HLA-DQB1 DPB1 alleles in Japanese patients with adult-onset Still's disease

The Expanding Spectrum of Autoinflammatory Diseases

Autoinflammatory diseases are systemic disorders caused by genetic or acquired abnormalities in certain signaling pathways of the innate immune system. Dysregulated activation of the inflammasome, i.e. molecular platforms responsible for the activation of caspase-1 and production of interleukin-1β, causes autoinflammation. Familial Mediterranean fever (FMF), the most common genetic autoinflammatory disease, is characterized by a periodic fever and serositis. The complex and heterogeneous genetic background of Japanese FMF patients, accompanied by potential overlap with other rheumatic diseases, suggests crosstalk between genetic and environmental factors. Recently, FMF has been recognized as being part of a spectrum of autoinflammatory syndromes named pyrin-associated autoinflammatory diseases. The discovery of a new monogenic autoinflammatory disease, A20 haploinsufficiency, may provide novel insights into early-onset Behçet's-like diseases. In contrast, adult-onset Still's disease and Schnitzler's syndrome are acquired autoinflammatory diseases without a monogenic abnormality. Although the concept of autoinflammatory diseases originally applied to monogenic hereditary recurrent fevers, it has been expanded to include non-genetic complex autoinflammatory diseases. Information concerning monogenic autoinflammatory diseases may prove useful for elucidating the molecular mechanisms underlying non-genetic autoinflammatory diseases.

Refractory adult-onset Still's disease complicated with monoclonal gammopathy of undetermined significance: A case report

RATIONALE

Adult-onset Still's disease (AOSD) is a rare inflammatory disease characterized by a classic triad of daily spike fever, arthritis, and a typical salmon-pink rash. The involvement of inflammatory cytokines by various factors such as infection, drug, or neoplasm causes refractory AOSD.

PATIENT CONCERNS

We report a 63-year-old man with a high fever, rash, hyperferritinemia, and M proteinemia. His serum levels of interleukin-6 and interleukin-18 were remarkably high at 192 and 114,250 pg/mL, respectively.

DIAGNOSIS

AOSD complicated with monoclonal gammopathy of undetermined significance was diagnosed.

INTERVENTIONS

After steroid pulse therapy followed by oral prednisolone, cyclosporin, methotrexate, and colchicine, serum ferritin levels temporarily declined, but secondary cytomegalovirus infections exacerbated AOSD's activity.

OUTCOMES

Finally, after tocilizumab induction, AOSD activity was gradually suppressed over a long period.

LESSONS

The disease activity of AOSD is exacerbated by multiple factors, including comorbidities or infections. Clinicians need to consider that monoclonal gammopathy of undetermined significance complications might become AOSD refractory by an elevation of the inflammatory cytokines. Moreover, further prospective studies are required to confirm this result.

The Expanding Spectrum of Autoinflammatory Diseases

Autoinflammatory diseases are systemic disorders caused by genetic or acquired abnormalities in certain signaling pathways of the innate immune system. Dysregulated activation of the inflammasome, i.e. molecular platforms responsible for the activation of caspase-1 and production of interleukin-1β, causes autoinflammation. Familial Mediterranean fever (FMF), the most common genetic autoinflammatory disease, is characterized by a periodic fever and serositis. The complex and heterogeneous genetic background of Japanese FMF patients, accompanied by potential overlap with other rheumatic diseases, suggests crosstalk between genetic and environmental factors. Recently, FMF has been recognized as being part of a spectrum of autoinflammatory syndromes named pyrin-associated autoinflammatory diseases. The discovery of a new monogenic autoinflammatory disease, A20 haploinsufficiency, may provide novel insights into early-onset Behçet's-like diseases. In contrast, adult-onset Still's disease and Schnitzler's syndrome are acquired autoinflammatory diseases without a monogenic abnormality. Although the concept of autoinflammatory diseases originally applied to monogenic hereditary recurrent fevers, it has been expanded to include non-genetic complex autoinflammatory diseases. Information concerning monogenic autoinflammatory diseases may prove useful for elucidating the molecular mechanisms underlying non-genetic autoinflammatory diseases.

The clinical heterogeneity of adult onset Still's disease may underlie different pathogenic mechanisms. Implications for a personalised therapeutic management of these patients

Adult-onset Still's disease (AOSD) is a rare inflammatory disease of unknown aetiology usually affecting young adults and manifesting with a clinical triad of spiking fever, arthritis, and evanescent cutaneous rash. AOSD may be considered a highly heterogeneous disease, despite a similar clinical presentation, the disease course may be completely different. Some patients may have a single episode of the disease whereas others may evolve toward a chronic course and experience life-threatening complications. On these bases, to dissect the clinical heterogeneity of this disease, four different subsets were identified combining the manifestations at the beginning with possible diverse outcomes over time. Each one of these derived subsets would be characterised by a prominent different clinical feature from others, thus proposing dissimilar underlying pathogenic mechanisms, at least partially. Consequently, a distinct management of AOSD may be suggested to appropriately tailor the therapeutic strategy to these patients, according to principles of the precision medicine. These findings would also provide the rationale to recognise a different genetic and molecular profile of patients with AOSD. Taking together these findings, the basis for a precision medicine approach may be suggested in AOSD, which would drive a tailored therapeutic approach in these patients. A better patient stratification may also help in arranging specific designed studies to improve the management of patients with AOSD. Behind these different clinical phenotypes, distinct endotypes of AOSD may be suggested, probably differing in pathogenesis, outcomes, and response to therapies.

Serum VEGF-C as an evaluation marker of disease activity in adult-onset Still's disease

In view of the possible involvement of vascular endothelial growth factor-C (VEGF-C) in pathogenesis of adult-onset Still's disease (AOSD) based on our previous genome-wide association study (GWAS) results, the primary objective of this study, therefore, was to investigate the correlations between the content of VEGF-C in serum and clinical and biochemical markers of AOSD. Blood samples were collected from 80 patients with AOSD, 26 with rheumatoid arthritis (RA), 30 with systemic lupus erythematosus (SLE) and 31 healthy control subjects. The serum VEGF-C levels were determined using an enzyme-linked immunosorbent assay (ELISA). Statistical analysis and comparisons were conducted. A significantly higher serum VEGF-C level was observed in patients with AOSD than in HC. Serum VEGF-C levels had high AUC value of 0.8145 for distinguishing AOSD group from healthy group with sensitivity of 0.7097 and specificity of 0.8250. It also showed good diagnostic value to differentiate AOSD from other autoinflammatory diseases with sensitivity of 0.7500 and specificity of 0.5500. AOSD patients with fever, arthralgia, skin rash, sore throat, lymphadenopathy, splenomegaly hepatomegaly and pleuritis, had a higher level than those who did not have these symptoms (p = 0.0012, p = 0.0092, p = 0.0056, p = 0.0123, p = 0.0068, p = 0.0030, p = 0.0020, and p = 0.0018, respectively). The serum VEGF-C levels were also positively correlated with laboratory features and several cytokines related to AOSD disease activity. In conclusion, our study unveiled a close association between serum VEGF-C levels and AOSD including disease activity and clinical hematological manifestations, suggesting the potential utility of VEGF-C as a candidate biomarker to assess disease activity in AOSD.

Key diagnostic characteristics of fever of unknown origin in Japanese patients: a prospective multicentre study

OBJECTIVE

To identify the key diagnostic features and causes of fever of unknown origin (FUO) in Japanese patients.

DESIGN

Multicentre prospective study.

SETTING

Sixteen hospitals affiliated with the Japanese Society of Hospital General Medicine, covering the East and West regions of Japan.

PARTICIPANTS

Patient aged ≥20 years diagnosed with classic FUO (axillary temperature≥38.0°C at least twice within a 3-week period, cause unknown after three outpatient visits or 3 days of hospitalisation). A total of 141 cases met the criteria and were recruited from January 2016 to December 2017.

INTERVENTION

Japanese standard diagnostic examinations.

OUTCOME MEASURES

Data collected include usual biochemical blood tests, inflammatory markers (erythrocyte sedimentation rate (ESR), C reactive (CRP) protein level, procalcitonin level), imaging results, autopsy findings (if performed) and final diagnosis.

RESULTS

The most frequent age group was 65-79 years old (mean: 58.6±9.1 years). The most frequent cause of FUO was non-infectious inflammatory disease. After a 6-month follow-up period, 21.3% of cases remained undiagnosed. The types of diseases causing FUO were significantly correlated with age and prognosis. Between patients with and without a final diagnosis, there was no difference in CRP level between patients with and without a final diagnosis (p=0.121). A significant difference in diagnosis of a causative disease was found between patients who did or did not receive an ESR test (p=0.041). Of the 35 patients with an abnormal ESR value, 28 (80%) had causative disease identified.

CONCLUSIONS

Age may be a key factor in the differential diagnosis of FUO; the ESR test may be of value in the FUO evaluation process. These results may provide clinicians with insight into the management of FUO to allow adequate treatment according to the cause of the disease.