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Meta-Analysis
. 2023 May 3;13(1):7164.
doi: 10.1038/s41598-023-34170-3.

Association between ovalocytosis and Plasmodium infection: a systematic review and meta-analysis

Kwuntida Uthaisar Kotepui  1 , Aongart Mahittikorn  2 , Frederick Ramirez Masangkay  3 , Manas Kotepui  4
Affiliations
Meta-Analysis

Association between ovalocytosis and Plasmodium infection: a systematic review and meta-analysis

Kwuntida Uthaisar Kotepui et al. Sci Rep. .

Abstract

Reports of an association between ovalocytosis and protection against Plasmodium infection are inconsistent. Therefore, we aimed to synthesise the overall evidence of the association between ovalocytosis and malaria infection using a meta-analysis approach. The systematic review protocol was registered with PROSPERO (CRD42023393778). A systematic literature search of the MEDLINE, Embase, Scopus, PubMed, Ovid, and ProQuest databases, from inception to 30 December 2022, was performed to retrieve studies documenting the association between ovalocytosis and Plasmodium infection. The quality of the included studies was assessed using the Newcastle-Ottawa Scale. Data synthesis included a narrative synthesis and a meta-analysis to calculate the pooled effect estimate (log odds ratios [ORs]) and 95% confidence intervals (CIs) using the random-effects model. Our database search retrieved 905 articles, 16 of which were included for data synthesis. Qualitative synthesis revealed that over half of the studies showed no association between ovalocytosis and malaria infections or severity. Furthermore, our meta-analysis demonstrated no association between ovalocytosis and Plasmodium infection (P = 0.81, log OR = 0.06, 95% CI - 0.44 to 0.19, I2: 86.20%; 11 studies). In conclusion, the meta-analysis results demonstrated no association between ovalocytosis and Plasmodium infection. Hence, the role of ovalocytosis in relation to protection against Plasmodium infection or disease severity should be further investigated in larger prospective studies.

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Conflict of interest statement

The authors declare no competing interests.

Figures

Figure 1
Figure 1
Study flow diagram.
Figure 2
Figure 2
Forest plot showing the pooled log odds ratio (OR) of the association between Southeast Asian ovalocytosis (SAO) and malaria infection. Abbreviations: Malaria (O) malaria infection in SAO RBCs; Malaria (non-O) malaria infection in non-SAO RBCs; CI confidence interval; blue square effect estimate (log OR); crimson diamond pooled log OR in each subgroup; green diamond pooled log OR in all included studies.
Figure 3
Figure 3
Forest plot showing the pooled log odds ratio (OR) of the association between Southeast Asian ovalocytosis (SAO) and P. vivax infection. Abbreviations: P. vivax (O), P. vivax infection in SAO RBCs; P. vivax (non-O), P. vivax infection in non-SAO RBCs; CI confidence interval; blue square effect estimate (log OR); green diamond, pooled log OR in all included studies.
Figure 4
Figure 4
Leave-one-out sensitivity analysis to identify outliers in the meta-analysis of the log odds ratio between Southeast Asian ovalocytosis and malaria infection. Abbreviations: CI confidence interval; green dot effect estimate.
Figure 5
Figure 5
Sensitivity analysis using the fixed-effects model for the pooled log odds ratio between Southeast Asian ovalocytosis and malaria infection. Abbreviations: CI confidence interval; blue square effect estimate (log OR); crimson diamond pooled log OR in each subgroup; green diamond pooled log OR in all included studies.
Figure 6
Figure 6
Funnel plot demonstrating the asymmetrical distribution of the log odds ratio of individual studies.
See this image and copyright information in PMC

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