The Lines That Held Us: Assessing Racial and Socioeconomic Disparities in SARS-CoV-2 Testing

BACKGROUND

Racial disparities in SARS-CoV-2 prevalence are apparent. Race is a sociocultural construct, necessitating investigation into how sociocultural factors contribute.

METHODS

This cross-sectional study linked laboratory data of adult patients between February 29 and May 15, 2020 with socio-demographics variables from the 2018 American Community Survey (ACS). Medical sites included healthcare organizations in Michigan, New York, North Carolina, California, Florida, Pennsylvania, and Washington. Race was treated as a proxy for racism and not biological essentialism. Laboratory data included patient age, sex, race, ethnicity, test result, test location, and residential ZIP code. ACS data included economic and educational variables contributing to an SES Index, population density, proportion Medicaid, and racial composition for corresponding ZIP code. Associations between race/socioeconomic variables and test results were examined using odds ratios (OR).

RESULTS

Of 126 452 patients [mean (SD) age 51.9 (18.4) years; 52 747 (41.7%) men; 68 856 (54.5%) White and 27 805 (22.0%) Black], 18 905 (15.0%) tested positive. Of positive tests, 5238 (SD 27.7%) were White and 7223 (SD 38.2%) were Black. Black race increased the odds of a positive test; this finding was consistent across sites [OR 2.11 (95% CI 1.95-2.29)]. When subset by race, higher SES increased the odds of a positive test for White patients [OR 1.10 (95% CI 1.05-1.16)] but decreased the odds for Black patients [OR 0.92 (95% CI 0.86-0.99)]. Black patients, but not White patients, who tested positive overwhelmingly resided in more densely populated areas.

CONCLUSIONS

Black race was associated with SARS-CoV-2 positivity and the relationship between SES and test positivity differed by race, suggesting the impact of socioeconomic status on test positivity is race-specific.

Using a combination of gangliosides and cell surface vimentin as surface biomarkers for isolating osteosarcoma cells in microfluidic devices

Background

Osteosarcoma (OS) is the most common primary bone tumor and the third leading cause of pediatric cancer deaths. Liquid biopsies are an alternative to current diagnostic imaging modalities that can be used to monitor treatment efficacy and the development of metastases. This study addresses the use of novel biomarkers to detect circulating osteosarcoma cells.

Procedures

Flow cytometry was used to evaluate the relative expression of epithelial cell adhesion molecule (EpCAM), ganglioside 2 and 3 (GD2/3), and cell surface vimentin (CSV) on a panel of OS cell lines. A microfluidic device was used to affirm the efficacy of GD2/3 and CSV to capture CTCs. Once captured, CTCs on the device are enumerated and the capture efficiency for each marker is measured. Patient samples were captured using the LFAM chip.

Results

We report the evaluation of GD2, GD3, and CSV as markers for OS cell capture in cell lines and in patient samples. The results of our capture studies correlate with our flow cytometry data and have shown a low capture efficiency of OS cells using EpCAM antibodies, while showing a moderate capture efficiency of OS cells using the GD2, GD3, and CSV antibodies independently. The combination of biomarkers demonstrate a high capture efficiency of approximately 80%. This is further supported by the detection of 1-1.5 CTCs per mL of blood using GD2 + CSV in OS patient samples.

Conclusions

The combination of GD2 + CSV significantly increased the capture efficacy of OS cells. The detection of CTCs through routine blood sampling may be used clinically for earlier detection of metastases and monitoring the therapeutic effect of treatments in metastatic osteosarcomas.

A Critical Review on the Use of Race in Understanding Racial Disparities in Preeclampsia

BACKGROUND

Preeclampsia is a significant cause of maternal morbidity and mortality, affecting up to 8% of pregnancies globally. Although the precise etiology is still under study, the literature suggests that vascular changes reduce placental perfusion and affect the remodeling of spiral arteries to create the hallmark feature of preeclampsia: elevated blood pressure. Screening for preeclampsia is currently recommended for all pregnant women, particularly if risk factors exist. A noted risk factor codified in guidelines is "African-American race."

CONTENT

We summarize the racial disparities in preeclampsia incidence, morbidity, and mortality. We consider the limitations of using race to understand disparities by also examining multiethnic, immigration, and international studies. We then critically evaluate laboratory analytes associated with racial disparities of preeclampsia and explore other mechanisms of action, such as socioeconomic status, stress, and access to care.

SUMMARY

Black and African-American women are consistently at higher risk of preeclampsia incidence, morbidity, and mortality than their white counterparts. Asian women are consistently at lower risk of preeclampsia, whereas the association for Hispanic women remains unclear. When these broad racial categories are subdivided by geographic or cultural origin, preeclampsia disparities within racial groups are identified. The limited literature suggests that sub-Saharan African immigrants tend to have a higher risk of preeclampsia than US-born white populations but a lower risk than US-born Black women. Existing studies seeking to identify racial differences in analytes have limited research designs and tend to operationalize race as a proxy for biologically inherent (i.e., genetic) differences between races despite a plethora of other possible explanatory mechanisms.