Procalcitonin levels in COVID-19 patients are strongly associated with mortality and ICU acceptance in an underserved, inner city population

Rationale: The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes COVID-19, has led to a global health crisis unlike any our contemporaries have witnessed before. SUNY Downstate Health Sciences University was designated as one of three COVID-19-only hospitals on March 28, 2020. This retrospective, single-center observational study grants a unique perspective surrounding the experience of the critical care service at a public institution serving a predominantly Afro-Caribbean, inner city population. Methods: Between March 11 and April 30, 2020, the critical care service was consulted for a total of 271 COVID-19 patients. We queried the electronic medical record for patient visits with critical care consult notes and collected data on demographics, comorbidities, ICU acceptance, treatment strategies, and clinical outcomes. Non-COVIDrelated consults were excluded. Chi-squared tests compared categorical variables, and independent samples ttest assessed differences in continuous variables based on mortality and ICU admission status. Logistic regression models determined if various factors independently predicted the odds of mortality. We conducted retrospective analyses to identify factors associated with survival and ICU acceptance. Results: Of the 271 patients with critical care consults, 33% (n=89) survived and 67% (n=182) expired. At the bivariate level, age, BUN, and neutrophil percentage were significantly associated with mortality, with age showing the strongest correlation (age: survivors, 61.62±1.50 vs. non-survivors, 68.98±0.85, p<0.001). There was a significant association between neutrophil percentage and mortality in the univariate logistic regression model (Q4 vs. Q1, OR 2.73, 95% CI (1.28-5.82), p trend = 0.044). In the multivariate analyses, procalcitonin exhibited a positive correlation with the odds of mortality, adjusting for age, sex, and race/ethnicity (procalcitonin: Q4 vs. Q1, OR 5.65, 95% CI (2.14-14.9), p trend <0.001). Adjusting for the same covariates, platelets exhibited a negative correlation with the odds of mortality (Q4 vs. Q1, OR 0.47, 95% CI (0.22-0.998), p trend = 0.010). Interestingly, of these factors, only elevated procalcitonin levels were associated with an increased likelihood of ICU acceptance. Conclusions: This retrospective, observational study during the first peak of the COVID-19 pandemic identified key factors linked to disease severity and outcomes. Of note, procalcitonin was the factor most strongly associated with both mortality and likelihood of ICU acceptance at the bivariate level. Respiratory failure is the primary cause of death in COVID-19, and our data suggests that procalcitonin is a useful marker that accurately reflects the severity of lung involvement during SARS-CoV-2 infection.

Complement c3 a-chain as an indicator of disease severity in COVID-19

INTRODUCTION: As we combat the novel coronavirus SARS-CoV-2, elucidating its immunological pathogenesis is vital for both understanding and treating the disease. A few case studies have suggested that the complement system may play an important role in the course of infection, but its specific role is unclear. Our group has shown that higher circulating levels of the complement C3, particularly C3 α-chain, can be a significant predictor of survival in septic shock patients. We therefore sought to investigate if a similar relationship could be seen in SARS-CoV-2. METHODS: Thirty-six COVID-19 patients were consented for this study. Serial blood samples were collected at different time points from 22 patients not in the ICU and 14 in the ICU at the time of collection. The plasma samples were analyzed using Western Blot for circulating C3 α-chain levels. Clinical data on hematologic, respiratory, renal and coagulation status were collected. The data were analyzed for differences in ICU and Non-ICU patients and for correlations of C3 α-chain levels and clinical parameters. RESULTS: In ICU patients, in mean levels of C3 α-chain had a statistically significant increase from Days 0-5 since admission to Days 16-20 (p = 0.042). C3 α-chain levels were positively correlated with time since admission (R = 0.5401, p = 0.0115). In ICU patients, C3 α-chain levels were negatively correlated with Creatinine levels (R = -0.4515, p<0.05), Neutrophil Percentage (R = -0.5525, p<0.001) and Absolute Count (R = -0.6297, p<0.001) and positively correlated with Lymphocyte Percentage (R= 0.6748, p<0.001). In Non-ICU patients, C3 α-chain levels were negatively correlated with Neutrophil Percentage (R = -0.4929, p<0.05), BUN levels (R = -0.5055, p<0.001), and positively correlated with Lymphocyte Percentage (R = 0.45, p<0.05) and Absolute Count (R = 0.6134, p<0.001) and platelet levels (R = 0.4636, p<0.05). CONCLUSIONS: In summary, levels of circulating C3 α- chain increased with time in ICU patients. C3 α-chain levels negatively correlated with renal injury markers and systemic neutrophil levels. Moreover, C3 α-chain levels positively correlated with circulating lymphocyte levels. These results indicate that native C3 is important in fighting against COVID-19 infection and may be a critical prognostic marker of disease progression.