The implications of platelet count changes during hospitalization in the disease management of pediatric patients with bronchiolitis

doi:10.21203/rs.2.17742/v1

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The implications of platelet count changes during hospitalization in the disease management of pediatric patients with bronchiolitis

https://doi.org/10.21203/rs.2.17742/v1

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posted 25 Nov, 2019

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Background: The clinical implications of platelet count changes in patients with bronchiolitis throughout hospitalization have not been extensively investigated. We aimed to investigate the significance of platelet count on admission and platelet count changes during hospitalization in pediatric patients with bronchiolitis.

Methods: Clinical data from 559 consecutive patients hospitalized for bronchiolitis were collected and compared after grouping according to the platelet count on admission and the delta platelet count during hospitalization (the platelet count on discharge minus the platelet count on admission; Group A, delta platelet count ≤ -50 × 109/L; Group B, -50 × 109/L < delta platelet count ≤ 50 × 109/L; Group C, delta platelet count > 50 × 109/L).

Results: Thrombocytosis was found in 122 (21.8%) patients, while 437 (78.2%) patients had a normal platelet count on admission. There was no difference in disease severity between these two groups. Groups A, B, and C comprised 79 (14.1%), 179 (32.0%), and 301 (53.9%) patients, respectively. The patients from Group A had a higher platelet count on admission, a lower platelet count on discharge, and a longer hospitalization duration. These patients had a lower concentration of C-reactive protein, longer periods of oxygen therapy and stay in the pediatric intensive care unit (PICU), and a greater frequency of mechanical ventilation than the patients from Group B or Group C. Notably, among all the patients, the delta platelet count [63 (-3–142) × 109/L] negatively correlated with the numbers of days of oxygen therapy [4.0 (3.0–6.0), day] (r = -0.186, P = 0.027) and stay in the PICU [5.0 (3.0–6.0), day] (r = -0.391, P = 0.001).

Conclusions: Repeated assessment of platelet count during hospitalization in pediatric patients with bronchiolitis may provide useful information for disease management.

Pulmonology

Pediatrics

Platelets count

Bronchiolitis

Disease severity

Bronchiolitis is a disorder most commonly found in infants and young children with viral infections of the lower respiratory tract [1]. Platelets are anucleate blood cells that play a fundamental role in the development of thrombosis and hemostasis. Over the past few years, increasing evidence has validated that the platelet is an important component of the human immune system in response to infection [2–4]. During the process of infection and inflammation, thrombocytes can secrete various substances such as cytokines, procoagulants, oxidants, and antimicrobial peptides, which are involved in beneficial or harmful activities to human health [5–7]. In particular, viral infections often coincide with platelet activation [8].

Previous studies on pediatric patients with bronchiolitis have focused on single platelet count determinations at hospital admission, and these studies found that the prevalence of thrombocytosis on admission ranged from 22.7% to 38.6% among consecutive patients with bronchiolitis [9–11]. The association between thrombocytosis on admission and disease severity in patients with bronchiolitis has been studied [9]. However, the average life span of platelets in blood is 7–10 days. Therefore, during the hospitalization of patients with bronchiolitis, the platelet count may change significantly within the period as a result of altered production and increased destruction and/or sequestration of thrombocytes [7, 8, 11, 12]. To date, the clinical implications of platelet count changes in patients with bronchiolitis throughout hospitalization have not been extensively investigated.

In the present study, we first investigated the association between the platelet count on admission and the clinical characteristics of pediatric patients with bronchiolitis. In addition, we also compared the clinical characteristics and disease severity among these patients grouped by the platelet count changes from admission to discharge.

Study design and patients

In this retrospective observational study, consecutively admitted pediatric patients who were diagnosed with bronchiolitis at the Children’s Hospital of Soochow University (a tertiary teaching hospital in Suzhou, Jiangsu Province, China) between January 2016 and December 2018 were included. Laboratory results, including complete blood count (CBC), were obtained within 6 h after admission. In addition, the CBC results were also determined at least 24 h before discharge, according to the decision of the attending physician. The study flowchart is displayed in Figure 1. Because no patients in this study had a platelet count of less than 100 × 10⁹/L on admission or before discharge, a thrombocytopenia group was not included.

First, the patients were divided into two groups according to the platelet count on admission. Second, in order to analyze the impacts of platelet count changes on the disease severity of hospitalized children with bronchiolitis, the patients were divided into three groups according to the delta platelet count (platelet count on discharge minus platelet count on admission): Group A had a reduction in platelet count, delta platelet count ≤ –50 × 10⁹/L; Group B had a stable platelet count, –50 × 10⁹/L < delta platelet count ≤ 50 × 10⁹/L; and Group C had an increase in platelet count, delta platelet count > 50 × 10⁹/L.

The inclusion criteria were as follows: 1) age ranged from 1 month to 24 months; 2) bronchiolitis was confirmed by the first episode of wheezing, cough, or rhinorrhea (the presence of an upper respiratory tract infection); wheezes or crackles (ausculatory findings); or over-aeration or peribronchial infiltration with or without atelectasis (radiological findings).

Patients were excluded from this study if any of the following conditions were present: 1) immunosuppression; 2) primary hematological disorder (immune thrombocytopenia, leukemia, myelodysplastic syndrome, etc.); 3) active tuberculosis; 4) experienced trauma or surgery within the preceding two weeks; 5) chronic gastrointestinal disorder; 6) premature; 7) congenital heart disease; 8) bronchopulmonary malformation; 9) genetic or neurological disorder.

This study was approved by the Ethics Committee of the Children’s Hospital of Soochow University. Signed consent was obtained from the patients’ guardians.

Data collection and microbiologic evaluation

The demographic information, clinical signs and symptoms, and laboratory findings of the patients were collected. Respiratory syncytial virus, adenovirus, influenza viruses A and B, and parainfluenza viruses 1–3 were detected using direct fluorescent antibody test kits (Chemicon, USA), following the manufacturer’s instructions. Human metapneumovirus was detected by fluorescent real-time polymerase chain reaction (PCR) (BIO-RAD iCycler; Hercules, CA, USA). Rhinovirus was detected using reverse-transcription PCR (BIO-RAD iCycler). Human bocavirus was detected by real-time PCR with nasopharyngeal swab samples. A quantitative diagnostic kit (DaAn Gene Co. Ltd., Guangzhou, China) was used to detect M. pneumoniae DNA. The diagnosis of mycoplasma pneumoniaeinfection was based on both positive PCR and positive IgM findings at admission or at follow-up, or a ≥4-fold rise in the IgG titer, as described previously [13, 14].

Study definitions

The delta platelet count of 50 × 10⁹/L was determined as the cut-off value for the three groups to minimize the chance of misclassification of patients according to known normal variability of platelet counts measured by the counter (XE2000i, Sysmex, Japan) [15–17]. Thrombocytosis was defined as a platelet count > 500 × 10⁹/L, according to the relevant studies [9, 11]. Fever was defined as an axillary temperature exceeding 38.0 °C. The diagnosis of tachypnea was made when the respiratory rate was higher than the World Health Organization value categorized by age; the guidelines were as follows: age 0–2 months, > 60 breaths/min; age 2–12 months, > 50 breaths/min; age 1–5 years, > 40 breaths/min; and age > 5 years, > 20 breaths/min [18]. The disease severity parameters, including the requirement for supplemental oxygen, length of oxygentherapy, admission to the pediatric intensive care unit (PICU), length of stay in the PICU, mechanical ventilation, and length of hospitalization, were recorded [19, 20].

Statistical analysis

Statistical analyses were performed using SPSS 21.0 software (International Business Machines Corporation; Armonk, NY, USA). Data normality was determined by the Kolmogorov–Smirnov test. Continuous variables with non-normal distribution were expressed as the median and interquartile range (25th–75th percentile). Continuous variables with non-normal distribution were analyzed by the Mann–Whitney U-test or the Kruskal–Wallis test. Categorical variables were compared with the chi-squared test or Fisher’s exact test. Correlations between variables were determined by the Spearman correlation. P < 0.05 was considered statistically significant.

A total of 559 consecutive patients were enrolled in this study. The male-to-female ratio of the enrolled patients was 2.45:1. The overall median age was 8 months. A total of 143 (25.6%) patients required supplemental oxygen at the time of admission. Among the 64 (11.4%) patients who were admitted to the PICU, 2 patients were transferred from the ward to the PICU during hospitalization. Seven (1.3%) patients required mechanical ventilation at the time of admission. None of the patients developed thromboembolic or hemorrhagic complications during hospitalization, and all of them reached clinical recovery.

Thrombocytosis was found in 122 (21.8%) patients, while 437 (78.2%) patients had a normal platelet count on admission. The clinical characteristics of the patients grouped according to the platelet count are presented in Table 1. Compared to the patients with a normal platelet count, the patients with thrombocytosis were younger, were less likely to have a fever, and had more days of illness before admission. Of note, although there were more males than females in the study, a lower percentage of the males had thrombocytosis. Regarding the laboratory findings, the patients with thrombocytosis also had a higher peripheral leukocyte count and a lower concentration of C-reactive protein. Moreover, respiratory syncytial virus infection was more frequently documented in patients with thrombocytosis, while human bocavirus was less commonly observed in patients with thrombocytosis (Table 1).

The following characteristics did not differ significantly between the patients with thrombocytosis and the patients with a normal platelet count: occurrence of tachypnea; hemoglobin level; length of oxygentherapy; admission rate to the PICU; length of stay in the PICU; requirement for supplemental oxygen or mechanical ventilation; length of hospitalization; and rates of infection for human metapneumovirus, rhinovirus, influenza virus A/B, parainfluenza virus 1/2/3, adenovirus, and mycoplasma pneumoniae (Table 1).

Group A, Group B, and Group C comprised 79 (14.1%), 179 (32.0%), and 301 (53.9%) patients, respectively. The median delta platelet counts in Group A, Group B, and Group C were –99 (ranged from –344 to –50) × 10⁹/L, 7 (ranged from –48 to 50) × 10⁹/L, and 133 (ranged from 51 to 711) × 10⁹/L, respectively. The clinical characteristics of the patients grouped by the delta platelet count are presented in Table 2. Compared to the patients with a stable platelet count (Group B) and the patients with an increased platelet count (Group C), the patients with a decreased platelet count (Group A) had a longer duration between platelet count measurements and a lower C-reactive protein level. Regarding the parameters on disease severity, the patients in Group A had a longer length of oxygentherapy, a longer length of stay in the PICU, a longer length of hospitalization, and more frequent use of mechanical ventilation than the patients in Group B (all P < 0.05) or Group C (all P < 0.05). Moreover, the patients in Group A were younger (P = 0.006), had a lower occurrence of fever (P < 0.001), and had a higher peripheral leukocyte count (P = 0.001) than the patients in Group C. Furthermore, the patients in Group C had a lower platelet count on admission (P < 0.001), a higher platelet count on discharge (P < 0.001), a more frequent occurrence of fever (P < 0.001), a lower peripheral leukocyte count (P = 0.003), a higher concentration of C-reactive protein (P = 0.046), and a lower infection rate of rhinovirus (P = 0.004) than the patients in Group B (Table 2).

The following characteristics did not differ significantly among the three groups: gender ratio; number of days of illness before admission; occurrence of tachypnea or hemoglobin; rate of requiring supplemental oxygen; admission rate to the PICU; infection rates of respiratory syncytial virus, human metapneumovirus, human bocavirus, influenza virus A/B, parainfluenza virus 1/2/3, adenovirus, and mycoplasma pneumoniae (Table 2).

Next, we further evaluated the associations between the delta platelet count and the parameters of disease severity. We identified that the delta platelet count [63 (–3–142) × 10⁹/L] was negatively correlated with the length of oxygentherapy [4.0 (3.0–6.0), day] (r = –0.186, P = 0.027) as well as the length of stay in the PICU [5.0 (3.0–6.0), day] (r = –0.391, P = 0.001) (Figure 2).

The present study demonstrated that the prevalence of thrombocytosis on admission among pediatric patients with bronchiolitis was 21.8%, which is consistent with the report by Zheng, et al. [11]. We first compared the clinical characteristics between the patients with thrombocytosis and the patients with a normal platelet count on admission. We validated the findings of a previous report that the patients with thrombocytosis were younger than the patients with a normal platelet count and that there was no difference in disease severity between the two groups [9]. It has been reported previously that the platelet count peaks during the second and third weeks of the illness [21]. However, in the present study, the median duration of illness before admission in the thrombocytosis group was 5 days. The reason for this discrepancy between studies might be that the bone marrow precursor cells of young patients are more sensitive to external stimuli such as infections and inflammation than those of older patients [22]. We also demonstrated that respiratory syncytial virus infection was more frequently documented in the patients with thrombocytosis, which is in agreement with the results of previous studies [10, 11]. Human bocavirus infection was less commonly documented in the patients with thrombocytosis, which has not been described previously; therefore, further research must be performed on the relationship between this type of infection and thrombocytosis in pediatric patients with bronchiolitis.

The first novel aspect of the present study is the observation that the patients with a normal platelet count on admission more often presented with a fever and had higher C-reactive protein levels than the patients with thrombocytosis. The reason for this difference might be that immune responses to stimulation are more vigorous in older patients, as immunity improves with age in young patients. Our study also demonstrated that a lower percentage of male patients were in the thrombocytosis group compared with the normal platelet count group, but the exact underlying mechanisms are unclear and warrant further investigations.

Another novel finding is the observation that changes of platelet count during hospitalization, even for the patients whose platelet counts remained within the normal range, were associated with age, the severity of bronchiolitis, and laboratory abnormalities. The patients with a decreased platelet count were younger and had a more severe disease status than the patients with an increased or a stable platelet count. The decrease in platelet count after hospitalization in our patients indicated a poor compensatory response of the host immune cells to infection. Activated platelets can secrete various substances, including kinocidins, the chemokine (C-X-C motif) ligand 4, the chemokine (C-C motif) ligand 5, the chemokine (C-C motif) ligand 3, and other microbicidal components, which contribute to the clearance of viruses [8]. Thus, the reduction in platelet count might result in impaired antivirus effects during infection in patients.

Perhaps the most important novelty of the present study is the demonstration that the delta platelet count was negatively correlated with the length of oxygentherapy and the length of stay in the PICU. Thus, assessment of dynamic platelet count changes in patients hospitalized for bronchiolitis may help risk stratification and medical prognostication, as well as provide important information for disease management.

There are several limitations associated with the present study that must be mentioned. First, our findings were derived from a single medical center, and they might not be applicable to patients in other areas. A multi-center study is necessary in the future. Second, existing selection bias might be present in this study due to the inherent features of its retrospective design. Third, no patients in this study had a platelet count less than 100 × 10⁹/L on admission or before discharge. Thus, the results might not be representative of the overall population of bronchiolitis patients.

In conclusion, changes in platelet count over time are common among hospitalized pediatric patients with bronchiolitis. Our study demonstrates that a decrease in platelet count is associated with disease severity. Repeated assessment of the platelet count during the hospitalization of patients with bronchiolitis may provide useful information on disease management.

Abbreviations

PICU: pediatric intensive care unit;

CBC: complete blood count;

IQR: interquartile range;

PC: platelet count.

Ethics approval and consent to participate

This study was approved by the Ethics Committee of the Children’s Hospital of Soochow University. Signed consent was obtained from the patients’ guardians.

Consent for publication

Not applicable.

Availability of data and materials

The data that support the findings of this study are available from the corresponding author (ZRC) upon reasonable request.

Competing interests

The authors declare that they have no competing interests.

Funding

This study was funded by the Livelihood science and technology of Suzhou (Huiming Sun, Grant SYS201640); National Natural Science Foundation of China (Huiming Sun, Grant 81900006); National Natural Science Foundation of China (Yongdong Yan, Grant 81870006); Special support for diagnosis and treatment technology of clinical key disease in Suzhou (Canhong Zhu, Grant 201809). The funding bodies had no roles in study design, data collection and analysis, decision to publish or preparation of the manuscript.

Authors’ contributions

HMS and WJ and ZRC were responsible for the study design, literature search and manuscript drafting. HMS and HX and TW were responsible for the data collection and statistical analysis. HMS and ZRC were mainly responsible for the data interpretation. CLH and YQW and YDY were responsible for the study concept and critical revision. All authors contributed to the discussion, writing and reviewing the manuscript and all authors have approved the final manuscript.

Acknowledgements

The authors would like to thank Shuxiang Li for her assistance in statistical analysis of the results.

1.American Academy of Pediatrics Subcommittee on D, Management of B: Diagnosis and management of bronchiolitis. Pediatrics 2006, 118(4):1774–1793.

2.Yeaman MR: The role of platelets in antimicrobial host defense. Clinical infectious diseases: an official publication of the Infectious Diseases Society of America 1997, 25(5):951–968; quiz 969–970.

3.Fitzgerald JR, Foster TJ, Cox D: The interaction of bacterial pathogens with platelets. Nat Rev Microbiol 2006, 4(6):445–457.

4.Elzey BD, Sprague DL, Ratliff TL: The emerging role of platelets in adaptive immunity. Cell Immunol 2005, 238(1):1–9.

5.Yeaman MR, Bayer AS: Antimicrobial peptides versus invasive infections. Curr Top Microbiol Immunol 2006, 306:111–152.

6.Ware J, Corken A, Khetpal R: Platelet function beyond hemostasis and thrombosis. Curr Opin Hematol 2013, 20(5):451–456.

7.Kamath S, Blann AD, Lip GY: Platelet activation: assessment and quantification. Eur Heart J 2001, 22(17):1561–1571.

8.Assinger A: Platelets and infection - an emerging role of platelets in viral infection. Front Immunol 2014, 5:649.

9.Al Shibli A, Alkuwaiti N, Hamie M, Abukhater D, Noureddin MB, Amri A, Al Kaabi S, Al Kaabi A, Harbi M, Narchi H: Significance of platelet count in children admitted with bronchiolitis. World J Clin Pediatr 2017, 6(2):118–123.

10.Bilavsky E, Yarden-Bilavsky H, Shouval DS, Fisch N, Garty BZ, Ashkenazi S, Amir J: Respiratory syncytial virus-positive bronchiolitis in hospitalized infants is associated with thrombocytosis. Isr Med Assoc J 2010, 12(1):39–41.

11.Zheng SY, Xiao QY, Xie XH, Deng Y, Ren L, Tian DY, Luo ZX, Luo J, Fu Z, Huang AL et al: Association between secondary thrombocytosis and viral respiratory tract infections in children. Sci Rep 2016, 6:22964.

12.Kaushansky K: The molecular mechanisms that control thrombopoiesis. J Clin Invest 2005, 115(12):3339–3347.

13.Jiang W, Wu M, Zhou J, Wang Y, Hao C, Ji W, Zhang X, Gu W, Shao X: Etiologic spectrum and occurrence of coinfections in children hospitalized with community-acquired pneumonia. BMC Infect Dis 2017, 17(1):787.

14.Sun H, Chen Z, Yan Y, Huang L, Wang M, Ji W: Epidemiology and clinical profiles of Mycoplasma pneumoniae infection in hospitalized infants younger than one year. Respir Med 2015, 109(6):751–757.

15.Ross DW, Ayscue LH, Watson J, Bentley SA: Stability of hematologic parameters in healthy subjects. Intraindividual versus interindividual variation. Am J Clin Pathol 1988, 90(3):262–267.

16.Gorelik O, Izhakian S, Barchel D, Almoznino-Sarafian D, Tzur I, Swarka M, Beberashvili I, Feldman L, Cohen N, Shteinshnaider M: Prognostic significance of platelet count changes during hospitalization for community-acquired pneumonia. Platelets 2017, 28(4):380–386.

17.Shteinshnaider M, Barchel D, Almoznino-Sarafian D, Tzur I, Tsatsanashvili N, Swarka M, Cohen N, Gorelik O: Clinical characteristics and prognostic significance of changes in platelet count in an internal medicine ward. Eur J Intern Med 2014, 25(7):646–651.

18.Bradley JS, Byington CL, Shah SS, Alverson B, Carter ER, Harrison C, Kaplan SL, Mace SE, McCracken GH, Jr., Moore MR et al: The management of community-acquired pneumonia in infants and children older than 3 months of age: clinical practice guidelines by the Pediatric Infectious Diseases Society and the Infectious Diseases Society of America. Clin Infect Dis 2011, 53(7):e25–76.

19.Sheeran P, Jafri H, Carubelli C, Saavedra J, Johnson C, Krisher K, Sanchez PJ, Ramilo O: Elevated cytokine concentrations in the nasopharyngeal and tracheal secretions of children with respiratory syncytial virus disease. The Pediatric infectious disease journal 1999, 18(2):115–122.

20.Garcia CG, Bhore R, Soriano-Fallas A, Trost M, Chason R, Ramilo O, Mejias A: Risk factors in children hospitalized with RSV bronchiolitis versus non-RSV bronchiolitis. Pediatrics 2010, 126(6):e1453–1460.

21.Ishiguro A, Suzuki Y, Mito M, Shimbo T, Matsubara K, Kato T, Miyazaki H: Elevation of serum thrombopoietin precedes thrombocytosis in acute infections. Br J Haematol 2002, 116(3):612–618.

22.Matsubara K, Fukaya T, Nigami H, Harigaya H, Hirata T, Nozaki H, Baba K: Age-dependent changes in the incidence and etiology of childhood thrombocytosis. Acta Haematol 2004, 111(3):132–137.

Table 1. Comparison of the clinical characteristics of patients grouped by platelet count on admission.

Parameter	Thrombocytosis group (n = 122)	Normal platelet count group (n = 437)	P
General characteristics
Age, median (IQR), months	4.0 (2.0–6.0)	8.0 (2.5–14.0)	<0.001
Male, n (%）	76 (62.3)	321 (73.5)	0.016
Platelet count on admission, median (IQR), × 10⁹/L	567.5 (526.5–594.0)	360.0 (292.0–427.5)	<0.001
Days of illness before admission, median (IQR), days	5.0 (3.75–7.0)	4.0 (3.0–5.0)	<0.001
Clinical signs and symptoms
Fever, n (%)	28 (22.9)	192 (43.9)	<0.001
Tachypnea, n (%)	23 (18.9)	91 (20.8)	0.633
Laboratory findings on admission
Peripheral leukocyte count, median (IQR), × 10⁹/L	13.14 (9.56–16.47)	9.68 (7.05–12.85)	<0.001
Hemoglobin, median (IQR), g/L	115.5 (109.0–125.0)	118.0 (108.0–126.0)	0.285
C-reactive protein, median (IQR), mg/dL	1.17 (0.33–5.51)	1.78 (0.52–9.53)	0.028
Disease severity
Requirement for supplemental oxygen, n (%)	31 (25.4)	112 (25.6)	0.961
Length of oxygen therapy, median (IQR), days	4.0 (3.0–5.25)	4.0 (3.0–6.0)	0.624
Admission to the PICU, n (%)	10 (8.2)	54 (12.4)	0.202
Length of stay in PICU, median (IQR), days	6.0 (2.0–6.0)	5.0 (3.0–6.75)	0.973
Mechanical ventilation, n (%)	2 (1.6)	5 (1.1)	0.650
Length of hospitalization, median (IQR), days	8.0 (7.0–10.0)	8.0 (7.0–10.0)	0.352
Pathogens
Respiratory syncytial virus, n (%)	48 (39.3)	102 (23.3)	<0.001
Human metapneumovirus, n (%)	1 (0.8)	9 (2.1)	0.699
Rhinovirus, n (%)	28 (22.9)	72 (16.5)	0.099
Human bocavirus, n (%)	5 (4.1)	47 (10.8)	0.025
Influenza virus A, n (%)	1 (0.8)	4 (0.9)	>0.999
Influenza virus B, n (%)	0 (0)	0 (0)	/
Parainfluenza virus 1, n (%)	0 (0)	2 (0.5)	>0.999
Parainfluenza virus 2, n (%)	0 (0)	0 (0)	/
Parainfluenza virus 3, n (%)	4 (3.3)	14 (3.2)	>0.999
Adenovirus, n (%)	0 (0)	3 (0.7)	>0.999
Mycoplasma pneumoniae, n (%)	25 (20.5)	93 (21.3)	0.850

IQR, interquartile range; PICU, pediatric intensive care unit.

Table 2. Comparison of the clinical characteristics of patients grouped by the delta platelet count.

Parameter	Group A (Decreased PC) (n = 79)	Group B (Stable PC) (n = 179)	Group C (Increased PC) (n = 301)	P
General characteristics
Age, median (IQR), months	4.0 (2.0–11.0) ^a	6.0 (2.0–12.0)	7.0 (3.0–14.0)	0.018
Male, n (%）	52 (65.8)	120 (67.0）	225 (74.8)	0.108
Platelet count on admission, median (IQR), × 10⁹/L	492.0 (414.0–577.0) ^ab	426.0 (339.0–524.0)	354.0 (278.0–440.5) ^c	<0.001
Platelet count on discharge, median (IQR), × 10⁹/L	357 (302–464) ^ab	436 (350–542)	529 (435.5–590) ^c	<0.001
Days of illness before admission, median (IQR), days	5.0 (3.0–6.0)	4.0 (3.0–6.0)	4.0 (3.0–5.0)	0.506
Duration between Platelet count measurements, median (IQR), days	7.0 (6.0–10.0)^ab	7.0 (6.0–9.0)	7.0 (6.0–9.0)	0.039
Clinical signs and symptoms
Fever, n (%)	19 (24.1) ^a	54 (30.2)	147 (48.8) ^c	<0.001
Tachypnea, n (%)	22 (27.8)	34 (19.0)	58 (19.3)	0.207
Laboratory findings on admission
Peripheral leukocyte count, median (IQR), × 10⁹/L	11.48 (8.84–15.12) ^a	10.76 (7.96–14.25)	9.70 (6.95–12.93) ^c	<0.001
Hemoglobin, median (IQR), g/L	120 (112–128)	117 (108–127)	117 (108–123)	0.132
C-reactive protein, median (IQR), mg/dL	0.87 (0.25–3.48) ^ab	1.46 (0.47–7.52)	2.93 (0.63–10.57) ^c	<0.001
Disease severity
Requirement for supplemental oxygen, n (%)	23 (29.1)	47 (26.3)	73 (24.3)	0.657
Length of oxygen therapy, median (IQR), days	6.0 (3.75–10.75) ^ab	4.0 (3.0–6.0)	4.0 (3.0–5.0)	0.002
Admission to the PICU, n (%)	15 (19.0)	21 (11.7)	28 (9.3)	0.055
Length of stay in PICU, median (IQR), days	7.0 (6.0–9.0) ^ab	5.0 (4.0–6.0)	4.0 (3.0–6.0)	<0.001
Mechanical ventilation, n (%)	5 (6.3) ^ab	1 (0.6)	1 (0.3)	0.001
Length of hospitalization, median (IQR), days	8.0 (7.0–11.0)^ab	8.0 (7.0–10.0)	8.0 (7.0–10.0)	0.038
Pathogens
Respiratory syncytial virus, n (%)	26 (32.9)	44 (24.6)	80 (26.6)	0.375
Human metapneumovirus, n (%)	0 (0)	2 (1.1)	8 (2.7)	0.293
Rhinovirus, n (%)	16 (20.3)	43 (24.0)	41 (13.6) ^c	0.013
Human bocavirus, n (%)	9 (11.4)	17 (9.5)	26 (8.6)	0.750
Influenza virus A, n (%)	0 (0)	0 (0)	5 (1.7)	0.176
Influenza virus B, n (%)	0 (0)	0 (0)	0 (0)	/
Parainfluenza virus 1, n (%)	0 (0)	0 (0)	2 (0.7)	0.655
Parainfluenza virus 2, n (%)	0 (0)	0 (0)	0 (0)	/
Parainfluenza virus 3, n (%)	1 (1.3)	3 (1.7)	14 (4.7)	0.152
Adenovirus, n (%)	0 (0)	0 (0)	3 (1.0)	0.555
Mycoplasma pneumoniae, n (%)	22 (27.8)	30 (16.8)	66 (21.9)	0.116

PC, platelet count; IQR, interquartile range; PICU, pediatric intensive care unit;

^aGroup A (Drop in PC) vs. Group C (Rise in PC), P < 0.05;

^b Group A (Drop in PC) vs. Group B (Stable PC), P < 0.05;

^c Group C (Rise in PC) vs. Group B (Stable PC), P < 0.05.

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The implications of platelet count changes during hospitalization in the disease management of pediatric patients with bronchiolitis

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Abstract

Figures

Background

Methods

Study design and patients

Data collection and microbiologic evaluation

Study definitions

Statistical analysis

Results

Discussion

Conclusions

Declarations

Abbreviations

Ethics approval and consent to participate

Consent for publication

Availability of data and materials

Competing interests

Funding

Authors’ contributions

Acknowledgements

References

Tables

Status:

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