.032, respectively), while serum procalcitonin (PCT) levels in the infectious disease group was higher than that in the neoplasm and collagen vascular disease groups (p = 0.016 and p = 0.007, respectively). Therefore, FUO remains a clinical problem in China and serum ferritin and PCT may be useful in discriminating infectious from non-infectious causes (neoplasms and collagen vascular diseases) in patients with FUO.

Recurrent fever of unknown origin (FUO): aseptic meningitis, hepatosplenomegaly, pericarditis and a double quotidian fever due to juvenile rheumatoid arthritis (JRA)

BACKGROUND

Fever of unknown origin (FUO) has been defined as a fever of ≥101°F that persists for 3 weeks or more. It is not readily diagnosed after 1 week of intensive in-hospital testing or after intensive outpatient or inpatient testing. Fevers of unknown origin may be caused by infectious diseases, malignancies, collagen vascular diseases, or a variety of miscellaneous disorders. The relative distribution of causes of FUOs is partly age-related. In the elderly, the preponderance of FUOs is attributable to neoplastic and infectious etiologies, whereas in children, collagen vascular diseases, neoplasms, and viral infectious disease predominate. The diagnostic approach to FUOs depends on a careful analysis of the history, physical findings, and laboratory tests. Most patients with FUOs exhibit localizing findings that should direct the diagnostic workup and limit diagnostic possibilities. The most perplexing causes of FUOs involve those without specific diagnostic tests, e.g., juvenile rheumatoid arthritis (JRA) or adult Still's disease. In a young adult with FUO, if all of the cardinal symptoms are present, JRA may present either a straightforward or an elusive diagnosis, if key findings are absent or if the diagnosis goes unsuspected.

METHODS

We present a 19-year-old man with a recurrent FUO. His illness began 3 years before admission and has recurred twice since. In the past, he did not manifest arthralgias, arthritis, or a truncal rash. On admission, he presented with an FUO with hepatosplenomegaly, aseptic meningitis, and pericarditis. An extensive diagnostic workup ruled out lymphoma and leukemia. Moreover, a further extensive workup eliminated infectious causes of FUO appropriate to his clinical presentation, ie, tuberculosis, histoplasmosis, brucellosis, Q fever, typhoid fever, Epstein-Barr virus, infectious mononucleosis, cytomegalovirus, human herpes virus (HHV)-6, babesiosis, ehrlichiosis, viral hepatitis, and Whipple's disease.

RESULTS

The diagnosis of JRA was based on the exclusion of infectious and neoplastic disorders in a young adult with hepatosplenomegaly, aseptic meningitis, pericarditis, and a double quotidian fever. With JRA, tests for rheumatic diseases are negative, as they were in this case. The only laboratory abnormalities in this patient included elevated serum transaminases, a mildly elevated erythrocyte sedimentation rate, and a moderately elevated level of serum ferritin.

CONCLUSION

Diagnostic fever curves are most helpful in cases where the diagnosis is most elusive, as was the case here. Relatively few disorders are associated with a double quotidian fever, ie, visceral leishmaniasis, mixed malarial infections, right-sided gonococcal acute bacterial endocarditis, and JRA. Because the patient received antipyretics during the first week of admission, fever was not present. After infectious disease consultation during week 2 of hospitalization, antipyretics were discontinued, and a double quotidian fever was present, which provided the key diagnostic clue in this case.