fetching data ... 
Background: Gout is one of the most common inflammatory joint diseases [1]. As reported, gout can be categorized as early-onset gout (defined as the onset of symptoms before the age of 40 years) and late-onset gout (onset of symptoms at age ≥40 years), and the incidence of early-onset gout is increasing [2, 3]. Nevertheless, the exact pathogenesis of gout has not yet been completely elucidated and cannot be fully explained by the innate immune response.
Objectives: The present study compared the percentage and absolute counts of lymphocyte and CD4+T cell subsets in the peripheral blood of early-onset gout and late-onset gout patients with active gout attack and healthy controls (HCs). By comparing the levels of lymphocyte and CD4+T cell subsets, we aimed to elucidate the differences in adaptive immune cell phenotypes of early-onset gout and late-onset gout, and provide a basis for further exploration of their precise treatment.
Methods: This study involved 126 gout patients with active gout attack (53 patients with early-onset gout and 73 patients with late-onset gout) who were hospitalized at the Second Hospital of Shanxi Medical University, and 77 age- and gender-matched HCs. We detected the levels of lymphocyte and CD4+T cell subsets in peripheral blood by flow cytometry.
By comparing peripheral lymphocyte subsets between patients with early-onset gout and late-onset gout and HCs, we found that the absolute counts of T, B, CD4+T and CD8+T cells were higher in two gout groups than in HCs, and were higher in the early-onset gout group than in the late-onset gout group. The absolute counts of NK cells were lower in two gout groups than in HCs, yet there was no significant difference in NK cell levels of the two gout groups.
For the comparison of CD4+T cell subsets (Th1, Th2, Th17 and Treg cells) among early-onset gout group, late-onset gout group and HCs, the early-onset gout group was found to have elevated absolute counts of Th1 and Th17 cells, decreased percentage of Treg cells, and elevated Th17/Treg ratios compared to HCs. The late-onset gout group had a decreased percentage of Treg cells and an elevated Th17/Treg ratio compared to HCs. Furthermore, the absolute counts of Th2 and Th17 cells were higher in the early-onset gout group than in the late-onset gout group. However, there was no significant difference in absolute counts of Th1 and Treg cells and Th17/Treg ratio between the two gout groups.
Conclusion: Our results suggested that Th17/Treg imbalance during active gout attack differs between patients with early-onset gout and late-onset gout. Elevated Th17/Treg ratio in early-onset gout is mainly associated with increased Th17 cells, whereas elevated Th17/Treg ratio in late-onset gout is associated with decreased Treg cells. Thus, the characteristic differences in Th17/Treg imbalance between early-onset gout and late-onset gout during active gout attack indicate that the therapeutic focus of early-onset gout and late-onset gout should be different.
REFERENCES: [1] Jatuworapruk K, Grainger R, Dalbeth N, Taylor WJ. Development of a prediction model for inpatient gout flares in people with comorbid gout. Ann Rheum Dis 2020;79:418-23.
[2] Onuora S. ABCG2 SNP associated with early-onset gout. Nat Rev Rheumatol 2020;16:186.
[3] Zaidi F, Narang RK, Phipps-Green A, Gamble GG, Tausche AK, So A, et al. Systematic genetic analysis of early-onset gout: ABCG2 is the only associated locus. Rheumatology (Oxford) 2020;59:2544-9.
Comparison of percentage and absolute counts of lymphocyte and CD4+T cell subsets in the peripheral blood among patients with Early-onset gout (n=53), patients with Late-onset gout (n=73) and healthy controls (HCs, n=77). (*p<0.05, **p<0.001, ***p<0.0001)
* Correspondence: Caihong Wang. The Second Hospital of Shanxi Medical University, No. 382 Wuyi Road, Xinghualing District, 030000 Taiyuan, Shanxi, China. E-mail: snwch@sina.com
Acknowledgements: NIL.
Disclosure of Interests: None declared.