Gout Urate Cryst. Depos. Dis., Volume 1, Issue 2 (June 2023) – 4 articles

Together with the substantial role of genetic factors, serum urate levels and the occurrence of gout are also heavily driven by environmental and clinical factors, including adiposity, dietary patterns, alcohol, kidney function, and diuretic medication use. These are, in turn, greatly influenced by the social determinants of health, which encompass access to health care, availability of healthy foods, and opportunities for physical activity but also education, income, social norms, and racism, among other forces. Gout-related health disparities have been described for Māori and Pacific people in New Zealand, but racial disparities in gout prevalence and outcomes between Black and White Americans have been under-recognised, and particularly, sex-specific data are scarce. In this article we review evidence from prior cohort studies and contemporary national-level data which show the incidence and prevalence of gout and hyperuricemia in Black adults in the US have come to exceed that in White adults and are disproportionately greater in Black women. Importantly, this emerging disparity can be attributed entirely to social determinants of health, including higher levels of adiposity and poverty in Black women compared to White women and lower kidney function and poorer quality diet among Black men compared to White men. Furthermore, Black patients with gout have received poorer quality gout-related care and experienced higher levels of healthcare use, especially Black women. While identifying targets for culturally safe interventions for addressing risk factor disparities is essential, evidence gaps remain about potential disparities in longer-term outcomes of gout, including cardio-metabolic-kidney endpoints and premature mortality. Sociodemographically diverse, population-based longitudinal cohort studies, research on implementation strategies for improved gout care delivery models for underserved groups, and efforts to minimise structural racism and its effects are key to achieving health equity in gout. Full article

(1) The Multi-Ethnic Study of Atherosclerosis (MESA) is a multi-center longitudinal cohort study designed to investigate the risk factors associated with the incidence of CVD. The purpose of this study is to examine the impact of gout on incident CVD. (2) Participants reporting the use of gout-specific medications (urate lowering drugs or colchicine) were compared with non-users. Kaplan–Meier survival curves and multivariable models to control for known CV risk factors evaluated hazard ratios (HR) between participants taking gout medications versus those not taking gout medications. (3) For the 6734 participants, analyses were stratified by gender owing to a gout-gender interaction. For the 164 male and 59 female participants taking gout medications, Kaplan–Meier (unadjusted) survival curves demonstrate that participants taking gout medications have higher rates of CVD than participants not taking gout medications, particularly for women. After controlling for known CV risk factors, the adjusted HR for female participants taking gout medications was 1.79 (0.99, 3.23), p = 0.05; the adjusted HR for male participants on gout medications was 1.20 (0.81, 1.77), p = 0.36; (4) Participants treated for gout in this study have many comorbid conditions with known CVD risk factors, making it difficult to confirm the independent effect of gout on CVD. There are a paucity of data on women with gout. These findings suggest that there is a clinically meaningful and potentially greater risk of CVD among women with gout as compared to men. Full article

Aggregates are one of the elementary lesions seen on musculoskeletal ultrasound (US) in gout patients as defined by Outcome Measures in Rheumatology (OMERACT). The aim of this study was to evaluate the threshold of detection of aggregate findings on ultrasound and to analyze these findings with corresponding compensated light microscope (CPLM) images in vitro. Patient derived monosodium urate (MSU) crystals were obtained from two separate patients with gout during routine clinical care. In addition, fabricated in-house synthetic MSU crystals were used for comparison. Each sample was scanned using a GE Logic ultrasound machine and corresponding CPLM images obtained. As the aggregates became imperceptible by ultrasound, MSU clumping by CPLM examination was no longer detectable and crystal density per high power field fell markedly. Aggregates on US images are present only from patient-derived samples likely representing MSU crystal clustering or packing. Thus, when synovial aspiration is considered, a joint with aggregates on US would be a more suitable target with a higher likelihood of noting MSU crystals. Full article

The detection and differentiation of BCP and CPP crystals in calcified tissue is an important factor in the context of research and potential future treatment of osteoarthritis and chondrocalcinosis. Current standard methods originate from clinical practice and often lack precision in the correct identification of the calcium crystal type. In this work, a step-by-step guide for the use of the high-resolution imaging methods of tissue sections, Raman spectroscopy and scanning electron microscopy (SEM) in combination with energy-dispersive X-ray spectroscopy (EDS), for calcium crystal identification is presented. Sample preparation including Von Kossa staining, measurement and measurement parameters, data processing and data analysis methods are discussed and described. Furthermore, the different methods are compared to show advantages and disadvantages. Overall, Raman spectroscopy is a reasonable method from an economic point of view and regarding the time/effort required for acquiring highly reliable data in calcium crystal identification. Potentially, semi-quantitative results can be obtained with little effort and without the destruction of the respective test sample. The analysis/penetration depth during the Raman measurements, which is not precisely defined, poses a potential problem for accuracy. SEM can also be used for this task but requires more time, advanced technical knowledge and a pre-treatment of the samples using, e.g., gold sputtering, which may distort further analysis on the specific specimen. Therefore, this technique yields additional value compared to Raman spectroscopy only with additional research questions needed to be answered in the same sample, such as analysis of the sample topography or analysis of other unknown particles/deposits using EDS. The methods described in this manuscript are helpful for retrospective analyses in the context of research, but can also be used for potential future treatment strategies to discriminate between osteoarthritis and chondrocalcinosis patients. Full article