Analysis of risk factors influencing the detection rate of urate crystal by dual energy computed tomography / 北京大学学报(医学版)

OBJECTIVE@#To explore the risk factors of detection of uric acid crystals by dual energy CT (DECT) in patients with gout diagnosed by gold standard.@*METHODS@#From June 2011 to December 2018, clinical data of 29 patients were collected who were diagnosed with acute or chronic gout by positive polarized light analysis of joint synovial fluid in First Hospital of Peking University. Chi-square test, Logistic regression and t-test were used. The relationship between DECT and the clinical data, laboratory examination and drug treatment were analyzed.@*RESULTS@#In this study, 29 patients were included, of whom, 22 patients were detected with uric acid crystals by DECT, and 7 patients were not. According to whether the uric acid crystals were detected or not by DECT, the patients were divided into two groups. Compared with the negative group, the patients were older in positive group [(47±12) vs. (39±11) years, P=0.15], had higher body bass index (BMI) [(27.9±3.7) vs. (22.8±2.1) kg/m2, P=0.002], longer gout disease duration [(135±102) vs.(45±53) months, P=0.035], higher in the highest serum uric acid in history [(643±121) vs. (543±103) μmol/L, P=0.043]. Although uric acid near DECT in positive group was higher than in negative group, there was no statistical difference [(558±150) vs. (513±89) μmol/L, P=0.497]. Comparing positive group with negative group, the percentage of the patients in acute phase was higher than in chronic phase [18(81.8%) vs. 4(57%), P=0.311];the percentage of the patients taking uric-acid-lowering drugs was higher than the other group [22(100%) vs. 5 (71%), P=0.052];the percentage of the patients with recurrent typical attacks was higher than that of those without typical attacks [22 (100%) vs.6 (85%), P=0.241]. The consistency of symptoms and the finding of uric acid crystals by DECT had been compared between the joints. The right knee joint had the highest consistency (Kappa=0.627), followed by the left MTP1 (Kappa=0.58), the right metatarsophalangeal 1(MTP1, Kappa=0.551) and the left knee (Kappa=0.494), all of which had statistical significance. The consistency of the ankle joint was lower (the right ankle joint: Kappa=0.19, the left ankle joint: Kappa=0.256), showing no statistical significance. BMI (kg/m2) [2.307 (1.139-4.670), P=0.02], gout duration (years) [0.306 (0.906-4.881), P=0.186], and the highest uric acid level in history (mg/dL) [0.023 (0.981-2.764), P=0.137] had relationship to the positive result of urate crystals in DECT.@*CONCLUSION@#Gout patients with larger BMI, higher previous highest uric acid value and longer gout duration had higher sensitivity of the positive result in DECT.

Risk factors and diagnostic value for ultrasound-detected tendon monosodium urate crystal deposition in patients with gout / 北京大学学报(医学版)

OBJECTIVE@#To evaluate frequency and patterns, risk factors of MSU (monosodium urate) crystal deposition at lower extremity tendon by ultrasonography in gout patients, and to explore diagnostic value by ultrasonography.@*METHODS@#Patients diagnosed with gout and age matched healthy controls had ultrasound scanning of both feet and knees including joints and tendons (achilles, quadriceps, and patellar tendon). Readers who scored the ultrasound scans for MSU crystal deposition were blinded to the patients' clinical diagnoses. Clinical characteristics were compared between positive and negative crystal deposition groups by US, and risk factors of MSU deposition in tendons were analyzed. Diagnostic values of MSU deposition were evaluated by ultrasonography according with positive MSU crystal in synovial fluid or tophi by polarized microscopy.@*RESULTS@#Eighty patients and eighty healthy controls were included. Thity-three patients (47.5%) had tophi by physical examination. The achilles tendon was the most commonly involved tendon site 41(51.2%), followed by the quadriceps tendons 22(27.5%), and patella tendon 10(12.5%). There were no MSU deposition in healthy control group at tendon by ultrasonography. Compared with negative MSU deposition at tendon site by ultrasonography, tendon MSU positive patients had longer mean gout duration [(87.3±40.9) months vs. (7.7±2.6) months, P=0.001];higher frequency of gout flare [2(1, 2) /year vs. 1(1, 1) /year, P=0.001]; higher BMI [(26.3±2.5) kg/m2vs. (23.3±2.1) kg/m2, P=0.05]. Also, the mean serum uric acid and creatinine levels were higher in tendon MSU positive group [(584.6±87.6) μmol/L vs. (460.4±96.7) μmol/L, P=0.001] and [(90.9±33.3) μmol/L vs. (70.6±40.2) μmol/L, P=0.02] separately. Logistic regression analysis showed gout duration and flare frequency were independent risk factors for MSU deposition at tendon by ultrasonography (P < 0.01). Joint or tophi aspirations were performed in all the eighty gout patients, and positive MSU crystals in synovial fluid analysis by polarized microscopy were defined as the golden standard of gout diagnosis. When compared with the golden standard, the sensitivity and specificity were 94.0% and 78.0% separately for MSU deposition at tendon by ultrasonography.@*CONCLUSION@#Tendon involvement at the lower extremity tendons in gout is very common. Long gout disease duration and high frequency of gout flare are both independent risk factors of tendon MSU deposition by ultrasonography. Ultrasonography had good sensitivity and specificity for detecting tendinous tophi and aggregates.

A case of gout secondary to primary myelofibrosis / 北京大学学报(医学版)

A 52-year-old man was referred to our department with a 2-year history of polyarthritis. He was diagnosed as gout due to acute arthritis of bilateral feet dorsum 2 years ago,but he didn't receive any standard treatment. 1 year ago,there were more and more joints evolved during the gout attack, and many subcutaneous nodules occurred. When he presented to our clinic 1 month ago,the urate acid level was as high as 715 μmol/L. Moreover, we could find bone erosion in the X rays of his hand and foot,as well as synovitis,double contour sign and tophus on the ultrasound examination. The diagnosis of gout was clearly and definitely. However, he had leukocytosis and thrombocytosis for 4 years in the past history, and the urate acid level was only 400 μmol/L at that time. He also had well-controlled hypertension. The family history was unremarkable. Furthermore, we found megalosplenia on his physical examination. The bone marrow examination showed myelofibrosis and JAK2 V617F gene was positive. He was diagnosed as primary myelofibrosis and treated with interferon-α, together with urate acid-lowing therapy (febuxostat 60 mg once daily). Following-up for 1 year,the dosage of febuxostat decreased to 40 mg once daily, and the patient didn't have gout attack again, some of the tophus diminished, and the urate acid level ranged from 400 to 500 μmol/L. Gout is a common disease in clinical practice,usually combined with metabolic syndrome,chronic renal failure and specific drugs using (diuretic and calcineurin inhibitors). However,it is relatively rare to see gout associated with myeloproliferative diseases, including polycythemia vera, primary thrombocythemia, primary myelofibrosis and chronic myelocytic leukemia. In these diseases, the turnover of nucleic acids is greatly augmented, and an excess of purine metabolites, including uric acid, is released. In the natural course of gout, the appearance of tophus from the first onset of arthritis usually takes several years. This patient only had one traditional risk factor, but his urate acid level was remarkably high and he developed tophus in a short term. After treatment of primary myelofibrosis, the symptom of gout partially alleviated. Careful physical examination and medical history taking lead to the diagnosis of secondary gout, which should be reminded in the daily practice.

Correlation between nailfold capillaroscopic findings and presence of interstitial lung disease in systemic sclerosis patients / 北京大学学报(医学版)

OBJECTIVE@#To evaluate the correlation between nailfold capillaroscopic (NC) findings and the presence of interstitial lung disease (ILD) in systemic sclerosis (SSc) patients.@*METHODS@#We retrospectively involved 71 SSc patients, 45 patients with ILD. NC was performed in all the patients according to the standard method. The NC findings were semi-quantitatively scored, including enlarged and giant capillaries, hemorrhages, loss of capillaries, avascular areas, ramified/bushy capillaries and disorganization of the vascular array. The demographic and clinical data collected were gender, age, presence/absence of Raynaud phenomenon (RP), duration of RP, serological acute phase reactants and antibodies, presence of ILD (also evaluated the CT score for ILD) and pulmonary function parameters.@*RESULTS@#Among the 71 patients, the frequency of the women was 91.5%, the mean age was (52.59±12.77) years, and disease duration was (3.00±6.00) years. NC changes of the scleroderma pattern were observed in 90.1% patients. There were 45 patients with ILD and 26 patients without ILD. The patients with ILD had significantly higher loss of capillaries score [0.50 (1.03) vs. 0.00 (0.43), P=0.003], avascular area score [0.75 (1.24) vs. 0.25 (0.83), P=0.006] and ramified/bushy capillaries score [0.33 (0.88) vs. 0.13 (0.25), P=0.006] compared with those without ILD. Moreover, ramified/bushy capillaries score together with diffused SSc were independent risk factors for the presence of ILD. And the score of giant capillaries were significantly lower in the patients with more severe ILD group [0.25 (0.94) vs. 0.00 (0.28), for the mild and severe ILD groups respectively, P=0.019]. There was no statistically significant difference between the two groups with respect to the scores of enlarged capillaries, hemorrhages, or disorganization of the vascular array.@*CONCLUSION@#Capillary deletion and severe deformity in NC were associated with the presence of ILD in SSc patients. And patients with less giant capillaries had more severe ILD involvement. These indicated that NC maybe a useful tool to evaluate ILD in SSc.