Effectiveness of mid-regional pro-adrenomedullin, compared to other biomarkers (including lymphocyte subpopulations and immunoglobulins), as a prognostic biomarker in COVID-19 critically ill patients: New evidence from a 15-month observational prospective study

Background

Mid-regional pro-adrenomedullin (MR-proADM), an endothelium-related peptide, is a predictor of death and multi-organ failure in respiratory infections and sepsis and seems to be effective in identifying COVID-19 severe forms. The study aims to evaluate the effectiveness of MR-proADM in comparison to routine inflammatory biomarkers, lymphocyte subpopulations, and immunoglobulin (Ig) at an intensive care unit (ICU) admission and over time in predicting mortality in patients with severe COVID-19.

Methods

All adult patients with COVID-19 pneumonia admitted between March 2020 and June 2021 in the ICUs of a university hospital in Italy were enrolled. MR-proADM, lymphocyte subpopulations, Ig, and routine laboratory tests were measured within 48 h and on days 3 and 7. The log-rank test was used to compare survival curves with MR-proADM cutoff value of >1.5 nmol/L. Predictive ability was compared using the area under the curve (AUC) and 95% confidence interval (CI) of different receiver-operating characteristic curves.

Results

A total of 209 patients, with high clinical severity [SOFA 7, IQR 4-9; SAPS II 52, IQR 41-59; median viral pneumonia mortality score (MuLBSTA)-11, IQR 9-13] were enrolled. ICU and overall mortality were 55.5 and 60.8%, respectively. Procalcitonin, lactate dehydrogenase, D-dimer, the N-terminal prohormone of brain natriuretic peptide, myoglobin, troponin, neutrophil count, lymphocyte count, and natural killer lymphocyte count were significantly different between survivors and non-survivors, while lymphocyte subpopulations and Ig were not different in the two groups. MR-proADM was significantly higher in non-survivors (1.17 ± 0.73 vs. 2.31 ± 2.63, p < 0.0001). A value of >1.5 nmol/L was an independent risk factor for mortality at day 28 [odds ratio of 1.9 (95% CI: 1.220-3.060)] after adjusting for age, lactate at admission, SOFA, MuLBSTA, superinfections, cardiovascular disease, and respiratory disease. On days 3 and 7 of the ICU stay, the MR-proADM trend evaluated within 48 h of admission maintained a correlation with mortality (p < 0.0001). Compared to all other biomarkers considered, the MR-proADM value within 48 h had the best accuracy in predicting mortality at day 28 [AUC = 0.695 (95% CI: 0.624-0.759)].

Conclusion

MR-proADM seems to be the best biomarker for the stratification of mortality risk in critically ill patients with COVID-19. The Ig levels and lymphocyte subpopulations (except for natural killers) seem not to be correlated with mortality. Larger, multicentric studies are needed to confirm these findings.

Proadrenomedullin in the Management of COVID-19 Critically Ill Patients in Intensive Care Unit: A Systematic Review and Meta-Analysis of Evidence and Uncertainties in Existing Literature

Mid-regional proadrenomedullin (MR-proADM) is a new biomarker of endothelial damage and its clinical use is increasing in sepsis and respiratory infections and recently in SARS-CoV-2 infection. We conducted a systematic review and meta-analysis to clarify the use of MR-proADM in severe COVID-19 disease. After Pubmed, Embase, and Scopus search, registries, and gray literature, deduplication, and selection of full-texts, we found 21 studies addressing the use of proadrenomedullin in COVID-19. All the studies were published between 2020 and 2022 from European countries. A total of 9 studies enrolled Intensive Care Unit (ICU) patients, 4 were conducted in the Emergency Department, and 8 had mixed populations. Regarding the ICU critically ill patients, 4 studies evaluating survival as primary outcome were available, of which 3 reported completed data. Combining the selected studies in a meta-analysis, a total of 252 patients were enrolled; of these, 182 were survivors and 70 were non-survivors. At the admission to the ICU, the average MR-proADM level in survivor patients was 1.01 versus 1.64 in non-survivor patients. The mean differences of MR-proADM values in survivors vs. non-survivors was −0.96 (95% CI from −1.26, to −0.65). Test for overall effect: Z = 6.19 (p < 0.00001) and heterogeneity was I2 = 0%. MR-proADM ICU admission levels seem to predict mortality among the critical COVID-19 population. Further, prospective studies, focused on critically ill patients and investigating a reliable MR-proADM cut-off, are needed to provide adequate guidance to its use in severe COVID-19.

Reduced immunoglobulin kappa/lambda light chain ratio in perinatally HIV-1-infected children

In 27 perinatally human immunodeficiency virus type 1 (HIV-1)-infected children, we measured, by immunonephelometry, the kappa/lambda light chain ratio (KLR) of serum immunoglobulins. The latter is a recently available laboratory index reflecting the balance between the synthesis of K isotypes and L isotypes. KLR was consistent over time in each subject, and was significantly lower than that of an age-matched normal population, independently of disease status and therapy. These data indicate a bias, in these subjects, to produce preferentially lambda rather than kappa light chains, contributing to the multiple B-cell abnormalities in HIV-1-infected children.

[Caloric intake and bone mineral content in obese and normal weight subjects]

Bearing in mind the reports which clearly document the constant dissociation between daily calorie intake from diet, obesity and the positive effects of the mechanical load on bone trophism, the possible correlation between total daily calorie intake of some nutrients (Ca, P and vitamin D) on the one hand, and bone mineral density (BMD) on the other was evaluated in 61 obese women. The results appear to indicate that the higher BMD in obese compared to normal weight subjects may largely depend on the presence of notoriously high estrogen levels which allow a better efficacy and use of dietary calcium.

[Description of an acquisition, management and archiving system for digital images]

The authors present a digitalizing and archiving system, for radiologic pictures. This system is composed by a camera, a microcomputer (MacIntosh II) with a digitalizing card and a great capacity optical disk (WORM) for storage. Acquiring and archiving are automatically driven by a special soft. The principal qualities of this system are simplicity for the user, speed and low cost.