关键词: 痛风, 中性粒细胞/淋巴细胞, 痛风间歇期, 尿酸排泄分数

Abstract: Background　As the most common form of inflammatory arthritis，the morbidity of gout is gradually increasing，and its occurrence is closely related to hyperuricemia.Uric acid is mainly excreted by kidney.The current indicators to evaluate the level of uric acid excretion by kidney mainly include 24-hour urinary uric acid，clearance rate of uric acid and creatinine，fractional excretion of uric acid （FEUA） and urinary uric acid/urinary creatinine.FEUA is an indicator can reflect renal excretion more accurately.Objective　To investigate the changes of neutrophil/lymphocyte ratio （NLR） in gout patients during the intercritical period and FEUA staging，and to analyze whether it can provide a new reference index for FEUA staging.Methods　A total of 386 gout patients in intermittent phase who were treated in the outpatient and inpatient departments of the Affiliated Hospital of North Sichuan Medical College from December 2013 to July 2019 were selected，and 154 healthy persons matched with age and gender were selected.206 gout patients in intermittent phase who completed the 24-hour Urinalysis were treated as the gout group，and 39 of the 154 healthy persons who completed the 24-hour Urinalysis were treated as the control group.Gout group was classified according to the level of FEUA：FEUA<7% was the excretion-decreased type，FEUA 7%-12% was the mixed type，and FEUA>12% was the synthesis-increased type.The data of age，gender，height，body mass，smoking history，drinking，24-hour urine output，24-hour urinary uric acid，24-hour urine creatinine，blood uric acid （UA），creatinine clearance rate （Cr），FEUA，clearance rates of uric acid and creatinine，urinary uric acid/ creatinine，urinary pH，estimated glomerular filtration rate （eGFR） and the laboratory tests 〔including white blood cell count （WBC），neutrophil （GR），lymphocyte （LYM），platelet （PLT），average red blood cells （MCV）〕 in their first-time consultancy，the number of affected joints，the history situation of tophi，plateau living history，hypertension，diabetes，hyperlipidemia，kidney stones and family history of gout in different types of gout patients was collected.Results　BMI，smoking history ratio，drinking history ratio，24-hour urine output，UA，GR and NLR of the gout group were higher than the control group，and FEUA，uric acid clearance rate and eGFR of the gout group were lower than the control group （P<0.05）.NLR level was positively correlated with FEUA in gout patients（rs=0.242，P<0.05），negatively correlated with clearance rate of creatinine（rs=-0.150，P<0.05）.There were 206 subjects in the gout group，including 183 gout patients who had reduced uric acid excretion，15（7.3%） gout patients who had mixed type，and 8 （3.9%） gout patients who had increased uric acid excretion.There were significant differences in the proportion of drinking history，the proportion of renal stone，24-hour urine output，serum uric acid，serum creatinine，FUEA，uric acid clearance rate，creatinine clearance rate，uric acid/urinary creatinine，neutrophils and NLR maong different gout types patients （P<0.05）.Multivariate Logistic regression analysis showed that alcohol consumption，24-hour urine volume，serum uric acid，uric acid excretion fraction，eGFR and NLR were the influencing factors of gout occurrence （P < 0.05）.The area under the ROC curve （AUC） of NLR for the diagnosis of gout was 0.748 （0.674，0.822），the best cutoff value was 1.76，the sensitivity was 78.16%，and the specificity was 61.54%.The AUC of 95%CI of NLR for the diagnosis of excretion-decreased type was 0.739 （0.662，0.816），the best cutoff value was 1.76，the sensitivity was 77.60%，the specificity was 61.54%.The AUC 95%CI of NLR in the diagnosis of mixed gout was 0.758 （0.601，0.915），the best cutoff value was 3.54，the sensitivity was 50.00%，the specificity was 100.00%.The AUC 95%CI of NLR for the diagnosis of synthesis-increased type was 0.936 （0.844，1.000），the best cutoff value was 4.07，the sensitivity was 75.00%，and the specificity was 100.00%.Conclusion　NLR is closely related to the occurrence of gout，and it has important value in the staging of FEUA.It can guide contrapuntally selection of anti-uric acid drugs in clinical medication.

Key words: Gout, Neutrophil/lymphocyte ratio, Intercritical gout, Fractional excretion of uric acid