Association between ABO blood group and blood component transfusion requirements in dengue infection: a retrospective study from a tertiary hospital in Kerala, India

Abstract

Objective

Platelet and fresh frozen plasma (FFP) transfusions are routinely employed in the management of severe dengue. Previous research has indicated a potential link between ABO blood groups and susceptibility to dengue, with evidence suggesting that mosquito vector feeding preferences may be influenced by host blood type. These factors could potentially impact transfusion demands during outbreaks. This retrospective study aimed to investigate the relationship between ABO blood groups and transfusion requirements in patients with dengue.

Design

Retrospective study.

Setting

The study was conducted at a tertiary care hospital in Kerala.

Methods

Clinical and laboratory data were reviewed for 199 patients confirmed with dengue who received blood component transfusions and compared with two control groups: 200 randomly selected patients with dengue who did not require transfusions and 200 patients without dengue who required transfusions, over a period spanning January 2015 to March 2023.

Results

Among transfused dengue cases, blood groups O (41.71%), A (28.14%) and B (23.12%) were most prevalent; however, no statistically significant association was observed between ABO blood group and transfusion requirement. Furthermore, the total volumes of FFP and platelet transfusions did not differ significantly across ABO groups among patients with dengue. Notably, platelet transfusions were significantly more frequent in dengue cases (92.0%) compared with transfused patients without dengue (35.5%), whereas FFP transfusions were more common in non-dengue transfused cases (84.5%) than in patients with dengue (44.7%). Patients with dengue also received significantly higher mean volumes of both FFP and platelets.

Conclusion

Despite earlier reports linking ABO blood types to dengue susceptibility, this study found no significant association with transfusion requirements, warranting confirmation through larger multicentre studies.

STRENGTHS AND LIMITATIONS OF THIS STUDY.

• Retrospective study design with clearly defined dengue cases and transfusion records.

• Use of two control groups for comparison: non-transfused patients with dengue and transfused patients without dengue.

• Random sampling ensured comparability and reduced selection bias.

• Exclusion of paediatric patients minimised confounding related to age-specific transfusion practices.

• Lack of cryoprecipitate data limited comprehensive evaluation of all blood components.

Introduction

Dengue, caused by the flavivirus, is a widespread arthropod-borne disease with substantial global ramifications.¹ Dengue fever is caused by dengue viruses, single-stranded enveloped RNA viruses transmitted mainly by Aedes mosquitoes like Aedes aegypti and A. albopictus.² Dengue fever presents as an acute infectious disease marked by fever, myalgia, headache and joint pain, progressing through febrile, critical and convalescent phases, with severe forms like dengue haemorrhagic fever and dengue shock syndrome involving vascular dysfunction and multi-organ involvement.³

Genetic factors, including ABO blood groups, play a significant role in influencing immune responses and susceptibility to infectious diseases.^{4 5} The potential impact of the ABO blood group system on dengue pathogenesis has prompted several investigations examining its association with disease acquisition and severity.^{6 7} The antigens in the ABO blood group system are composed of carbohydrates,⁸ and the glycosylated epitopes of the dengue virus elicit IgM antibodies that may cross-react with similar glycosylated structures on host cells.⁹ Higher levels of von Willebrand factor and lower levels of ADAMTS13 in certain blood groups have been linked to variations in disease severity in dengue.^{10 11} Studies on Aedes species vectors have also shown a feeding preference for specific blood groups, which may influence the risk of dengue transmission.^{12 13}

The surge in severe dengue cases during an epidemic necessitates a higher demand for platelets and fresh frozen plasma (FFP).¹⁴ This elevated demand can lead to the suboptimal utilisation of blood components, imposing significant pressure on blood centres to manage their inventory efficiently during dengue outbreaks. Identifying whether specific blood groups are more predisposed to requiring blood component transfusions during such outbreaks in particular regions would be essential knowledge for blood banks. This information would enable more strategic planning and resource allocation, ultimately enhancing the overall management of blood supplies during dengue epidemics.¹⁵ In the study catchment area, the ABO distribution among blood donors has been reported as O 37.86%, B 29.10%, A 26.27%, and AB 6.77%.¹⁶

Thrombocytopenia in dengue arises from impaired megakaryopoiesis due to dysfunction of haematopoietic progenitor and stromal cells, autoimmune-mediated platelet clearance and platelet adherence to dengue virus-infected endothelial cells.^{17 18} Studies indicate that patients with dengue may require platelet transfusions, particularly when platelet counts fall below 50×10⁹/L,¹⁹ though the effectiveness of such transfusions remains controversial.²⁰ In severe cases, supplementing ADAMTS13 with FFP or cryosupernatant can mitigate platelet sequestration by endothelial cells and manage coagulopathy associated with transaminitis.¹¹

Investigating correlations between ABO blood groups and blood component transfusion requirements in dengue cases remains an underexplored area, necessitating further research to fill this crucial knowledge gap. Therefore, our study intended to examine the association between the ABO blood group and the requirement for FFP and platelet transfusions among patients with dengue.

Methods

Study design

This retrospective study was conducted at Central Research Laboratory, Believers Church Medical College Hospital, Thiruvalla, Kerala, India.

Data sources and collection

Data was collected for demographic, platelet and FFP transfusion details. Dengue test results were collected from the records of the Medical Records Department of Believers Church Medical College Hospital, Kerala, India. Red blood cell and whole blood transfusion data were not collected, as per our institutional protocol for dengue management. Transfusion support in dengue primarily involves platelet and plasma components due to thrombocytopenia and coagulopathy. Red blood cell or whole blood transfusions are rarely indicated in these patients unless associated with other conditions such as major bleeding or trauma, and no such cases were encountered in our study cohort.

Cases and controls

The case group (Group I) included adult participants who were positive for the dengue NS1 antigen or anti-dengue IgM antibodies and received platelet or FFP transfusions. Dengue infection was diagnosed either by an immunochromatographic card test (Dengue Day 1 Test, J. Mitra & Co, New Delhi, India) or by qualitative detection of dengue IgM antibodies using the Dengue IgM Microlisa (MAC IgM) capture ELISA (J. Mitra & Co., India). This assay enables qualitative detection of NS1 antigen and differential detection of IgM and IgG antibodies in human serum. All procedures and interpretations were performed strictly according to the manufacturer’s instructions. The control group (Group II) consisted of adult participants who were positive for the dengue NS1 antigen and anti-dengue IgM antibodies but did not receive any transfusions. All controls were admitted to the internal medicine wards or the intensive care unit of the same hospital during the same study period as the transfused group, ensuring comparability of clinical settings, management practices and transfusion protocols. A third group (Group III) was included, consisting of adult participants who received platelet or FFP transfusions for conditions other than dengue (eg, trauma, gastrointestinal bleeding), serving as a comparison group for transfusion characteristics.

Inclusion and exclusion criteria

Clinical and laboratory data were analysed from 199 Group I patients who are dengue-positive and underwent blood component transfusion between January 2015 and March 2023. Additionally, 200 randomly selected Group II patients with dengue who did not receive transfusions were included to assess the association. These 200 patients were selected using simple random sampling; a list of all eligible patients who were dengue-positive without transfusion during the study period was generated from hospital records, and a computer-generated random number list was used to select the required sample. Group III, consisting of randomly selected transfused patients without dengue, was also analysed within the same timeframe (figure 1). Only adult patients (≥18 years) were included in all three groups. Paediatric patients (<18 years) and those with haematological malignancies were excluded from the study.

Figure 1. Flowchart illustrating the selection and grouping of study participants based on dengue status and transfusion history (January 2015 to March 2023). This flowchart outlines the classification of participants into three study groups based on medical records from January 2015 to March 2023. Group I: Patients who are dengue-positive and received transfusion (platelets, FFP or both). Group II: Patients who are dengue-positive and did not require transfusion. Group III: Patients who are dengue-negative and received transfusion (platelets, FFP or both). Data were extracted from hospital records, and subjects were selected based on inclusion criteria and random sampling where applicable.

Sample size calculation

The study’s sample size was determined based on the previous report by Ravichandran et al.²¹ This study reported a higher proportion of dengue fever among individuals with AB blood group compared with controls, with an OR of 0.4084. The calculated sample size was 400 (200 cases and 200 controls) to ensure 80% power and a 95% CI. This calculation was performed using OpenEpi V.3.0.

Statistical analysis

Demographic, clinical and biochemical characteristics of Group I (dengue cases with transfusion) and Group II were summarised using appropriate descriptive statistics. The association between ABO blood groups and transfusion requirements was evaluated using χ² tests, and ORs with 95% CIs were calculated. Comparisons involving patients with dengue with and without transfusion (Group II) and transfused patients without dengue (Group III) were performed using Mann-Whitney U test for continuous variables and χ² tests for categorical variables. The relationship between ABO blood groups and transfusion volume was assessed using the Kruskal-Wallis test. A p value <0.05 was regarded as statistically significant. All statistical analyses were performed using SPSS V.2.0.

Patient and public involvement

None

Blood component administration policy

All blood component transfusions were carried out according to the national transfusion guidelines, with all components screened for transfusion-transmitted infections. Platelet and FFP units were selected to be ABO-compatible with the recipient. Type-identical components were provided whenever available; however, due to inventory constraints, ABO-compatible but not always type-identical components were sometimes administered. Transfusion triggers were based on clinical assessment and laboratory parameters, with platelet transfusions typically administered for counts <10 000/µL in the absence of bleeding or <20 000/µL with risk factors for bleeding. FFP was administered to patients with coagulopathy and active bleeding or prior to invasive procedures.

Results

Study group characteristics of cases and controls

The study included 399 participants, consisting of 199 patients with dengue who required transfusion (Group I, 49.87%) and 200 controls (Group II, 50.13%) based on predefined criteria. The mean age in the transfused study group was 53.37±16.25 years, while in the non-transfused dengue group, it was 55.55±17.02 years, and it was comparable (p=0.340, table 1). Males were significantly more prone to transfusion among patients with dengue (p=0.024, table 1). Liver enzyme levels (aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase) and total leucocyte and platelet count were significantly elevated in patients with dengue who required transfusion compared with those who did not (p<0.05, table 1). Additionally, significant differences in renal function markers (urea and creatinine) and protein levels (total protein and albumin) were identified between the groups (p<0.05, table 1).

Table 1. Comparison of demographic, clinical and biochemical parameters between patients with dengue with and without transfusion.

Characteristics	Dengue with transfusion (n=199)	Dengue without transfusion (n=200)	χ2/t-value	P value
Age (years), mean (SD)	53.37 (16.26)	51.91 (14.36)	0.95	0.340
Male sex, n (%)	116 (58.29)	94 (47.00)	4.658	0.024*
Abdominal pain, n (%)	15 (7.5)	25 (12.5)	2.201	0.099
Vomiting, n (%)	37 (18.6)	53 (26.5)	3.132	0.059
Headache, n (%)	44 (22.1)	54 (27.0)	1.037	0.257
AST U/L (mean±SD)	680.45±2842.14	181.48±169.16	2.472	0.028*
ALP U/L (mean±SD)	116.80±98.72	91.41±47.05	3.277	0.021*
ALT U/L (mean±SD)	314.34±1035.09	112.07±100.88	2.744	0.015*
Total protein g/dL (mean±SD)	6.08±0.81	6.47±0.54	−5.656	<0.001**
Albumin g/dL (mean±SD)	3.27±0.55	3.60±0.44	−6.616	<0.001**
Urea mg/dL (mean±SD)	34.64±36.49	21.11±12.61	4.945	<0.001**
Creatinine mg/dL (mean±SD)	1.32±2.07	0.89±0.36	2.887	0.006**
WBC count cells/mm3 (mean±SD)	5879.64±4695.21	4730.85±3281.23	2.831	0.006**
Platelet count 10³/μL (mean±SD)	0.27±0.27	0.73±0.90	−6.775	<0.001*
Hb g/dL (mean±SD)	13.71±2.79	14.03±1.64	−1.396	0.184
RBC count 10⁶/μL (mean±SD)	4.80±0.996	4.84±0.575	−0.491	0.661

Data are presented as mean±SD for continuous variables and number (percentage) for categorical variables. Independent t-test was used for continuous variables and χ2 test for categorical variables.

t-values used for continuous variables; χ² values for categorical variables.

*p<0.05; **p<0.01.

ALP, alkaline phosphatase; ALT, alanine aminotransferase; AST, aspartate aminotransferase; Hb, haemoglobin; RBC, red blood cell; WBC, white blood cell.

Association of ABO blood group with transfusion in patients with dengue

Among patients with dengue, blood group O (41.71%) had the highest transfusion rate, followed by blood groups A (28.14%), B (23.12%) and AB (7.04%). Analysis based on ABO blood group distribution revealed no significant association between blood group and transfusion status in patients with dengue. Blood group O was transfused most often, while blood group AB had the fewest transfusions (table 2). Additionally, a sex-stratified analysis of ABO blood groups and transfusion status (transfused vs non-transfused) did not show any statistically significant differences (table 3).

Table 2. Association of ABO blood group between patients with dengue with and without transfusion.

Blood group	Dengue with transfusion n (%)	Dengue without transfusion n (%)	χ2	P value*	OR (95% CI)
A	56 (28.14)	47 (23.5)	1.12	0.291	1.27 (0.81 to 2.00)
B	46 (23.12)	53 (26.5)	0.217	0.434	0.834 (0.53 to 1.32)
AB	14 (7.04)	9 (4.5)	1.18	0.278	1.604 (0.67 to 3.96)
O	83 (41.71)	91 (45.50)	0.583	0.445	0.857 (0.576 to 1.275)

^*χ2 test.

Table 3. Sex-stratified analysis between ABO blood group and dengue.

	Males					Female
	Dengue with transfusion n (%)	Dengue without transfusion n (%)	χ2	P value*	OR (95% CI)	Dengue with transfusion n (%)	Dengue without transfusion n (%)	χ2	P value*	OR (95% CI)
A	35 (30.17)	23 (24.47)	0.612	0.221	1.52 (0.78 to 2.98)	21 (25.30)	24 (22.64)	0.138	0.886	1.05 (0.51 to 2.17)
B	30 (25.86)	23 (24.47)	0.04	0.447	1.30 (0.66 to 2.59)	16 (19.28)	30 (28.30)	1.558	0.242	0.64 (0.31 to 1.34)
AB	7 (6.03)	4 (4.26)	0.314	0.398	1.75 (0.48 to 6.41)	7 (8.43)	5 (4.72)	1.013	0.402	1.69 (0.50 to 5.73)
O	44 (37.93)	44 (46.81)	1.681	0.195	0.70 (0.39 to 1.21)	39 (46.99)	47 (44.34)	0.132	0.717	1.11 (0.62 to 1.99)

^*χ2 test.

The distribution of transfusion requirements across different blood groups

The analysis of transfusion requirements among patients with dengue across different ABO blood groups revealed no statistically significant association between blood type and the volume of FFP or platelet transfusions (table 4). Blood group A had the highest mean FFP transfusion volume (1.75±2.40 units), whereas blood group O had the lowest mean FFP transfusion volume (1.02±1.70 units). However, the difference was not statistically significant (p=0.0929). For platelet transfusions, blood group B received the highest mean number of transfused units (6.11±4.96) with a median of 4 units (IQR: 3–8), while blood group O had the lowest mean platelet transfusion volume (4.57±3.75) with a median of 4 units (IQR: 3–6). Again, the differences across blood groups were not statistically significant (p=0.2215).

Table 4. Association between FFP and platelet transfusion volume (in units) with ABO blood type in dengue.

Blood group	FFP				Platelets
	Mean (SD)	Median (IQR)	P value*	Test statistic	Mean (SD)	Median (IQR)	P value*	Test statistic
A	1.75 (2.40)	1 (0–2)	0.0929	5.5	4.11 (2.44)	4 (3–5)	0.2215	4.5
B	1.72 (2.26)	1 (0–3)			6.11 (4.96)	4 (3–8)
AB	1.07 (1.69)	0 (0–2)			4.93 (2.56)	4.5 (3–7)
O	1.02 (1.70)	0 (0–2)			4.57 (3.75)	4 (3–6)

^*Kruskal-Wallis test.

FFP, fresh frozen plasma.

Transfusion characteristics among dengue cases compared with non-dengue transfused cases

The distribution of age and sex in both groups was comparable (p>0.05). As shown in table 5, the frequency of FFP transfusion was significantly lower in patients with dengue requiring transfusion compared with non-dengue transfused cases (44.7% vs 84.5%, p<0.001). In contrast, platelet transfusion was significantly more common in transfused patients with dengue than in non-dengue-transfused group III cases (92.0% vs 35.5%, p<0.001). The simultaneous transfusion of FFP and platelets was also significantly higher in transfused patients with dengue than in non-dengue-transfused cases (36.7% vs 20.0%, p<0.001). The mean transfusion volumes for FFP and platelets in transfused patients with dengue were 1.39 units and 4.81 units, respectively, whereas in non-dengue transfused cases, they were 4.15 units and 1.98 units, respectively (p<0.001). Review of daily blood bank inventory logs during the study period confirmed adequate availability of platelet and FFP units, indicating that these differences were attributable to clinical indications rather than supply limitations.

Table 5. Transfusion characteristics among dengue cases compared to non-dengue transfused cases.

Transfusion characteristics	Dengue with transfusion n (%)	Non-dengue with transfusion n (%)	Test statistic	P value
Age mean (SD)	53.37 (16.26)	55.55 (17.02)	−1.378	0.19
Sex male n (%)	116 (46.96)	131 (53.03)	1.028	0.13
FFP transferred, n (%)	89 (44.7)	169 (84.5)	67.337	<0.001*
Platelets transferred, n (%)	183 (92.0)	71 (35.5)	135.017	<0.001*
Both FFP and platelets transferred, n (%)	73 (36.7)	40 (20.0)	12.867	<0.001*
FFP transferred in units (mean±SD/median (IQR))	1.39±2.06/0 (0–2)	4.15±4.46/3 (2-6)	9670.0	<0.001†
Platelet transferred in units (mean±SD/median (IQR))	4.81±3.75/4 (3-6)	1.98±6.91/0 (0–4)	40 285.0	<0.001†

^*χ2 test.

^†Mann-Whitney U test.

FFP, fresh frozen plasma.

Discussion

This study found no significant association between ABO blood group and the requirement for platelet or FFP transfusions among patients with dengue, despite blood group O being the most common among transfused individuals. Patients with dengue requiring transfusion showed more severe biochemical and haematological abnormalities, including elevated liver enzymes, renal dysfunction and profound thrombocytopenia, compared with non-transfused patients with dengue. These findings highlight that transfusion needs in dengue are driven by disease severity rather than blood group distribution. Previous studies have explored the role of genetic factors, including ABO blood groups, in dengue outcomes.^{22 23} Some have reported associations between specific blood groups and disease severity; for example, Kalayanarooj et al observed a higher risk of severe dengue haemorrhagic fever and secondary infections among individuals with blood group AB,²⁴ while others have suggested a protective effect of certain groups. Similarly, Murugananthan et al found that Sri Lankan patients with blood group AB were 2.5 times more likely to develop severe dengue, whereas blood group O appeared to confer a lower risk.⁶ However, a meta-analysis by Hashan et al contradicted these findings, identifying blood group O as a potential predictor of severe dengue.⁷

In the study catchment area, the ABO blood group distribution among blood donors was reported as O 37.86%, B 29.10%, A 26.27% and AB 6.77%.¹⁶ In comparison, our transfused dengue cohort showed higher proportions of groups O (41.7%) and A (28.1%) and a lower proportion of group B (23.1%), with group O remaining the most frequent. Although group O remained predominant, the relatively higher A and lower B proportions in our cohort likely reflect sampling of hospitalised transfused patients rather than a true biological effect, consistent with our finding of no statistically significant association between ABO type and transfusion requirement. Previous laboratory studies have demonstrated that A. albopictus mosquitoes preferentially land and feed on individuals with this blood group and also the most predominant group in our study population.^{25 26} However, the present study did not identify a significant association between the blood group and transfusion requirement in cases when compared with the control group (table 2). This suggests that the higher prevalence of blood group O among transfused cases reflects its overall population distribution rather than an increased susceptibility to mosquito bites or disease severity. Research indicates that males are generally more susceptible to viral infections and often experience more severe disease manifestations than females.²⁷ Consistent with this trend, our study observed that males constituted the majority of transfused patients. However, no sex-stratified association was identified between blood group and transfusion requirement.

Our study found no significant relationship between blood groups and transfusion volume in patients with dengue, indicating that blood group does not influence transfusion requirements. This aligns with findings from Iqbal et al, who reported no correlation between blood groups and disease severity in patients with dengue.²⁸ Nevertheless, further research with larger cohorts is necessary to validate these findings across diverse clinical settings.

Additionally, the results showed that platelet transfusion, either alone or in combination with FFP, was the preferred intervention in dengue cases compared with controls. The mean transfusion volume of FFP was significantly lower, while platelet transfusion was significantly higher in dengue-positive cases than in the control group. This suggests a preference for platelet transfusion over FFP in managing thrombocytopenia and associated complications in patients with dengue.

The present study adds novel evidence by being the first from India to specifically investigate the association between ABO blood group and blood component transfusion requirements in patients with dengue over a prolonged period (2015–2023). Unlike earlier studies that primarily examined ABO groups in relation to disease susceptibility or severity, our study focuses on transfusion needs—a key aspect of clinical management in dengue. The inclusion of a transfused non-dengue comparison group further strengthens the findings by differentiating transfusion patterns due to dengue pathophysiology from those driven by other clinical conditions. These insights can inform blood bank preparedness and allocation strategies during dengue outbreaks, particularly in resource-limited settings where efficient use of blood products is essential.

However, the limitation of this study is the lack of data on cryoprecipitate infusion, preventing a comprehensive assessment of its role in dengue management. Dengue serology was not performed in the non-dengue transfused group, limiting the accuracy of comparisons with transfused dengue cases. Although a substantial number of dengue cases without transfusion were included, blood group data for this subgroup were insufficient. Currently, there is limited data on the association between ABO blood groups and FFP/platelet transfusion needs in dengue cases, highlighting the need for further research across diverse populations to optimise blood component allocation during outbreaks.

Conclusion

In this single-centre retrospective study, no significant association was identified between ABO blood groups and the requirement or volume of platelet or FFP transfusions in patients with dengue. The predominance of group O among transfused cases likely reflects its distribution in the general population rather than increased susceptibility. Although platelet transfusion was more frequent in patients with dengue than in non-dengue transfused controls, these findings should be interpreted with caution due to the absence of cryoprecipitate data, lack of dengue serology in the non-dengue transfused group, and limited blood group information in non-transfused dengue cases. Larger, multicentre studies are warranted to confirm these observations and support blood bank preparedness.

Data availability statement

Data are available upon reasonable request.