BIOMEDIKA
ISSN: 2085-8345.
E-ISSN: 2541-2582
Vol 18.
No.
1 Februari 2026 doi: 10.
23917/biomedika.
Diagnostic Test of Neutrophil Lymphocyte Ratio in Confirmed Covid-19 Positive Patient at RSUD Wonosari Muhammad Ariq Naufal Arofiq1.
Linda Rosita2.
Utami Mulyaningrum3
AFFILIATIONS
Medical Student.
Faculty of Medicine.
Universitas Islam Indonesia.
Central Java.
Indonesia Departement of Clinical Pathology.
Faculty of Medicine.
Universitas Islam Indonesia.
Central Java.
Indonesia Departement of Clinical Pathology.
Faculty of Medicine.
Universitas Islam Indonesia.
Central Java.
Indonesia
ABSTRACT
Coronavirus Disease 2019 (Covid-.
is an outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-.
The neutrophil lymphocyte ratio (NLR) biomarker is used as a parameter of inflammatory reactions which is also frequently evaluated in Covid-19.
In Covid-19 patients, there is often an increase in NLR through the mechanism of lymphocyte exhaustion.
This research to identify the performance of NLR in a diagnostic test for confirmed Covid-19 patients at RSUD Wonosari.
This study is analytical observational through a cross-sectional approach.
Sampling used a consecutive sampling technique.
The target population was suspected Covid-19 Data were analyzed by univariate.
ROC curve, and diagnostic tests.
A total of 75 suspected Covid-19 patients were found 33 male patients .
%), 42 female patients .
%), and the most aged> 55 years were 52 patients .
3%).
RT-PCR results found 57 patients were positive for Covid-19 .
%) and 18 patients were negative for Covid19 .
%).
ROC curve obtained AUC value 0.
<0.
95% CI 0.
with cut-off point NLROu 2.
33, sensitivity 91.
2%, specificity 50%.
NPV 64.
PPV 85.
LR 1.
81, and LR- 0.
NLR can be an initial diagnostic tool for Covid-19.
KEYWORDS:
Covid-19.
Diagnostic test.
NLR.
RT-PCR This work is licensed under a Creative Commons AttributionNonCommercial 4.
International License.
CORRESPONDING AUTHOR:
Linda Rosita E-mail: linda.
rosita@uii.
confirmed case confirmed 6.
182 cases positive INTRODUCTION Pandemic Coronavirus Disease 2019 (Covid-.
is an outbreak of disease caused by the Coronavirus for Covid-19 and figures death as many as 6.
or severe acute respiratory syndrome coronavirus 2 The diagnostic method recommended by WHO (SARS-CoV-.
Suspected viruses originate from to diagnose Covid-19 is the molecular detection traditional markets in the Chinese city of Wuhan and method/NAAT (Nucleic Acid Amplification Tes.
such spread with fast Because can be transmitted as RT-PCR examination.
RT-PCR examination has between humans .
uman-to-human transmissio.
the advantage of having high sensitivity and As this February, 2026, already reach figure of specificity and being able to detect antigens at low
779,073,803 cases confirmed Covid-19 positives However, this examination takes a worldwide by WHO and figures death as many as long time, is quite expensive, must have a special
7,109,103
applicator, and variations in samples can change the Indonesia Already Avalaible online at https://journals2.
id/index.
php/biomedika Diagnostic Test of Neutrophil Lymphocyte Ratio A (Muhammad Ariq Naufal Arofi.
results of the examination.
In this case, it is alternative for early COVID-19 diagnostic tools in necessary to consider other examinations such as secondary healthcare facilities, such as RSUD thoracic tomography or calculation of the profile of Wonosari, by comparing its performance directly the neutrophil lymphocyte ratio (NLR).
against the gold standard RT-PCR results.
Checking the NLR value has the advantage that METHODS it is easy to obtain by inspection alone Complete Study Design Blood Count (CBC), is affordable, simple, more This However, drawbacks where NLR values can also increase in other circumstances such as sepsis, long-term use of sectional design.
Setting and Respondents Retrieval process sample use technique of consecutive sampling conducted from September emotional stress, and pregnancy.
2 In research on 2021 to October year 2022.
The accumulated results 2021 with performance NLR cut-off point > 2.
sample will be tested using analysis univariate and have a marked sensitivity 75%, specificity 60%, and diagnostic tests with source sample form of AUC within level moderate accuracy 0.
723 in secondary data from record status medical patients diagnosing Covid-19.
3 The study evaluated the confirmed Covid-19 being treated at Wonosari effectiveness of the Neutrophil-to-Lymphocyte Ratio Hospital.
Population is patient suspected of Covid-19 (NLR) and Lymphocyte-to-Monocyte Ratio (LMR) as at the Wonosari Hospital.
The inclusion criteria in diagnostic parameters for COVID-19 diagnosis.
The this study are patient suspected of Covid-19 aged analysis revealed an optimal NLR cut-off value of over 18 years, have results of RT-PCR Covid-19 O2.
49, yielding a specificity of 80%, sensitivity of examination, and have results of complete blood 6%, positive predictive value (PPV) of 69%, and count (CBC) that includes mark neutrophils and negative predictive value (NPV) of 62.
1%, with an Under Area Curve (AUC) Research Furthermore, this study aims to fill the existing While various clinical conditions research gap regarding the diagnostic accuracy of can influence the Neutrophil-to-Lymphocyte Ratio NLR in the Indonesian clinical setting, specifically (NLR), this study specifically prioritized pregnancy within the Yogyakarta region, where localized data and immunodeficiency as primary exclusion criteria remains limited.
The primary objective is to validate due to their profound and consistent impact on whether NLR can serve as a reliable and accessible BIOMEDIKA.
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significantly skew the baseline data.
The sample size Data Analysis in the study was 77 people with 2 samples excluded The diagnostic test was analyzed using a Because pregnant so the total sample used as many Receiver Operating Characteristic (ROC) curve which as 75 people.
The predictor variables in this study is a yield curve between sensitivity and specificity at were the cut-off point NLR Ou 2.
33 referring to the various cut points.
From this analysis the researcher research by ynzsari S, sensitivity, and specificity of will get the value of the cut-off point which is the the NLR of Covid-19 patients, while the outcome normal, abnormal, or cut-off point for positive or variable was the RT-PCR status of Covid-19 patients.
negative test results for a disease with the optimal Data was analyzed in a manner univariate.
ROC cut-off point.
This analysis is used to assess the curve, and diagnostic tests with the application IBM ability of a diagnostic test whose measurement Statistical Package for the Social Sciences (SPSS) results are continuous scale to detect the presence Statistics 25.
This research has received ethical of a disease.
approval from the Research Ethics Committee of In addition, the value of Area Under the Curve RSUD Wonosari.
(AUC) can be obtained where AUC is the entire area The Variables.
Instruments, and Measurement under the curve formed from all sensitivity and 1specificity coordinates.
The application of the The instrument used in this study is a structured diagnostic test starts from inputting the NLR value form containing age, gender, symptom clinical, of suspected Covid-19 patients and RT-PCR status comorbid, outcome CBC examination.
RT-PCR Covidwhich then determines the optimal cut-off value by 19 status along with date inspection.
Complete Blood looking at the correct value classified is the highest.
Count (CBC) was performed using an automated After obtaining the optimal cut-off value, sensitivity, specificity.
LR , and LR-.
Then proceed with an neutrophil, and lymphocyte levels.
The molecular analysis using a 2x2 table to calculate the diagnosis was confirmed via RT-PCR.
Viral RNA was extracted from nasopharyngeal and oropharyngeal RESULT AND DISCUSSION swabs, with the presence of SARS-CoV-2 determined Of the 223 patient medical records taken at by the amplification of specific target genes .
Wonosari Hospital, a total of 75 research subjects ORF1ab.
N, and E gene.
according to the met the inclusion and exclusion criteria.
The detailed manufacturer's protocol.
The sample is secondary sample profile is described in Table 1.
data on patient medical records at Wonosari Hospital.
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probability that the NLR test will correctly distinguish Table 1.
Characteristics of Respondent Characteristic Result
between a randomly selected positive patient and a Age, years >55 Gender
Male
Woman
Comorbid
Hypertension Cardiovascular-Hypertension Cardiovascular-Hypertension-Dyslipidemia
Cardiovascular-Hypertension-COPD
Cardiovascular-Hypertension-CKD
Cardiovascular-Hypertension-DM
Dyslipidemia
Dyslipidemia-Hypertension Pneumonia
CKD
CKD-Hypertension DM-Hypertension DM-Hypertension-CKD
Without Comorbidities Symptom
Acute Respiratory Infections Non-Acute Respiratory Infections Mix
No Symptom
RT-PCR
Positive Negative 10 .
4 %)
As shown in Table 2, the normality test using the Kolmogorov-Smirnov method indicated that the data Consequently, the leukocyte, the absolute number of neutrophils, lymphocyte neutrophil-lymphocytes ratio and platelet counts are presented as median values with their respective minimum and maximum ranges using IBM Statistical Package for the Social Sciences (SPSS) Statistics 25.
Based on the analysis of 75 research subjects using IBM SPSS, the ROC curve presented in Figure 1 was From this analysis, it can be concluded that applying the optimal cut-off point of Ou 6.
derived from the intersection curve in Figure 2, yields an AUC of 0.
This indicates a 78.
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Table 2.
Leukocyte and Platelet Profiles.
Parameter .
/uL) Leukocytes Absolute Neutrophil
Count
Absolute Lymphocyte Count
Platelet
Count
NeutrophilLymphocyte Ratio
Medi
Minimu Maxim
Recommen
28,89
4,40-11,50
6,63
1,83
27,44
2,30-8,60
0,98
0,17
5,31
1,62-5,37
7,08
0,39
32,30
0,78-3,53
In Table 3, the study compares the optimal NLR cut-off point (Ou 6.
with the hypothesized NLR cut-off point (Ou 2.
among samples at RSUD Wonosari.
The results demonstrate that a cut-off point of Ou 2.
33 yields a sensitivity of 91.
indicating its ability to correctly identify 91.
2% of true-positive COVID-19 However, specificity at this threshold was only 50%, reflecting a limited capacity to accurately identify negative cases among those without the infection.
The low specificity of 50% at the Ou 2.
33 threshold presents a significant clinical challenge, as it results in a high rate of false-negative cases.
This suggests that half of the patients who do not actually have COVID-19 would be incorrectly identified as positive, leading to unnecessary anxiety and the potential for hospital resource strain.
Sensitivity Diagnostic Test of Neutrophil Lymphocyte Ratio A (Muhammad Ariq Naufal Arofi.
ROC Curve 1 - Specificity Diagonal segments are produced by Area Under the Curve Figure 1.
NLR Receiver Operating Characteristic Curve against RT-PCR.
Series Spesifisitas Point
-,6100
,1500
14,300
16,500
20,500
21,500
24,600
33,500
34,500
43,500
49,100
50,200
63,050
64,800
78,500
89,000
94,500
116,100
125,500
134,500
158,500
185,000
199,500
236,750
279,000
333,000
Sensitivitas Spesifisitas Figure 2.
Sensitivity and Specificity Intersection Curves of NLR to RT-PCR in Covid-19 Patients.
Table 3.
Cut-off Point Diagnostic Test NLR Ou 2.
and RT-PCR Covid-19.
RT-PCR
Total Positive Negative Ou 2.
< 2.
: 52/ .
X100% = 91.
: 9/ .
X100% = 50%
: 52/ .
X100% = 85.
: 9/ .
X100% = 64.
: 91.
2/ .
= 1.
: .
/ 50 = 0.
NLR
Total
Sensitivity Specificity PPV
NPV
LR-
<1500/AAL,
>2500
AAL,
examination neutrophil lymphocyte ratio > 3.
addition, examinations such as platelet counts can examinations such as platelet counts can also be used as a reference.
Other studies also show that According to Ministry of Health of the Republic NLR values Ou 5.
8 increase the likelihood of positive of Indonesia, 2020.
Guidelines for the Prevention RT-PCR results in examining patients with suspected and Control of Coronavirus Disease (COVID-.
can Covid-194 use a hematological examination, namely an BIOMEDIKA.
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According to Gusti et al.
, 2021, the absolute number of neutrophils in Covid-19 patients shows a symptoms from a total of 50 samples.
9 However, dominance of the normal range of 73.
7%, so it is in other studies have revealed that thrombocytopenia line with this study.
5 The absolute number of can occur in Covid-19 because the combination of neutrophils was also found to be within the normal viral infection and mechanical ventilation causes range of 3.
37 103/uL in a study of 1009 Covid-19 patients in Wuhan.
China.
6 The elevation of absolute activation, aggregation and thrombosis in the lungs neutrophil counts in COVID-19 patients is contingent upon the progression of the infection.
This can occur Thrombocytopenic events usually occur in critically when the body's defense by neutrophils causes ill patients who show serious organ damage or Emergency granulopoiesis is a form of blood formation response which will rapidly increase neutrophil production due coagulopathy (DIC).
to infection which directly increases peripheral blood Based on the result shows an increased median NLR of 7.
08 among those infected with COVID-19.
The absolute number of lymphocytes in this study in line with other studies.
NLR in Covid-19 patients has decreased numbers or lymphopenia.
These showed an increase of 4 A 3 and was higher in 16 results are in line with the study by Guan et al.
symptomatic patients with 70.
3 A 13.
5 However, it 2020, where the results of a complete blood count is different in the study by Hayati et al.
, 2022, the in most patients showed lymphopenia .
2%).
dominance of NLR numbers is in the normal range There are several factors that can explain the of 26 people out of a total of 50 samples with a p relationship between Covid-19 and the incidence of value <0.
9 An increase in NLR values can occur Viruses can lyse lymphocytes directly, due to the Sars-COV-2 virus causing severe a cytokine storm that causes lymphocyte apoptosis inflammation and multiple organ damage due to a and atrophy of lymphoid organs, and through the cytokine storm .
This systemic mechanism of lymphocyte exhaustion.
inflammation causes depletion of T lymphocytes.
The explanation regarding the results of platelet T-helper T-suppressor counts with normal ranges in this study is in line with lymphocytes, which is characterized by lymphopenia the study of Hayati et al.
, 2022 which had the results of 46 samples of normal platelet counts from Covid- BIOMEDIKA.
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ymphocyte Diagnostic Test of Neutrophil Lymphocyte Ratio A (Muhammad Ariq Naufal Arofi.
The results of this study, are in line with the release of Reactive Oxygen Species (ROS) such as research of ynzsari et al.
, 2021 with an NLR cut off superoxide radicals and H2O2 which lead to point performance of > 2.
33 having a sensitivity oxidative stress and contribute to the occurrence of value of 75%, specificity of 60%, and AUC at a cytokine storms.
Another factor is the increase in moderate accuracy level of 0.
3 Furthermore, the neutrophils that can be triggered by inflammatory diagnostic utility of the NLR was supported by a cut- factors (IL-1.
IL-6.
TNF-.
IFN-) produced by off point of Ou 2.
23, which demonstrated a sensitivity The main form of human defense 1% and The against viruses depends mainly on lymphocytes, corresponding Area Under the Curve (AUC) was where T helper lymphocyte cells (CD.
and cytotoxic 722, indicating a moderate level of diagnostic T lymphocytes (CD.
are the spearheads of virus 11 However, several other studies had low However, in the process a lymphocyte NLR diagnostic test performance with a weak degree exhaustion mechanism can occur in an unresponsive of accuracy in the range of AUC values of 0.
cell state with persistent antigenic T cell activation in which were conducted in Turkey and in Medan.
In a lung epithelial cells.
This causes T cells to be study in Turkey the performance of the NLR cut off point Ou 2.
4 had a sensitivity value of 69.
01%, a specificity of 65.
40%, and an AUC of 0.
660 at a weak substances such as PD-1 and Tim-3 are biomarkers accuracy level in the total 80 samples used.
12 In the of lymphocyte exhaustion.
7 In addition, several other study in Medan, the performance of the NLR cut off theories such as viruses can lyse lymphocytes point O2.
49 had a sensitivity value of 47.
6%, a directly, cytokine storm which causes lymphocyte specificity of 80%, and an AUC of 0.
638 at a weak apoptosis and lymphoid organ atrophy15, mechanism accuracy level in 87 samples.
13 Another study in of antibody dependent enhancement (ADE)16, as Pakistan tried to test the value of NLR compared to well as lymphocyte dysfunction by the virus are the RT-PCR as an initial diagnostic tool with a cut-off reasons why the NLR value is quite high in Covid-19 point Ou 3.
In 172 patients, a sensitivity value of 17 therefore, the neutrophil lymphocyte ratio 2% and a specificity of 91.
7% were obtained.
during viral inflammation will increase.
However, the The increase in NLR values in Covid-19 patients concept of increasing NLR also applies to several occurs due to the infection process of the Sars-COV- other diseases and is not specific only for Covid-19 2 virus where neutrophils will be activated and Increased NLR can occur in septic degranulate, activated neutrophils will induce the patients, in cases of long-term use of corticosteroids.
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acute cardiac infarction, and other respiratory NLR examination findings.
CONCLUSION
In conclusion, this study validates that the Neutrophil-to-Lymphocyte Ratio (NLR) serves as a reliable and accessible alternative for the early diagnosis of COVID-19 in secondary healthcare The analysis demonstrated a moderate diagnostic accuracy with an AUC of 0.
785 and a statistically significant p-value .
< 0.
95% CI
662Ae0.
At the optimal cut-off point of Ou 305, the NLR achieved a sensitivity of 70.
17% and a specificity of 72.
It is important to note that comorbidities may act as confounding factors by elevating NLR levels in COVID-19 patients.
FUNDING
This research did not receive any external funding REFERENCES