‘Immune-inflammatory markers & clinical characteristics for outcomes in hospitalized SARS-CoV-2 infected patients of Pakistan: a retrospective analysis’

ABSTRACT

Objective

Accumulating evidence suggests the role of immune-inflammatory markers in early risk stratification and prognostication of COVID-19 patients. We aimed to evaluate their association with severity and the development of diagnostic scores with optimal thresholds in critical patients.

Setting and participants

This retrospective case study includes hospitalized COVID-19 patients from March 2019 to March, 2022, in the developing area teaching hospital in Pakistan. Polymerase chain reaction (PCR) positive patients, n = 467 were investigated for clinical outcomes, comorbidities and disease prognosis. The plasma levels of Interleukin-6 (IL-6), Lactate dehydrogenase (LDH), C-reactive protein (CRP), Procalcitonin (PCT), ferritin and Complete blood count markers were measured.

Results

Majority were males (58.8%) and patients with comorbidities had more severe disease. Hypertension and diabetes mellitus were the commonest comorbidities. Shortness of breath, myalgia and cough were the main symptoms. The hematological markers NLR, as well as the plasma levels of immune-inflammatory variables, IL-6, LDH, Procalcitonin, Erythrocyte sedimentation rate, Ferritin were markedly raised in severe and critical patients (p < 0.0001 for these markers). ROC analysis supports IL-6 as the most accurate marker with high prognostic relevance with proposed cut-off threshold (43 pg/ml), determining >90% of patients in terms of COVID-19 severity (AUC = 0.93, 91.7%, se; 90.3%sp). Furthermore, positive correlation with all other markers including NLR with cut-off = 2.99 (AUC = 0.87, se = 89.8%, sp = 88.4%), CRP with cut-offs at 42.9 mg/l, (AUC = 0.883, se = 89.3% and sp = 78.6%), LDH cut-off at 267μg/L, evidenced in >80% patients (AUC = 0.834 se = 84% and sp = 80%). Additionally, ESR and ferritin have the corresponding AUC 0.81 and 0.813 with cut-off at 55 mm/hr and 370, respectively.

Conclusion

Investigating the immune-inflammatory markers can assist physicians in providing prompt treatment and ICU admission in terms of COVID-19 severity. As a result, which may reduce the overall mortality of COVID-19 patients.

KEYWORDS:

• COVID-19
• SARS-CoV-2
• immune-inflammatory markers
• disease severity
• diagnostic criteria

Acknowledgements

We are indebted to all the healthcare professionals and patients who by giving consent to use their data, paved the way towards it.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contributions

AK was involved in conception, design, analysis and final review. JA did the drafting and revising the paper. MS prepared the final draft. AN and MR collected data and revised the final draft for intellectual review.

Consent for publication

Informed consent was granted from all the study participants and sources whose data and figures were used.

Data availability

The datasets used and analyzed during the current study are available from the corresponding author on reasonable request.

Ethical approval

This study was approved by the Sahiwal medical college ethical committee (vide letter SLMC/DME/345) and Government of Pakistan. This study is in accordance to the principles of the ‘World Medical Association Helsinki Declaration’.