Seroprevalence, cost per donation and reduction in blood supply due to positive and indeterminate results for infectious markers in a blood bank in Lima, Peru

Frequency of allogenic blood transfusion in patients with gastrointestinal cancer: a cross-sectional study in Peru

Background

Gastrointestinal cancer demands a high frequency of transfusions, and the high availability of blood products. We aimed to determine the frequency of blood transfusions and the most used blood products according to the type of gastrointestinal cancer.

Methods

A cross-sectional study was conducted in a Peruvian Type I Hemotherapy and Blood Bank Service of a Private Oncological Clinic during 2016–2018. We included patients with gastrointestinal cancer using the International Code of Diseases. The donations were made in compliance with the requirements of the Programa Nacional de Hemoterapía y Banco de Sangre and in accordance with the Standardised Operational Procedure of the clinic.

Results

We analysed 3,022 patients, of which 163 (5.4%) had gastrointestinal cancer (67.1 ± 12 years). The 80 (49.1%) men did not show significant differences with the 83 (50.9%) women (p = 0.178). The most frequent neoplasia was the colon (41.7%) and pancreas (37.4%). Three hundred and four blood products were transfused (average 1.8 ± 2.5 units (range: 1–30 units/patient)), of which 81.3% (247 units) were red blood cells concentrated, 8.6% (26 units) were fresh-frozen-plasma (FFP) and 6.6% (20 units) were cryoprecipitate. The type of cancer that most blood products demanded was colon neoplasia (41.8%), followed by pancreatic cancer (26.3%) and liver cancer (10.9%). We determined that ~55% of patients were O Rh(D)+ and in five patients we were poly-transfused.

Conclusion

Our findings suggested that patients with gastrointestinal cancer require large numbers of transfusions of blood cell concentrate and FFP. Also, we showed that cancer of the colon, pancreas and liver demanded more than 75% of blood products.

Evaluation of the Chagas Western Blot IgG Assay for the Diagnosis of Chagas Disease

Chagas disease is a debilitating and often fatal pathology resulting from infection by the protozoan parasite Trypanosoma cruzi. In its recommendations, the World Health Organization states that the diagnosis of T. cruzi infection is usually based on the detection of antibodies against T. cruzi antigens and performed with two methodologically different assays. An inconclusive result can be resolved with a third “confirmatory” assay. The objective of this article is to evaluate the effectiveness of the Chagas Western Blot IgG assay (LDBio Diagnostics, Lyon, France) as a confirmatory serologic test. The Chagas Western Blot IgG assay was performed with native antigens derived from a T. cruzi strain of the TcVI genotype. Retrospective sera were provided by two parasitology laboratories (France and Argentina). The sensitivity, specificity, positive predictive value and negative predictive value of the Chagas blot were all 100% in our sera collection. The Chagas blot is an easy and qualitative method for the diagnosis of Chagas disease, with results in less than 2 h. This immunoblot has potential as a supplemental test for the confirmation of the presence of antibodies against T. cruzi in serum specimens. Nonetheless, the very good initial results presented here will need to be confirmed in larger studies.

Economic evaluations addressing diagnosis and treatment strategies for neglected tropical diseases: an overview

Neglected tropical diseases (NTDs) are those affecting vulnerable people and causing additional social and economic burden. The aim of this study was to carry out a general overview of the health economic assessments involving the diagnosis and treatment of six NTDs: cutaneous leishmaniasis (CL), Chagas disease, cysticercosis, filariasis, schistosomiasis and visceral leishmaniasis (VL). The literature search was based on two of the main medical literature databases (Medline and SciELO) and identified 46 studies. Twenty-six studies (57%) addressed therapeutic strategies, while other 20 (43%) assessed diagnostic or both diagnostic and therapeutic approaches. The studies were published between 1994 and 2021, and 57% of them (26/46) were carried out in four countries. Cost-effectiveness analyses were conducted in 59% (27/46) of the studies. Economic studies of NTDs have timidly increased in recent years. Despite the improvement of analytical methods, completeness and accuracy of information, there are few new technologies applied to NTDs and public health systems. In addition, economic studies for NTDs are concentrated in a few countries. Thus, this review points out the need for investment in research, development and training of human resources dedicated to the economic analysis in health, especially on NTDs, as a strategy to reduce inequalities by optimizing the use of health resources.

Usefulness of FC-TRIPLEX Chagas/Leish IgG1 as confirmatory assay for non-negative results in blood bank screening of Chagas disease

A relevant issue in Chagas disease serological diagnosis regards the requirement of using several confirmatory methods to elucidate the status of non-negative results from blood bank screening. The development of a single reliable method may potentially contribute to distinguish true and false positive results. Our aim was to evaluate the performance of the multiplexed flow-cytometry anti-T. cruzi/Leishmania IgG1 serology/(FC-TRIPLEX Chagas/Leish IgG1) with three conventional confirmatory criteria (ELISA-EIA, Immunofluorescence assay-IIF and EIA/IIF consensus criterion) to define the final status of samples with actual/previous non-negative results during anti-T. cruzi ELISA-screening in blood banks. Apart from inconclusive results, the FC-TRIPLEX presented a weak agreement index with EIA, while a strong agreement was observed when either IIF or EIA/IIF consensus criteria were applied. Discriminant analysis and Spearman's correlation further corroborates the agreement scores. ROC curve analysis showed that FC-TRIPLEX performance indexes were higher when IIF and EIA/IIF consensus were used as a confirmatory criterion. Logistic regression analysis further demonstrated that the probability of FC-TRIPLEX to yield positive results was higher for inconclusive results from IIF and EIA/IIF consensus. Machine learning tools illustrated the high level of categorical agreement between FC-TRIPLEX versus IIF or EIA/IIF consensus. Together, these findings demonstrated the usefulness of FC-TRIPLEX as a tool to elucidate the status of non-negative results in blood bank screening of Chagas disease.