Objective To promote preventive and therapeutic measures for osteoporosis by investigating the prevalence of low bone mineral density (BMD) in connective tissue disease patients who were taking corticosteroid and identify the associated risk factors of osteoporosis.Methods Thirty-eight female patients who had connective tissue diseases and were taking corticosteroid in PU MCH rheumatology outpatient clinic were studied and followed up from Oct 2006 to April 2007.Lumber spine and right femoral bone mineral density were determined bv dual energy X ray absortiometry (DEXA).Clinical information was obtained from a questionnaire of history and medical records.Duration and accumulative dosage of glucocorticoid intaking.menopause time were obtained retrospectively.Correlation analysis between BMD and clinical information was conducted.Results ① In 38 patients,23 (61%) patients showed a normal BMD,10 (26%) were osteopenia,3 (8%) were iu the osteoporotic range,while 2 patienLs (53%) had fragile fracture.② Compared with patients with normal BMD,subjects with low BMD had significantly older age,longer period after menopause and higher accumulated dose of corticosteroids.③ Postmenopausal women had significantly lower BMD in lumber and hip than premenopausal women.④ Either of vertebral and right hip BMD correlated negatively with the accumulated dosage of cortieosteroids by simple linear regression.⑤ The correlation between BMD and accumulated dosage of corticosteroids improved after correcting for the effect of age by partial correlation analysis (Pearson partial vertebral r=-0.8,P=0.009;right hip r=-0.3,P=0.010).⑥ A stepwise multivariate linear regression model was constructed to explore the relationship between the different clinicsl factors studied and a low BMD.Two statistically significant variables were menopause status (P=0.0000) and a higher steroid accumulated dosage (P=0.008).Conclusion Low BMD is common in connective tissue disease patients receiving corticosteroid.Risk factors for low BMD are postmenopause.duration and the accumulated dosage of glucocorticosteroid.The high prevalence of low BMD implies that more attention should be paid to the prevention and treatment of osteoporosis and fractures in connective tissue disease patients who are taking corticosteroids.

SUMMARY Here we reported two patients who presented with panuveitis and were transferred from oph-thalmologists to rheumatologists,for both the patients had oral and genital ulcers.They were misdiag-nosed with Behcet’s disease at first glance.Two young males presented with acute uveitis with history of recurrent oral and genital ulcers.They initially presented with symptoms and signs resembling Behcet’s disease and were treated with systemic steroids with suboptimal responses.Routine laboratory test re-vealed syphilis and human immunodeficiency virus (HIV)infection.After treatment of penicillin and anti HIV virus therapy,the panuveitis was relived.The other patient was lost in the follow up.Recently epi-demiological data indicate that syphilis and HIV infection increase,which can mimic the manifestation of Behcet’s disease.Diagnosis of sexual transmitted diseases,such as HIV or syphilis needs to be ruled out in all cases that mimic the clinical feature of Behcet’s disease,especially for those who had a history of high risk behaviors.Every patient should have history analysis in detail.Screening of sexual transmitted diseases,such as HIV or syphilis is important especially in those rapid progressive panuveitis.Also, other virus infections,such as cytomegalovirus,epstein-barr virus or Herpes simplex virus can cause mucosa ulcers and uveitis.CD4 T cell count is a very important marker to indicate that the patient has immunodeficiency.Erythema nodosa and pseudofolliculitis are the third common clinical manifestation in Chinese Behcet’s disease patients.Rheumatologist should watch out for patients without skin involvement when making the diagnosis of Behcet’s disease.Syphilis-associated uveitis usually has a good prognosis. Treatment of antibiotics can get good response,92% uveitis can be relieved,with 67% improved vision. Acute syphilitic posterior placoid chorioretinitis (ASPPC)is a clinically and angiographically distinct manifestation of ocular syphilis.Systemic glucocorticoid can be used in syphilis induced posterior uveitis, sleritis and optic neuritis,and it can also prevent the Hector’s reaction.However,for patients diagnosed with both HIV and syphilis,regular antibiotic can not prevent relapse.So doctors need to follow up them regularly.Patients who present with uveitis,oral and genital ulcers can be easily diagnosed with Behcet’s disease.Rheumatologists need to be aware of the reemergence of sexual transmitted disease.High degree of clinical suspicion can allow ophthalmologists and rheumatologists to diagnose and treat the disease ear-ly.Correct diagnoses timely can get the good treatment response,and rescue the vision.Treatment with regular antivirus and Penicillin can receive the good response,and moreover glucocorticoid can relieve the inflammation.

SUMMARY A 36-year-old woman had an 8-year history of systemic lupus erythematosus (SLE) and was being treated with 10 mg/d of prednisone.She presented with a 6-month history of intermittent fever and multiple painful multi skin erythematous macules in her button, hips and extremities that had slowly en-larged to 8 cm ×4 cm in diameter.The lesions started as painful erythematous macules, which eventually ulcerated and scared.Laboratory tests showed leukopenia, protenuria, positive anti-double strand DNA and hypocomplementemia.Cultures of the bottom ulcer were E.Coli, fugus and Tuberculous mycobacteria were both negative.Biopsy was performed and revealed necrosis of epidermis, thrombus and cellulose de-generation in epidermis with neutrophils karyorrhexis and vasculitis.Her SLE was active, so she was pre-scribed antibiotics for 2 weeks and prednisone was added to 60 mg/d for a month.However her skin ul-cers did not relieve.When prednisone was added to 120 mg/d with combination therapy of cyclophospha-mide and hydroxychloroquine, her skin ulcer cicatrized gradually.

Objective:To find the correlation of wrist bone mineral density ( BMD ) to wrist synovitis and erosion , by comparing wrist BMD and ultrasonography .Methods: A number of 80 female RA pa-tients were examined by BMD measurement of the femoral neck , spine and non-dominant wrist using du-al-energy X-ray absorptiometry ( DXA ) .Synovitis of the wrist was examined by ultrasonography .The wrist joint ( radiocarpal joint , dorsal midline , and carpoulnar joint ) was assessed in the same side of DXA, with transverse and longitudinal scans for USGS synovial hypertrophy and proliferation , tenosynovi-tis,tendinitis and bone erosion .Colour and power doppler ultrasonography ( PDUS) were used to sum the synovitis score .Results:We found:( 1 ) In the study , 80 female RA patients were enrolled , the mean age was 54.6 ±13.3 (27.0-80.0) years, the disease duration was 48 (12-116) months, and the body Mass Index was 23.0 ±4.0 (14.8-31.2) kg/m2 .The Wrist BMD ( g/cm2 ) in RA significantly reduced, compared with normal controls (0.297 ±0.121 vs.0.420 ±0.180,P<0.01).(2) The Wrist BMD (g/cm2) exceeded in early RA compared with the established RA (0.326 ±0.103 vs.0.285 ± 0 .132 ,P<0 .01 );the positive rate of severe osteoporosis in wrist was lower in early RA compared with the established RA(47.8%vs.64.9%, P<0.05); the positive rate of bone erosion in wrist by ultra-sound was lower in early RA compared with the established RA (39.1%vs.56.1%, P<0.01).(3) The wrist BMD ( g/cm2 ) in RA with high disease activity reduced compared with moderate and low disease activity (0.267 ±0.140 vs.0.280 ±0.126) and (0.267 ±0.140 vs.0.320 ±0.103) respec-tively , P<0 .05 ) .The percentages of positive ACPA in the high and moderate disease activity groups were significantly higher than those in the remission group (85% vs.81.8% and 92.6% vs.81.8%, respectively).DAS28ESR was correlated with wrist BMD (r=-0.288, P<0.01).(4) A significant positive correlation was found between wrist and spine /femur BMD ( r=0.634, P<0.01, r=0.795, P<0.01), and a negative correlation between wrist and disease duration and DAS 28ESR (r=-0.286, r=-0.301,P<0.01).There was a highly significant positive correlation between wrist BMD and femur BMD (r=0.95,P<0.05).(5) RA patients in wrist osteoporosis group had higher RF positive rate and ACPA rate than wrist osteopenia group (75.5%vs.55.6%,P<0.05,100% vs.83.3%, P<0.05). The patients of BMD osteoporosis group had higher DAS 28ESR compared with osteopenia group (5.3 ± 1.8 vs.3.7 ±1.5, P<0.01).The percentages of synovitis (61.5%vs.51.7%, P<0.05), tendeni-tis (14.3%vs.10.0%, P<0.05) and bone erosion (54.2%vs.46.2%, P<0.05) in wrist by ultra-sonography in osteoporosis group were higher than those of osteopenia group .(6) The wrist BMD in ne-gative bone erosion group by ultrasonography was lower than that in positive bone erosion group [ (0.333 ± 0.107) g/cm2 vs.(0.264 ±0.125) g/cm2, P<0.01], also the PDUS score was higher than positive bone erosion group (4.53 ±1.40 vs.2.55 ±2.66,P<0.01).Compared with negative bone erosion group, the patients in positive bone erosion group had longer disease duration (96.0 ±104.7) months vs.(66.2 ±78.0) months, P<0.05), higher percentage of RF (81.0% vs.53.8%,P<0.01), ACPA (92.7%vs.79.5%, P<0.05).and higher DAS28ESR (5.4 ±1.8 vs.4.2 ±2.0,P<0.05). The percentage of wrist synovitis in positive bone erosion group was higher (75.6% vs.30.8%,P<0.01) than that of negative bone erosion group , and moreover , the percentage of severe osteoporosis in the wrist was significantly higher (75.0%vs.46.4%, P<0.01).(7) A stepwise multivariate linear regression model was constructed to explore the relationship between the different clinical factors studied and a low wrist BMD.Statistically significant variables were age (P=0.001), disease duration (P=0.017), DAS28ESR (P=0.021), and ACPA (P=0.05).Conclusion:This study shows a highly sig-nificant correlation between hand BMD with disease duration and disease activity , and female RA patients with high titer of ACPA have lower wrist BMD .ABSTRACT Objective:To find the correlation of wrist bone mineral density ( BMD ) to wrist synovitis and erosion , by comparing wrist BMD and ultrasonography .Methods: A number of 80 female RA pa-tients were examined by BMD measurement of the femoral neck , spine and non-dominant wrist using du-al-energy X-ray absorptiometry ( DXA ) .Synovitis of the wrist was examined by ultrasonography .The wrist joint ( radiocarpal joint , dorsal midline , and carpoulnar joint ) was assessed in the same side of DXA, with transverse and longitudinal scans for USGS synovial hypertrophy and proliferation , tenosynovi-tis,tendinitis and bone erosion .Colour and power doppler ultrasonography ( PDUS) were used to sum the synovitis score .Results:We found:( 1 ) In the study , 80 female RA patients were enrolled , the mean age was 54.6 ±13.3 (27.0-80.0) years, the disease duration was 48 (12-116) months, and the body Mass Index was 23.0 ±4.0 (14.8-31.2) kg/m2 .The Wrist BMD ( g/cm2 ) in RA significantly reduced, compared with normal controls (0.297 ±0.121 vs.0.420 ±0.180,P<0.01).(2) The Wrist BMD (g/cm2) exceeded in early RA compared with the established RA (0.326 ±0.103 vs.0.285 ± 0 .132 ,P<0 .01 );the positive rate of severe osteoporosis in wrist was lower in early RA compared with the established RA(47.8%vs.64.9%, P<0.05); the positive rate of bone erosion in wrist by ultra-sound was lower in early RA compared with the established RA (39.1%vs.56.1%, P<0.01).(3) The wrist BMD ( g/cm2 ) in RA with high disease activity reduced compared with moderate and low disease activity (0.267 ±0.140 vs.0.280 ±0.126) and (0.267 ±0.140 vs.0.320 ±0.103) respec-tively , P<0 .05 ) .The percentages of positive ACPA in the high and moderate disease activity groups were significantly higher than those in the remission group (85% vs.81.8% and 92.6% vs.81.8%, respectively).DAS28ESR was correlated with wrist BMD (r=-0.288, P<0.01).(4) A significant positive correlation was found between wrist and spine /femur BMD ( r=0.634, P<0.01, r=0.795, P<0.01), and a negative correlation between wrist and disease duration and DAS 28ESR (r=-0.286, r=-0.301,P<0.01).There was a highly significant positive correlation between wrist BMD and femur BMD (r=0.95,P<0.05).(5) RA patients in wrist osteoporosis group had higher RF positive rate and ACPA rate than wrist osteopenia group (75.5%vs.55.6%,P<0.05,100% vs.83.3%, P<0.05). The patients of BMD osteoporosis group had higher DAS 28ESR compared with osteopenia group (5.3 ± 1.8 vs.3.7 ±1.5, P<0.01).The percentages of synovitis (61.5%vs.51.7%, P<0.05), tendeni-tis (14.3%vs.10.0%, P<0.05) and bone erosion (54.2%vs.46.2%, P<0.05) in wrist by ultra-sonography in osteoporosis group were higher than those of osteopenia group .(6) The wrist BMD in ne-gative bone erosion group by ultrasonography was lower than that in positive bone erosion group [ (0.333 ± 0.107) g/cm2 vs.(0.264 ±0.125) g/cm2, P<0.01], also the PDUS score was higher than positive bone erosion group (4.53 ±1.40 vs.2.55 ±2.66,P<0.01).Compared with negative bone erosion group, the patients in positive bone erosion group had longer disease duration (96.0 ±104.7) months vs.(66.2 ±78.0) months, P<0.05), higher percentage of RF (81.0% vs.53.8%,P<0.01), ACPA (92.7%vs.79.5%, P<0.05).and higher DAS28ESR (5.4 ±1.8 vs.4.2 ±2.0,P<0.05). The percentage of wrist synovitis in positive bone erosion group was higher (75.6% vs.30.8%,P<0.01) than that of negative bone erosion group , and moreover , the percentage of severe osteoporosis in the wrist was significantly higher (75.0%vs.46.4%, P<0.01).(7) A stepwise multivariate linear regression model was constructed to explore the relationship between the different clinical factors studied and a low wrist BMD.Statistically significant variables were age (P=0.001), disease duration (P=0.017), DAS28ESR (P=0.021), and ACPA (P=0.05).Conclusion:This study shows a highly sig-nificant correlation between hand BMD with disease duration and disease activity , and female RA patients with high titer of ACPA have lower wrist BMD .

Objective:To verify the fracture risk assessment tool ( FRAX) to estimate the probability of osteoporotic fracture in patients with rheumatoid arthritis ( RA ) with or without bone mineral density (BMD), and identify associated risk factors of osteoporosis .Methods: In the study, 200 patients with rheumatoid arthritis aged more than 40 years in Peking University First Hospital from Dec .2009 to Dec. 2012 were recruited.Clinical information was obtained from a questionnaire of their case history and medical records.FRAX tool was administered.Their lumber spine and left femoral BMD were determined by dual energy X ray absorptiometry.The gender, age, disease duration, menopause status, body mass index ( BMI) and accumulative dose of glucocorticoid were obtained in retrospect .Correlation analysis was conducted between the BMD and clinical information .Results:The study population ( female, 77.5%) had a mean age of 59.4 years, in which 10 (13%) patients showed a normal BMD, 67 (87%) were osteopenia or osteoporosis , while 32 patients (16%) had fragile fracture.Compared with the patients with normal BMD, the subjects with low BMD had significantly older age , longer period for corticoids usage , higher day dose and accumulated dose of corticoids .The 10-year fracture risk of sustai-ning major osteoporotic fractures and hip fracture was higher .No significant difference was observed be-tween the 10-year fracture risks calculated with BMD and without BMD .The values of the different area under the receiver operating characteristic ( ROC) curve ( AUC) for major and hip fractures calculated in three ways:without BMD, with the femoral neck BMD, and with T-score.The best result was for FRAX tool for hip fracture with the T-score ( AUC 0 .899 ) .A stepwise multivariate linear regression model was constructed to explore the relationship between the different clinical factors studied and a low BMD . Three statistically significant variables for lumber BMD were pain on visual assessment scale ( VAS ) (P=0.02), fracture history (P=0.003) and a higher steroid accumulated dose (P=0.008).Three statistically significant variables for left hip BMD were age (P<0.001), fracture history (P=0.05) and lower BMI ( P=0.03) .Conclusion:Low BMD is a common complication in RA patients .Risk factors for major fracture and hip fracture are increased .There is a positive correlation between FRAX calculated with and without BMD or T score .FRAX with the femoral neck T score or BMD presents a discriminatory capacity better than FRAX without BMD , according to the AUC ROC .

BACKGROUND: Pedicle screws are widely used in spinal internal fixation, while complications related to screw mistaken placement can be found occasionally. Conventional imaging examination cannot provide the accurate situation of the nail, and the nail path can be directly revealed on CT.OBJECTIVE: To discuss the application of CT scanning in the preoperative planning of lumbar spine surgery using digital technology.METHODS: 136 patients were enrolled, and digital technology was used to determine the best nailing track on planar CT images. Then the length of the pedicle screws, width of the pedicle, angle between pedicle screws and standard sagittal plane, and angle between pedicle screw and spinous process as well as sagittal plane were measured. The difference in measured values on each side was compared. Also, the difference in angle between pedicle screw and sagittal plane and spinous process was compared.RESULTS AND CONCLUSION: (1) There was no significant difference in the length of pedicle screw in both sides (P > 0.05). (2) There was significant difference in the width of pedicle screw at L1 and L4 of two sides (P < 0.05). (3) The angle between pedicle screw and standard sagittal plane at each level bilaterally did not differ significantly (P > 0.05). (4) The angle between pedicle screw and spinous process at each level bilaterally did not differ significantly (P > 0.05). (5) To conclude, pedicle CT scanning can accurately reflect patients' pedicle anatomic situation, which can help surgeons to design an appropriate scheme. Moreover, the anatomical variations of lumbar spine are remarkable, so pedicle screw insertion should be planned individuality.

Objective To investigate the outcomes of patients with rheumatoid arthritis (RA) treated by different combination of synthetic disease modifying antirheumatic drugs (DMARDs) under the guidance of treat-to-target strategy.Methods Forty-two RA patients with high disease activity were enrolled into this randomized,open-label and prospective study.It was comprised of a maximal 36-week induction phase and then followed by a maintenance phase up to 84 weeks.Combination of synthetic DMARDs was initiated in the induction phase,with or without low dose glucocorticoids (GCs) during the first 12 weeks.Patients who achieved low disease activity (LDA) were randomized into two maintenance groups.An increase of DAS28 by 0.6 was defined as relapse.The patients achieved LDA in the induction phase,relapsed during maintenance phase and possible relevant risk factors were analyzed.Results Twenty-seven (64％) patients achieved LDA during the induction phase.More non-smoking patients achieved LDA than those smoked [85％ (11/13) vs 55％(16/29),P＜0.05].During the maintenance phase,14 (61％) out of 27 patients relapsed.Patients taking GCs during the first 12 weeks had a significantly higher relapse rate compared to those without GC (83％ vs 36％,P=0.021).Patients who entered maintenance phase at week 12 had a significantly higher tendency to relapse compared to those who entered the maintenance phase at week 24 [75％(9/12) vs 33％(3/9),P=0.026].Conclusion Smoking seems to be a risk factor for RA patients who fail to reach LDA.Low dose GCs as a bridge therapy may require a longer duration.High relapse rates in both the maintenance groups indicat that a longer tight induction phase may be appropriate before downstairs therapy.

Objective To explore the impact of dyslipidemia on uric acid stones by analyzing the relationship between blood lipids and urolithiasis in primary gouty patients.Methods We retrospectively identified patients with nephrolithiasis in primary gout patients who underwent stone chemical analysis,compared with gout patients without nephrolithiasis.The clinical parameters,urine analysis and lipid levels were analyzed.Patients were divided into groups based on serum lipid levels.The groups were compared based on demographic data and stone composition.Correlations were analyzed between serum lipid,urinary pH and uric acid stones.Moreover,the risk factors of uric acid stones were determined by logistic regression analysis.Analysis of variance,t-test,chi-square test,Spearman's test and Logistic regression were used for statistical analysis.Results ① A total of 144 gout patients were included in study,48 patients with urolithiasis and 96 patients without urolithiasis.② Serum lipid levels were significantly lower in urolithiasis group than those patients without urolithiasis including triglyceride (TG) [1.6(0.9,2.1) mmol/L vs 2.2(1.4,3.2) mmol/L,Z=2.38,P=0.01],total cholesterol (TC) [(4.4±1.2) mmol/L vs (5.1±1.0) mmol/L,t=5.3,P=0.006];low density lipoprotein cholesterol (LDL-C) [(2.5±0.9) mmol/L vs (3.2±0.9) mmol/L,t=4.2,P=0.005].③ Compared to oxalate stone formers,uric acid stone formers had significantly higher TG [(1.8±0.6) mmol/L vs (0.9±0.5) mmol/L,t=4.9,P=0.001),TC [(4.4±1.1) mmol/L vs (3.8±1.0) mmol/L,t=1.8,P=0.001] and LDL-C [(2.8±0.9) mmol/L vs (2.0±0.7) mmol/L,t=3.5,P=0.045],while the high density lipoprotein (HDL) level was lower [(0.94±0.23) mmol/L vs (1.32±0.41) mmol/L,t=-4.0,P=0.002].④ Percentage of uric acid stones in high TG group was higher than normal TG group [85％(17/20 vs 46.4％(13/28),x2=7.4,P=0.007],in addition,the percentage of uric acid stones in low HDL group was higher than normal HDL group [(82.1％(23/28) vs 35.0％(7/20),x2=11.1,P=0.001].⑤ Uric acid stones were significantly correlated with high TG,low LDL and urinary pH(r=0.522,0.47,-0.212,respectively).Logistic analysis showed risk factors for uric acid stone in primary gouty patients were high TG [OR=2.38,95％CI(1.41,13.7);P=0.01] and lower HDL level [OR=0.01,95％CI(0.01,0.43);P=0.01].Conclusion There is a link between dyslipidemia and kidney uric acid stone risk in primary gout patients.Specific alterations in patient's lipid profile may portend unique aberrations in urine physico-chemistry and uric acid stone risk.

Objective To explore the risk factors of urate deposition on ultrasound in patients with gout.Methods All the gout patients who visited our center between February 2015 and February 2017 and underwent ultrasound examination of bilateral knees,ankles and first metatarsophalangeal joints (MTP1) were enrolled.Subgroup analysis was done depending on whether double contour sign (DCS) or tophus was found on ultrasound.Main statistical analysis methods were t test,chi-square test and logistic regression model.Results One hundred and twenty-six patients were included.DCS was found in 50(39.7％) patients and tophus was found in 48 (38.1％) patients.The serum uric acid (SU) level of the DCS positive group was signi-ficantly higher than the DCS negative group [(602±79) μmol/L vs (538±101) μmol/L,t=3.998,P=0.044].The hyperuicemia duration of the two groups were (186±87) months and (130±77) months,which was significantly different (t=3.330,P=0.002).The hyperuicemia duration of the tophus positive group was significantly higher than tophus negative group [(175±102) months vs (138±96) months,t=2.003,P=0.045].The SU level and hyperuicemia duration were independent risk factors of positive DCS in gout patients [OR =1.006,95％ CI (1.002,1.01 1);OR=1.028,95％CI (1.013,1.042)].The hyperuicemia duration was independent risk factor of positive tophus in gout patients [OR=1.004,95％CI (1.000,1.007)].Receiver operating characteristic curve (ROC) curve showed gout patient whose hyperuricemia duration was longer than 94months and SU level was higher than 505.5 μmol/L were more likely to have positive DCS in joints;meanwhile,patient whose hyperuricemia duration was longer than 137 months were more likely to have positive tophus in joints.Conclusion Gout patients who have positive DCS and tophus on ultrasound have longer hyperuicemia duration.Positive DCS is also related with patients' higher serum levels.The hyperuicemia duration is an independent risk factor of urate deposition on ultrasound in patients with gout.

Objective To explore the risk factors of urinary stone formation in primary gout patients by urinary chemical,serum and urinary biochemical features analysis.Methods All the patients diagnosed as primary gout at Peking University First Hospital from 2009 to 2015 were included in the study.All patients were diagnosed with or without urolithiasis by ultrasound or computed tomography.Their clinical features,baseline urinary metabolic panels and stone composition were analyzed and compared between the two group of patients.Moreover,the risk factors of uric acid stone formation were determined by comparing different composition of stone formation group.Analysis of variance,t-test,chi-square test,spearman's test and logistic regression were used for statistical analysis.Results One hundred and forty-four male gout patients were enrolled in the study among these patients,48 were with urolithiasis and 96 patients were without urolithiasis.Most (136,94.4％) patients were under excretion of uric acid.Among 48 gout patients with uric acid urolithiasis,30 (62.5％) patients who had pure uric acid stones,and 18 (37.5％) had stones composed of mixed uric acid and oxalic acid.Compared with mixed stone group,the mean age was significantly lower in pure uric acid stone group [(46±13) years vs (60±15) years,t=4.1,P＜0.05];and disease duration was shorter [(42±11)months vs (71±22) months,t=-0.2,P＜0.01].The 24-hour urinary uric acid were significantly higher in the uric acid stone group [(5 205±3 524) μmol/d vs (2 132±1 326) μmol/d,t=3.6,P＜0.05].Also,the mean of both Ccr and Cua were higher [(119±61) ml/min vs (75±39) ml/min,t=3.6,P＜0.05;(6.3±3.6) ml/min vs (3.2±2.0)ml/min,t=l.4,P＜0.05].Urinary pH was negatively correlated with uric acid stone in primary gouty patients (r=-0.212,P＜0.01);The total excretion of urinary uric acid was positively correlated with uric acid stones formation (r=0.633,P＜0.05).High urinary uric acid excretion and Ccr were independent risk factors for uric acid stone formation in primary gout patients.Conclusion Urine pH is negatively correlated with uric acid stone formation.Urinary analysis of 24-hour uric acid and Ccr are risk factors for pure uric acid urolithiasis in primary gout patients.