Background: Iron deficiency anemia (IDA) and the β-thalassemia trait (BTT) are two main causes of hypochromic–microcytic anemia worldwide. Researchers have described many red blood cell (RBC) indices as screening tests for presumptive differentiation, based on differences observed in complete blood count (CBC) data for each condition. There are few BTT reports in Chile, and neither laboratories nor clinical staff have widely used these indices. Objective: The objective of this study was to evaluate the diagnostic performance of 29 RBC indices in 182 patients (51 BTT and 131 IDA) and compare CBC results in both groups. Methods: A retrospective search was carried out in the Laboratory Information System between January 2021 and February 2024 to collect results from CBC, and 29 RBC indices were calculated for each patient. Then, sensitivity, specificity, positive predictive value, negative predictive value, Youden’s index, positive likelihood ratio, negative likelihood ratio, and diagnostic accuracy were calculated using MedCalc©. Results: The Green and King, Wongprachum, and Keikhaei indices showed the best discriminatory power with Youden index values of 0.923, 0.908, and 0.896, respectively, and significant differences were observed in all CBC parameters between BTT and IDA patients (p < 0.001). Conclusions: The Green and King, Wongprachum, and Keikhaei indices showed the best performance; therefore, they can be used as screening for the differential diagnosis between BTT and IDA in order to improve diagnosis given the important therapeutic and epidemiological implications. In this way, clinical laboratories could have a main role in the investigation of these patients.

Background/Objectives: Thalassemia comprises a group of heterogeneous hereditary hemoglobinopathies characterized by impaired hemoglobin synthesis due to mutations in the α, β, and/or δ globin genes. The resulting ineffective erythropoiesis produces anemia of variable severity depending on the affected globin chain. Although β-thalassemia is most prevalent in the Mediterranean region, the Middle East, and Southeast Asia, migration has contributed to its global spread, including in non-endemic areas. In Chile, published data on β-thalassemia trait (BTT) and β-thalassemia major (BTM) remain scarce. This study aimed to estimate the frequency of BTT in referred outpatients to a clinical laboratory in southern Chile. Methods: A retrospective observational study was conducted between January 2021 and November 2024 at a clinical laboratory in Puerto Montt. Complete Blood Cell counts (CBCs) from unique patients were reviewed, and those confirmed with confirmed thalassemia (HbA2 > 3.5%) were selected. Results: During the study period, 24,634 CBCs were reviewed. Sixty patients were confirmed as carriers of BTT, corresponding to a frequency of 0.24% (CI 95%: 0.18–0.31%) in the referred outpatients to laboratory (60/24,634). This occurrence is higher than the only previously published Chilean estimate but lower than frequencies reported in several South American countries. Conclusions: This investigation demonstrates a relatively low but non-negligible frequency of BTT in outpatients from southern Chile. The findings emphasize the importance of considering BTT in the differential diagnosis of microcytic anemia, a condition often underestimated in routine practice. Broader multicenter studies across Chile are warranted to validate these results and to provide a clearer picture of the epidemiology of β-thalassemia in the country.

Background: Ethylenediaminetetraacetic acid-dependent pseudo thrombocytopenia (EDTA-PCTP) is defined as a false in vitro decrease in the platelet count performed in the EDTA tube due to the spontaneous formation of platelet aggregates that prevent a correct count in hematological auto analyzers. The frequency of EDTA-PCTP varies depending on the population studied, ranging from 0.01% to 30.0%. In Chile, although the diagnosis of this condition is performed in clinical laboratories, only a few isolated reports have been described. Objectives: To determine the prevalence of EDTA-PCTP in a cohort of patients who attended an outpatient clinical laboratory in southern Chile over a period of almost 4 years. Methods: A retrospective analysis was conducted using the Laboratory Information System from January 2021 to November 2024 to identify patients with suspected and confirmed cases of EDTA-PCTP. Results: The prevalence rate observed was 0.044% (12 out of 27,480). Additionally, we established that platelet count measurement from the citrate tube at 2–5 h post-sampling was comparable to the platelet count from the EDTA/K2 tube at time 0 (p > 0.05) in these patients. Conclusions: We conclude that a relatively low prevalence of EDTA-PTCP was identified in a population of patients attending an outpatient laboratory in Chile, marking the first report of its kind in our country. Future studies may validate our findings to enhance understanding of EDTA-PTCP, thereby preventing incorrect diagnoses and treatments.