Nickan Research Institute Immunopathologia Persa 2423-8015 11 2 2025 07 01 Low platelet counts and monocytosis were associated with reduced risk of severe COVID-19 manifestation: a single-center study from Indonesia e40595 e40595 10.34172/ipp.2025.40595 EN Mohammad Subkhan https://orcid.org/0000-0002-4491-9663 Thariq Malikul Mulki https://orcid.org/0009-0007-5553-1393 Nabil Salim Ambar https://orcid.org/0000-0002-9849-6336 Laily Irfana https://orcid.org/0000-0003-1063-5483 Sri Widyaningsih https://orcid.org/0000-0003-1475-0411 Putu Bagus Dharma Permana https://orcid.org/0000-0001-6458-0866 Agung Dwi Wahyu Widodo https://orcid.org/0000-0003-1880-8799 Aprilia Paramitasari https://orcid.org/0000-0001-7499-4712 Journal Article 10.34172/ipp.2025.40595 2023 09 29 2024 11 15 Introduction: Severe morbidity and mortality in COVID-19 are linked to an inflammatory ‘cytokine storm’ driven by hyperactive macrophages and altered monocyte function. Identifying early immune predictors of severe COVID-19 outcomes is critical for optimizing patient care and resource allocation, especially under a resource-limited setting. Objectives: This study aimed to investigate the relationship between monocyte and platelet levels and COVID-19 severity at a secondary hospital in East Java, Indonesia. Patients and Methods: A single-center, cross-sectional study was conducted by utilizing electronic medical health records from 100 patients admitted to the Siti Khodijah Muhaammadiyah Sepanjang hospital May to September 2021. Initial complete blood counts were retrieved from adult patients who tested positive for COVID-19 by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR ). A backward-stepwise multivariate regression model was incorporated to evaluate the association between platelet and monocyte levels with COVID-19 severity. Results: Despite the non-association in the bivariate analysis, thrombocytopenia significantly reduced the risk of severe COVID-19 manifestation in the multivariate model (aPR 0.184; 95% CI: 0.047-0.722). Interestingly, patients with monocytosis had a lower risk of the severe disease compared to those with normal monocytes both in the bivariate and multivariate analyses (PR 0.364; 95% CI [0.157-0.841] and aPR 0.334; 95% CI [0.126-0.882], respectively). However, there was no significant increase in severity among those presenting with low monocyte or high platelet counts. Conclusion: There is a unidirectional association between low platelets and high monocyte levels with severe manifestations of COVID-19 disease. Further research is warranted to validate these findings and explore their utility in risk stratification and clinical management of COVID-19 patients.