Positive direct antiglobulin test in COVID-19 patients: Decision-making process

Direct antiglobulin test type, red blood cell distribution width, and estimated glomerular filtration rate for early prediction of in-hospital mortality of patients with COVID-19

Objective

This study aimed to investigate the correlation between COVID-19 and the direct antiglobulin test (DAT) and establish an in-hospital mortality risk predictive model based on the DAT type, which can be used for the early prediction of inpatients with COVID-19.

Methods

In this study, 502 patients admitted to our hospital who underwent DAT testing from January 29 to February 8, 2023, were included (252 DAT-positive and 250 DAT-negative). Among them, 241 cases of COVID-19 were screened(171 DAT-positive and 70 DAT-negative), clinical and laboratory indicators were compared between DAT-positive and DAT-negative groups. Univariate and multivariate logistic regression analysis, the Kaplan-Meier survival curve and receiver operating curves were used to explore the relation between the DAT type and in-hospital mortality of patients with COVID-19.

Results

The proportion of confirmed COVID-19 cases was higher in the DAT-positive group than in the DAT-negative group (67.9 % vs. 28.0 %, P < 0.05). Patients with COVID-19 in the DAT-positive group had higher age-adjusted Charlson comorbidity index scores, red blood cell distribution width (RDW), lactate dehydrogenase, prothrombin time, D-dimer, creatinine, and high-sensitive cardiac troponin T levels than the negative group (P < 0.05), In contrast, hemoglobin and estimated glomerular filtration rate (eGFR) levels were lower in the DAT-positive group. The DAT-positive group also had a higher red blood cell usage volume and in-hospital mortality rate than the DAT-negative group. The mortality rate of patients with COVID-19 with both IgG and C3d positive was higher than that of the other groups. Multivariate logistic regression analysis showed that RDW and eGFR were associated with mortality in patients with COVID-19. The combined predictive model of DAT type, RDW, and eGFR showed an area under the curve of 0.782, sensitivity of 0.769, and specificity of 0.712 in predicting in-hospital mortality risk in patients with COVID-19.

Conclusion

The established predictive model for in-hospital mortality risk of patients with COVID-19 based on DAT type, RDW, and eGFR can provide a basis for timely intervention to reduce the mortality rates of patients with COVID-19. This model is accessible at https://jijijiduola.shinyapps.io/0531// for research purposes.

Clinical and laboratory profile of patients with positive direct antiglobulin test attended at a university hospital in Goias, Brazil

OBJECTIVE

To clinically and laboratory characterize patients with a positive direct antiglobulin test (DAT) treated at the Hospital das Clínicas of the Federal University of Goiás (HC-UFG).

METHODS

A retrospective, descriptive, cross-sectional study was carried out collecting data from medical records of patients with a positive DAT who were treated at HC-UFG between August 2021 and August 2022.

RESULTS

Eighty-four patients with positive polyspecific DAT results were screened in the clinical laboratory. Fifty-four patients had a laboratory profile compatible with autoimmune hemolytic anemia (AIHA), however, among these, 16 patients already had a diagnosis of AIHA in their medical records. The most common symptoms present among AIHA patients were pallor, asthenia, fatigue and dyspnea. For the remaining patients, the most common symptoms were severe thrombocytopenia, anemia, renal dysfunction, fever, myalgia, headache, thrombosis, asthenia, hematuria and joint pain. Only one patient had primary AIHA, that is, he had no evident underlying disease. The majority of AIHA patients (75 %) underwent corticosteroid therapy with 60 % having a positive response. For patients without AIHA, prednisone was the most frequently prescribed medication in 17 (25 %) patients, followed by hydroxychloroquine (14 patients - 20.1 %).

CONCLUSION

It is essential to evaluate patients with positive DAT in detail in order to understand the real clinical case. The DAT serological result alone does not arrive at a conclusive diagnosis of AIHA, and so it must be evaluated in conjunction with both clinical data and other laboratory tests, such as hemoglobin concentration and hemolysis tests (reticulocytes, lactate dehydrogenase and/or haptoglobin).