AB1069 CONSIDERATION OF YAO SYNDROME AS A DIFFERENTIAL DIAGNOSIS FOR HEREDITARY PERIODIC FEVER SYNDROMES

The expanding clinical spectrum of autoinflammatory diseases with NOD2 variants: a case series and literature review

Objective

To assess the impact conferred by NOD2 variants on the clinical spectrum of patients with systemic autoinflammatory diseases (SAIDs) in Greece.

Methods

Consecutive patients (n=167) with confirmed SAIDs who underwent screening by next generation sequencing (NGS) targeting 26 SAID-associated genes, and carried at least one NOD2 gene variant, were retrospectively studied. The demographic, clinical and laboratory parameters were recorded.

Results

In total, 24 rare NOD2 variants in 23/167 patients (14%) were detected. Notably, 18 patients had at least one co-existing variant in 13 genes other than NOD2. Nine patients had juvenile- and 14 adult-onset disease. All patients presented with symptoms potentially induced by the NOD2 variants. In particular, the candidate clinical diagnosis was Yao syndrome (YAOS) in 12 patients (7% of the whole SAID cohort). The clinical spectrum of patients with YAOS (mean episode duration 8 days) was fever (n=12/12), articular symptoms (n=8), gastrointestinal symptoms (n=7; abdominal pain/bloating in 7; diarrhea in 4; oral ulcers in 3), serositis (n=7), and rash (n=5), while the inflammatory markers were elevated in all but one patient. Most of these patients showed a poor response to nonsteroidal anti-inflammatory drugs (n=7/9), colchicine (n=6/8) and/or anti-TNF treatment (n=3/4), while a complete response was observed in 6/10 patients receiving steroids and 3/5 on anti-IL1 treatment. Another 8 patients were diagnosed with either FMF (n=6) or PFAPA syndrome (n=2) presenting with prominent diarrhea (n=7), oral ulcers (n=2), periorbital swelling and sicca-like symptoms (n=1), or maculopapular rash (n=1). One patient had a clinically undefined SAID, albeit characterized by oral ulcers and diarrhea. Finally, one patient presented with chronic relapsing urticaria with periorbital edema and inflammatory markers, and another one had a Crohn-like syndrome with good response to anti-IL-1 but refractory to anti-TNF treatment.

Conclusion

NOD2 variants were detected in 1 out of 7 SAID patients and seem to have an impact on disease phenotype and treatment response. Further studies should validate combined molecular and clinical data to better understand these distinct nosological entities.

NOD2 Versus MEFV: Differential Diagnosis of Yao Syndrome and Familial Mediterranean Fever

OBJECTIVES

Yao syndrome (YAOS, OMIM 617321) was formerly designated as nucleotide-binding oligomerization domain-containing protein-2 (NOD2)-associated autoinflammatory disease (NAID). This disorder shares similar clinical phenotypes with hereditary periodic fever syndromes (HPFS). This study aimed to compare YAOS with familial Mediterranean fever (FMF).

METHODS

In this retrospective study, electronic medical records of a case series of YAOS were reviewed and data were analyzed. All patients underwent genetic testing for periodic fever syndrome 6-gene panel.

RESULTS

A total of 6 cases were presented. These patients were initially thought to have MEditerranean FeVer (MEFV)-negative FMF and received treatment with colchicine. They were eventually diagnosed with YAOS. The differences between these diseases were illustrated. In addition, both MEFV and NOD2 mutations were detected in some patients and family members. Patients with carriage of both gene mutations may present with heterogeneous disease expression. A close correlation between phenotypes and genotypes is needed to make a diagnosis.

CONCLUSIONS

YAOS may mimic FMF. Molecular analysis should cover NOD2 whole gene sequencing to help distinguish these diseases. Both NOD2 and MEFV mutations may contribute to disease expression in an individual.