Severe Hemolysis during Primaquine Radical Cure of Plasmodium vivax Malaria: Two Systematic Reviews and Individual Patient Data Descriptive Analyses

ABSTRACT. Primaquine (PQ) kills Plasmodium vivax hypnozoites but can cause severe hemolysis in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency. We conducted two systematic reviews. The first used data from clinical trials to determine the variety of definitions and frequency of hematological serious adverse events (SAEs) related to PQ treatment of vivax malaria. The second used data from prospective studies and case reports to describe the clinical presentation, management, and outcome of severe PQ-associated hemolysis necessitating hospitalization. In the first review, SAEs were reported in 70 of 249 clinical trials. There were 34 hematological SAEs among 9,824 patients with P. vivax malaria treated with PQ, nine of which necessitated hospitalization or blood transfusion. Criteria used to define SAEs were diverse. In the second review, 21 of 8,487 articles screened reported 163 patients hospitalized after PQ radical cure; 79.9% of whom (123 of 154) were prescribed PQ at ≥ 0.5 mg/kg/day. Overall, 101 patients were categorized as having probable or possible severe PQ-associated hemolysis, 96.8% of whom were G6PD deficient (< 30% activity). The first symptoms of hemolysis were reported primarily on day 2 or 3 (45.5%), and all patients were hospitalized within 7 days of PQ commencement. A total of 57.9% of patients (77 of 133) had blood transfusion. Seven patients (6.9%) with probable or possible hemolysis died. Even when G6PD testing is available, enhanced monitoring for hemolysis is warranted after PQ treatment. Clinical review within the first 5 days of treatment may facilitate early detection and management of hemolysis. More robust definitions of severe PQ-associated hemolysis are required.


SUPPLEMENTAL APPENDIX S1
Yilma et al: Severe hemolysis during primaquine radical cure of Plasmodium vivax malaria: two systematic reviews and individual patient data descriptive analyses  Objectives Provide an explicit statement of questions being addressed with reference to participants, interventions, comparisons, outcomes, and study design (PICOS).

Protocol and registration
Indicate if a review protocol exists, if and where it can be accessed (e.g., Web address), and, if available, provide registration information including registration number.

6-7
Eligibility criteria Specify study characteristics (e.g., PICOS, length of follow-up) and report characteristics (e.g., years considered, language, publication status) used as criteria for eligibility, giving rationale.

6-7
Information sources Describe all information sources (e.g., databases with dates of coverage, contact with study authors to identify additional studies) in the search and date last searched.

Appendix pp5-6
Search Present full electronic search strategy for at least one database, including any limits used, such that it could be repeated.

Appendix pp5-6
Study selection State the process for selecting studies (i.e., screening, eligibility, included in systematic review, and, if applicable, included in the meta-analysis).

Appendix pp5-6
Data collection process Describe method of data extraction from reports (e.g., piloted forms, independently, in duplicate) and any processes for obtaining and confirming data from investigators.

Data items
List and define all variables for which data were sought (e.g., PICOS, funding sources) and any assumptions and simplifications made.

Risk of bias in individual studies
Describe methods used for assessing risk of bias of individual studies (including specification of whether this was done at the study or outcome level), and how this information is to be used in any data synthesis.

Summary measures
State the principal summary measures (e.g., risk ratio, difference in means).8

Synthesis of results
Describe the methods of handling data and combining results of studies, if done, including measures of consistency (e.g., I 2 ) for each meta-analysis.

7-8
Page 1 of 2 Section/topic # Checklist item Reported on page # Risk of bias across studies Specify any assessment of risk of bias that may affect the cumulative evidence (e.g., publication bias, selective reporting within studies).

8,9, data file
Additional analyses Describe methods of additional analyses (e.g., sensitivity or subgroup analyses, meta-regression), if done, indicating which were pre-specified.

Study selection
Give numbers of studies screened, assessed for eligibility, and included in the review, with reasons for exclusions at each stage, ideally with a flow diagram.9,10,12, Fig 1

Study characteristics
For each study, present characteristics for which data were extracted (e.g., study size, PICOS, follow-up period) and provide the citations.

Data File
Risk of bias within studies Present data on risk of bias of each study and, if available, any outcome level assessment (see item 12).Data file

Results of individual studies
For all outcomes considered (benefits or harms), present, for each study: (a) simple summary data for each intervention group (b) effect estimates and confidence intervals, ideally with a forest plot.

Synthesis of results
Present results of each meta-analysis done, including confidence intervals and measures of consistency.To be eligible for inclusion in the current review, trials had to have been done since 1990, (after which adverse event detection and reporting was more standardised, include one or more treatment arm(s) in which patients were treated with either partial or fully supervised primaquine therapy, daily dosing for at least 5 days' duration.Primaquine administration had to commence within the first 7 days after starting blood schizontocidal therapy.Data from non-primaquine-containing arms in these studies were also extracted for comparative purposes, but restricted to patients treated with chloroquine, dihydroartemisinin-piperaquine or artemether-lumefantrine.Studies meeting the above criteria, but not reporting the presence or absence of adverse effects of treatment, were excluded.
The year of the study was taken as the year in which the paper was published, although the start and end date of patient enrolment were also recorded.

Figure S1 -
Figure S1 -Total dose of PQ (mg/kg) administered (A) before first symptoms of hemolysis and (B) manifestation of severe hemolysis

Table of Contents
Table of Contents .

Table 1 ,
Funding27 Describe sources of funding for the systematic review and other support (e.g., supply of data); role of funders for the systematic review.Box S1 -Search strategy for Review 1 of P. vivax Antimalarial Clinical TrialsSearch strategyAll prospective P. vivax antimalarial clinical trials with a minimum of 28 days follow up, published between Jan 1, 1960 and Aug 23, 2021 were identified by the application of the key terms (listed below) through Medline (Pubmed), Web of Science, Embase and the Cochrane Central Database.Abstracts of all references containing any mention of antimalarial drugs were manually checked to confirm prospective clinical trials, with review of full text when needed.
2,3 Risk of bias across studies Present results of any assessment of risk of bias across studies (see Item 15).9,10, data file Additional analysis Give results of additional analyses, if done (e.g., sensitivity or subgroup analyses, meta-regression [see Item 16]).NADISCUSSIONSummary of evidence Summarize the main findings including the strength of evidence for each main outcome; consider their relevance to key groups (e.g., healthcare providers, users, and policy makers).17-21LimitationsDiscuss limitations at study and outcome level (e.g., risk of bias), and at review-level (e.g., incomplete retrieval of identified research, reporting bias).20 Conclusions Provide a general interpretation of the results in the context of other evidence, and implications for future research.20 FUNDING From: Moher D, Liberati A, Tetzlaff J, Altman DG, The PRISMA Group (2009).Preferred Reporting Items for Systematic Reviews and Meta-Analyses: The PRISMA Statement.
The review process was undertaken by two independent investigators who also performed data extraction(RJC and RNP), and is documented in more detail in Commons et al, Int J Parasitol Drug Drug Res 2017.allopurinolOR amodiaquine OR atovaquone OR artemisinin OR arteether OR artesunate OR artemether OR artemotil OR atovaquone OR azithromycin OR artekin OR chloroquine OR chlorproguanil OR cycloguanil OR clindamycin OR coartem OR dapsone OR dihydroartemisinin OR duo-cotecxin OR doxycycline OR halofantrine OR lumefantrine OR lariam OR malarone OR mefloquine OR naphthoquine OR naphthoquinone OR pafuramidine OR piperaquine OR primaquine OR proguanil OR pyrimethamine OR pyronaridine OR proguanil OR quinidine OR quinine OR riamet OR sulphadoxine OR sulfamethoxazole OR tetracycline OR tafenoquine).All articles reporting at least one case of severe primaquine-associated hemolysis published between 1 January 1940 and 20 May 2020, were identified by the application of the key terms (listed below), through PubMed, Web of Science, Embase and the Cochrane Central Database.Title and abstracts of all references were manually checked to confirm papers that reported data attributable to individual patients receiving primaquine for P. vivax radical cure or terminal prophylaxis.The review process was undertaken by six independent reviewers (DY, EG, KT, RJC, NMD, RNP), with discrepancies resolved by discussion.
The review was registered at PROSPERO[CRD42020196604].Key terms:Literature search (conducted May 2020) with the following key terms (version undertaken in Pubmed): vivax and (hospital* or renal or dialysis or transfusion or severe or serious or haemolysis or hemolysis or fatal or death or died or methemoglobin* or methaemoglobin* Or 'cerebral complicat*' or convuls* or unconscious* or prostrat* or 'kidney injury' or 'renal failure' or 'renal impairment' or haemoglobinuria or hemoglobinuria or 'circulatory collapse' or shock or jaundice or hyperbilirubinemia or hyperbilirubinaemia or 'hepatic dysfunction' or 'liver dysfunction' or bleeding or hemorrhage or haemorrhage or thrombocytopenia or thrombocytopaenia or 'disseminated intravascular coagulation' or DIC or 'acute respiratory distress syndrome' or ARDS or 'pulmonary edema' or 'pulmonary oedema' or 'metabolic acidosis' or hyperlactat* or 'severe anaemia' or 'severe anemia' or hypoglycemia or hypoglycaemia or complicat*)