Identifying The Association Between Inflammatory Markers And Cycle Threshold Of RT-PCR In Paediatric COVID-19 Infection

Abstract

Background: Pneumonia caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) poses a significant threat to
healthcare and is classified as a global pandemic. This study aims to find the association between the inflammatory marker CRP, LDH,
Ferritin, D-dimer, and the cycle threshold of SARS CoV2 in the pediatric population
Methods: Patients admitted with COVID-19 infection (SARS CoV2 Real-Time PCR positive) from November 2020 to October 2021,
were included in this study. The cycle threshold (Ct) of SARS CoV2 Real time-PCR test, serum lactate dehydrogenase (LDH), C
reactive protein (CRP), serum Ferritin, D-dimer, white cell counts including absolute neutrophil and absolute lymphocyte count were
analysed in these patients. Patients were divided into two groups based on the Ct (cycle threshold) value of SARS CoV2 RT-PCR for
statistical analysis (Ct<=26 and Ct>26). Statistical analysis using the area under the curve with a Z score (95% confidence interval)
was used to detect the significance between the serum parameters and the cycle threshold of RT-PCR in COVID-19 infection. Patients
were grouped into asymptomatic, mild, moderate, and severe COVID-19 based on their clinical presentation. Unpaired t-test was used
to identify a statistically significant correlation between clinical presentation and the serological parameters
Results: Out of 1125 suspected COVID-19 patients, 47 patients (4% positivity) were identified as COVID-19 positive using RT-PCR.
The mean age group of males was 8.74±5.11 years and females was 9.45±5.87 years. 2% of patients had severe and 13% of patients
had moderate COVID-19 clinical presentation. The area under the curve analysis using a Z score with 95% CI identified a statistically
significant correlation between the cycle threshold of SARS CoV2 RT -PCR and absolute lymphocyte count (p-value 0.04). No
statistically significant correlation was identified between D-dimer, serum LDH, serum ferritin, total white cell count, and the cycle
threshold of SARS CoV2 RT-PCR. Unpaired t-test showed a statistically significant correlation between clinical presentation and LDH,
CRP, and D-dimer.
Conclusion: The cycle threshold of RT-PCR does not show an association with serological parameters such as CRP, LDH, D-dimer,
and serum ferritin. Absolute lymphocyte count can be used as an indicator to identify patients with low Ct values in SARS CoV2 RTPCR.