Clinical characteristics, laboratory findings, and tolerance acquisition in infants with cow's milk protein allergy in a private center in Lima, Peru for the period 2021-2022.

BACKGROUND: Cow's milk protein allergy (CMPA) remains relatively understudied in Latin America. METHODS: In this observational study, we enrolled 64 patients with a median age of 3 months, of whom 60% were male. Patients included had a history of IgE-mediated reactions with IgE sensitization or non-IgE-mediated reactions or symptoms following exposure to cow's milk. They underwent skin prick test, ImmunoCAP, fecal calprotectin (FC), and fecal eosinophil-derived neurotoxin (EDN), in addition to double-blinded placebo-controlled oral food challenges (DBPCFC), with clinical evolution and tolerance acquisition observed over 1 year. RESULTS: Malnutrition was present in 78.1% of patients, and 87.5% had a family history of atopy, with 51.6% receiving exclusive breastfeeding. Gastrointestinal manifestations were prevalent in 90.6% of patients, followed by dermatological manifestations (10.9%), with only 2 experiencing anaphylaxis. IgE-mediated CMPA was observed in only six patients. In those with non-IgE-mediated CMPA, FC had a median of 284 mg/dL (IQR: 138.5-415.5), while EDN had a median of 508.5 mg/dL (IQR: 160.25-868). One year after diagnosis, median FC significantly decreased (p < 0.0001), and malnutrition prevalence reduced to 17.1%. Moreover, 81% of patients acquired tolerance following DBPCFC, with 52% utilizing nutritional replacement formulas at diagnosis. Notably, 94% of those extensively hydrolyzed casein-based formulas achieved tolerance (p = 0.08). CONCLUSION: Our findings provide a foundational framework for future investigations into CMPA diagnosis, tolerance acquisition, and the utilization of hypoallergenic formulas tailored to the unique characteristics of our region.

Humoral Response after a Fourth Dose with mRNA-1273 in Healthcare Workers with and without a History of SARS-CoV-2 Infection and Previously Vaccinated with Two Doses of BBIBP-CorV Plus BNT162b2 Vaccine.

There is limited information on the kinetics of the humoral response elicited by a fourth dose with a heterologous mRNA1273 booster in patients who previously received a third dose with BNT162b2 and two doses of BBIBP-CorV as the primary regimen. We conducted a prospective cohort study to assess the humoral response using Elecsys® anti-SARS-CoV-2 S (anti-S-RBD) of 452 healthcare workers (HCWs) in a private laboratory in Lima, Peru at 21, 120, 210, and 300 days after a third dose with a BNT162b2 heterologous booster in HCW previously immunized with two doses of BBIBP-CorV, depending on whether or not they received a fourth dose with the mRNA1273 heterologous vaccine and on the history of previous SARS infection -CoV-2. Of the 452 HCWs, 204 (45.13%) were previously infected (PI) with SARS-CoV-2, and 215 (47.57%) received a fourth dose with a heterologous mRNA-1273 booster. A total of 100% of HCWs presented positive anti-S-RBD 300 days after the third dose. In HCWs receiving a fourth dose, GMTs 2.3 and 1.6 times higher than controls were observed 30 and 120 days after the fourth dose. No statistically significant differences in anti-S-RBD titers were observed in those HCWs PI and NPI during the follow-up period. We observed that HCWs who received a fourth dose with the mRNA1273 and those previously infected after the third dose with BNT162b2 (during the Omicron wave) presented higher anti-S-RBD titers (5734 and 3428 U/mL, respectively). Further studies are required to determine whether patients infected after the third dose need a fourth dose.

First Report of OXA-181-Producing Enterobacterales Isolates in Latin America.

We characterized five carbapenemase-producing Enterobacterales (CPE) isolates from two health care institutions in Lima, Peru. The isolates were identified as Klebsiella pneumoniae (n = 3), Citrobacter portucalensis (n = 1), and Escherichia coli (n = 1). All were identified as blaOXA-48-like gene carriers using conventional PCR. Whole-genome sequencing found the presence of the blaOXA-181 gene as the only carbapenemase gene in all isolates. Genes associated with resistance to aminoglycosides, quinolones, amphenicols, fosfomycins, macrolides, tetracyclines, sulfonamides, and trimethoprim were also found. The plasmid incompatibility group IncX3 was identified in all genomes in a truncated Tn6361 transposon flanked by ΔIS26 insertion sequences. The qnrS1 gene was also found downstream of blaOXA-181, conferring fluoroquinolone resistance to all isolates. CPE isolates harboring blaOXA-like genes are an increasing public health problem in health care settings worldwide. The IncX3 plasmid is involved in the worldwide dissemination of blaOXA-181, and its presence in these CPE isolates suggests the wide dissemination of blaOXA-181 in Peru. IMPORTANCE Reports of carbapenemase-producing Enterobacterales (CPE) isolates are increasing worldwide. Accurate detection of the ß-lactamase OXA-181 (a variant of OXA-48) is important to initiate therapy and preventive measures in the clinic. OXA-181 has been described in CPE isolates in many countries, often associated with nosocomial outbreaks. However, the circulation of this carbapenemase has yet to be reported in Peru. Here, we report the detection of five multidrug-resistant CPE clinical isolates harboring blaOXA-181 in the IncX3-type plasmid, a potential driver of dissemination in Peru.

Cerebral Cryptococcosis Associated with CD4+ T-lymphocytopenia in Non-HIV Patients after SARS-CoV-2 Infection: Case Series in a Specialized Institute in Lima, Peru.

Cases of cryptococcosis have been reported in patients with COVID-19. The majority are in patients with severe symptoms or who received immunosuppressants. However, there is still no clear association between COVID-19 and cryptococcosis. We report eight cases of cerebral cryptococcosis associated with CD4+ T lymphocytopenia in non-HIV patients after SARS-CoV-2 infection. The median age was 57 years and 5/8 were male. In addition, 2/8 of patients had diabetes, and 8/8 had a history of mild COVID-19, with a median of 75 days before diagnosis of cerebral cryptococcosis. All patients denied having received prior immunosuppressive therapy. The most frequent symptoms were confusion (8/8), headache (7/8), vomiting (6/8), and nausea (6/8) All patients were diagnosed by isolating Cryptococcus in cerebrospinal fluid. The median CD4+ and CD8+ T lymphocytes were 247 and 173.5, respectively. Other causes of immunosuppression, such as HIV or HTLV infection, were excluded in all patients. Finally, three patients died, and one presented long-term visual and auditory sequelae. The CD4+/CD8+ T lymphocyte count normalized during follow-up in those patients who survived. We hypothesize that CD4+ T lymphocytopenia in the patients in this case series could increase the risk of cryptococcosis after SARS-CoV-2 infection.

Neutralizing Antibodies as Predictors of Vaccine Breakthrough Infection in Healthcare Workers Vaccinated with or without a Heterologous Booster Dose: A Cohort Study during the Third COVID-19 Wave in Peru.

We evaluated neutralizing antibody (NAbs) levels as a protective factor against vaccine breakthrough infection (VBI) in healthcare workers (HCWs) during the third COVID-19 wave in Peru. This retrospective cohort study employed the information from a private laboratory in Lima (Peru) of HCW who received only two BBIBP-CorV vaccines or (additionally) a heterologous booster with BNT162b2. We evaluated the association between the VBI and the levels of NAbs at 21, 90, 180, and 210 days after the BBIBP-CorV second dose. NAbs were calculated with the cPass™ SARS-CoV-2 Neutralization Antibody Detection kit (surrogate virus neutralization test (sVNT)) and the Elecsys® anti-SARS-CoV-2 S Test. Of the 435 HCW evaluated, 31.72% had an infection previous to vaccination, 68.28% received a booster dose, and 23.21% had a VBI during the third wave. The variables associated with a lower risk of VBI were male sex (aRR: 0.43) and those who had (180 days after BBIBP-CorV inoculation) NAbs levels ≥ 60% (aRR: 0.58) and ≥90% (aRR: 0.59) on cPass™, and ≥500 with Elecsys® (aRR: 0.58). HCW whose NAbs persisted at higher levels six months after the BBIBP-CorV showed a lower risk of suffering from a VBI during the third COVID-19 wave.

Characteristics and factors associated with mortality in tracheostomized patients with COVID-19: a retrospective cohort study in a hospital in Tacna, Peru. / Características y factores asociados a la mortalidad en pacientes con COVID-19 traqueostomizados: estudio de cohorte retrospectivo en un hospital de Tacna, Perú.

OBJECTIVE: We aimed to describe the main demographic, clinical, laboratory and therapeutic characteristics and to identify whether they are associated with mortality in tracheostomized patients. MATERIAL AND METHODS.: Retrospective cohort study in adult patients diagnosed with COVID-19, admitted to ICU (Intensive Care Unit) and requiring tracheostomy. Demographic, clinical, laboratory and treatment data were obtained from the medical records of patients admitted to Hospital III Daniel Alcides Carrión in Tacna. The Cox proportional hazards model was used for survival analysis and hazard ratios (HR) with their 95% confidence intervals (95%CI) were calculated. RESULTS.: We evaluated 73 patients, 72.6% were men, the most common comorbidities were obesity (68.5%), type 2 diabetes mellitus (35.6%), and arterial hypertension (34.2%). Thirty-seven percent of the participants died during their stay at the ICU. The median time from intubation to tracheostomy and the duration of tracheostomy was 17 (RIC: 15-21) and 21 (RIC: 3-39) days, respectively. Multivariate analysis showed that the factors associated with mortality were procalcitonin > 0.50 ng/dL at the time of tracheostomy (HRa: 2.40 95%CI: 1.03-5.59) and a PaO2/FiO2 ratio less than or equal to 150 mmHg (HRa: 4.44 95%CI: 1.56-12.60). CONCLUSIONS.: The factors associated with mortality at the time of tracheostomy were procalcitonin > 0.50 ng/dL and a PaO2/FiO2 ratio less than or equal to 150 mmHg.

OBJETIVO.: Describir las principales características demográficas, clínicas, laboratoriales y terapéuticas e identificar si están asociados con la mortalidad en pacientes traqueostomizados. MATERIAL Y MÉTODOS.: Estudio de cohorte retrospectiva en pacientes adultos con diagnóstico de COVID-19, ingresados a UCI (Unidad de Cuidados Intensivos) y que requirieron traqueostomía. Se extrajeron datos demográficos, clínicos, laboratoriales y de tratamiento de las historias clínicas de pacientes que ingresaron al Hospital III Daniel Alcides Carrión de Tacna. Para el análisis de supervivencia se empleó el modelo de riesgos proporcionales de Cox y se calcularon los cocientes de riesgo instantáneos (HR) con sus intervalos de confianza al 95% (IC95%). RESULTADOS.: Se evaluaron 73 pacientes, el 72,6% eran hombres, las comorbilidades más comunes fueron obesidad (68,5%), diabetes mellitus tipo 2 (35,6%) e hipertensión arterial (34,2%). El 37% de los participantes fallecieron durante la estancia en UCI. La mediana de tiempo desde la intubación hasta la traqueostomía y la duración de esta fue 17 (RIC: 15−21) y 21 (RIC: 3−39) días, respectivamente. El análisis multivariado mostró que los factores asociados a mortalidad, fueron presentar un valor de procalcitonina > 0,50 ng/dL en el momento de la traqueostomía (HRa: 2,40 IC95%: 1,03−5,59) y el nivel de PaO2/FiO2 menor o igual a 150 mmHg, (HRa: 4,44 IC95%: 1,56−12,60). CONCLUSIONES.: Los factores asociados a mortalidad al momento de realizar la traqueostomía fueron presentar un valor de procalcitonina > 0,50 ng/dL y un cociente PaO2/FiO2 menor o igual a 150 mmHg.

Diagnostic performance of the time to positivity of blood cultures to distinguish true bacteremia from contaminants based on an automated system. / Utilidad diagnóstica de los tiempos de positividad de hemocultivos para distinguir verdaderas bacteriemias de contaminantes en base a un sistema automatizado.

OBJECTIVE.: To determine the diagnostic performance of blood culture positivity times for distinguishing true bacteremia from contaminants in the automated "BACT/ALERT®" system. MATERIALS AND METHODS.: A cross-sectional, diagnostic test-type study was conducted from a database of blood culture samples processed between January 2016 and August 2021. All blood culture samples from patients with suspected bacteremia were included; blood culture samples were entered into the "BACT/ALERT®" system to differentiate true bacteremia from contaminants. RESULTS.: We obtained 33,951 blood cultures samples, of which 3875 were positive. Of the total number of positive blood cultures, 75.2% (n=2913) were true bacteremia and 24.8% (n=962) were contaminants. The median time to positivity in blood cultures with true bacteremia was significantly shorter (16.3 hours; IQR: 11.2 - 24.9) than the median time to positivity of blood cultures with contaminants (22.5 hours; IQR: 18.4 - 31.8; p<0.001). The positivity time showed the capacity to differentiate true bacteremia from contaminants, with an AUC-ROC of 0.73 (95%CI: 0.71 - 0.75), with 85% and 63% sensitivity and specificity respectively for the diagnosis of contaminants when the positivity time exceeds 16.5 hours. The use of antibiotics prior to sampling delayed the time to positivity, while having fever before sampling shortened the time to positivity. CONCLUSIONS.: Our results show good diagnostic performance of blood culture positivity times to differentiate true bacteremia from contaminants using the "BACT/ALERT®" system when the positivity time was longer than 16.5 hours.

OBJETIVO.: Determinar la utilidad diagnóstica de los tiempos de positividad de hemocultivos para distinguir verdaderas bacteriemias de contaminantes en el sistema automatizado «BACT/ALERT®¼. MATERIALES Y MÉTODOS.: Se realizó un estudio transversal de tipo pruebas diagnósticas, a partir de una base de datos de muestras de hemocultivos procesadas entre enero del 2016 y agosto del 2021. Se incluyeron todas las muestras de hemocultivos de pacientes con sospecha de bacteriemia, las muestras de hemocultivos fueron ingresadas al sistema «BACT/ALERT®¼ para diferenciar verdaderas bacteriemias de contaminantes. RESULTADOS.: Se analizó un total de 33 951 frascos de hemocultivos y se obtuvieron 3875 frascos positivos. El 75,2% (n=2913) del total de hemocultivos positivos fueron verdaderas bacteriemias y 24,8% (n=962) fueron contaminantes. La mediana de tiempo de positividad en los hemocultivos con verdaderas bacteriemias fue significativamente menor (16,3 horas; RIC: 11,2 - 24,9) que la mediana de tiempo de positividad de hemocultivos con contaminantes (22,5 horas; RIC: 18,4 - 31,8; p<0,001). El tiempo de positividad demostró capacidad discriminante para diferenciar verdaderas bacteriemias de contaminantes, con un AUC-ROC de 0,73 (IC95%: 0,71 - 0,75), con 85% y 63% de sensibilidad y especificidad respectivamente para el diagnóstico de contaminantes cuando el tiempo de positividad supera las 16,5 horas. La administración de antibióticos previos a la toma retrasó el tiempo de positividad, en cambio, haber presentado fiebre antes de la toma de muestra acortó el tiempo de positividad. CONCLUSIONES.: Nuestros resultados muestran un buen desempeño de los tiempos de positividad de hemocultivos para diferenciar verdaderas bacteriemias de contaminantes utilizando el sistema «BACT/ALERT®¼ cuando el tiempo de positividad fue superior a 16,5 horas.

Determination of PaO2/FiO2 after 24 h of invasive mechanical ventilation and ΔPaO2/FiO2 at 24 h as predictors of survival in patients diagnosed with ARDS due to COVID-19.

Introduction: Acute respiratory distress syndrome (ARDS) due to Coronavirus Disease 2019 (COVID-19) causes high mortality. The objective of this study is to determine whether the arterial pressure of oxygen/inspiratory fraction of oxygen (PaO2/FiO2) 24 h after invasive mechanical ventilation (IMV) and the difference between PaO2/FiO2 at 24 h after IMV and PaO2/FiO2 before admission to IMV (ΔPaO2/FiO2 24 h) are predictors of survival in patients with ARDS due to COVID-19. Methods: A retrospective cohort study was conducted that included patients with ARDS due to COVID-19 in IMV admitted to the intensive care unit (ICU) of a hospital in southern Peru from April 2020 to April 2021. The ROC curves and the Youden index were used to establish the cut-off point for PaO2/FiO2 at 24 h of IMV and ΔPaO2/FiO2 at 24 h associated with mortality. The association with mortality was determined by Cox regression, calculating the crude (cHR) and adjusted (aHR) risk ratios, with their respective 95% confidence intervals (95% CI). Results: Two hundred patients were analyzed. The average age was 54.29 years, 79% were men, and 25.5% (n = 51) died. The cut-off point calculated for PaO2/FiO2 24 h after IMV and ΔPaO2/FiO2 24 h was 222.5 and 109.5, respectively. Those participants with a value below the cut-off point of ΔPaO2/FiO2 24 h and PaO2/FiO2 24 h after IMV had higher mortality, aHR = 3.32 (CI 95% [1.82-6.07]) and aHR = 2.87 (CI 95% [1.48-5.57]) respectively. Conclusion: PaO2/FiO2 24 h after IMV and ΔPaO2/FiO2 24 h in patients diagnosed with ARDS due to COVID-19 on IMV were associated with higher hospital mortality. These findings are helpful to identify those patients with a higher risk of dying on admission to the ICU.

Genetic studies to determine the risk of non-ischemic sudden death: review article / Estudios genéticos para determinar el riesgo de muerte súbita no isquémica: artículo de revisión

Heart disease is the cause of sudden death in more than 80% of cases. Ischemic heart disease is the cause for 90% of all sudden cardiac deaths, while in the remaining 10% of cases, heart diseases have a hereditary origin and comprise a wide spectrum of disorders that include cardiomyopathies and channelopathies. The aim of this review is to highlight the importance of genetic counseling for patients with hereditary cardiovascular disease and its evaluation by a multidisciplinary team.

La cardiopatía es la causa de muerte súbita en más del 80% de casos. La cardiopatía isquémica es responsable en el 90% del total de las muertes súbitas cardiacas, mientras que en el 10% de casos restantes, las cardiopatías tienen un origen hereditario y comprenden un amplio espectro de trastornos que incluyen a las cardiomiopatías y las canalopatías. El objetivo de esta revisión es poner en evidencia la importancia del asesoramiento genético de los pacientes con enfermedad cardiovascular hereditaria y su evaluación a través de un equipo multidisciplinario.

Humoral Immune Response Induced by the BBIBP-CorV Vaccine (Sinopharm) in Healthcare Workers: A Cohort Study.

Insufficient data have been reported about the effect of the inactivated SARS-CoV-2 vaccine (BBIBP-CorV) on the humoral response through time in healthcare workers (HCW). This retrospective cohort studied the information of 252 HCW from a private laboratory, comparing the antibody-mediated response provoked by BBIBP-CorV between HCW previously infected with SARS-CoV-2 (PI) and not previously infected (NPI), employing the Elecsys® anti-SARS-CoV-2 S and the cPass™ SARS-CoV-2 Neutralization Antibody Detection kit at intervals of 21, 90, and 180 days after vaccination. The presence of neutralizing antibodies in HCW 21 days after full vaccination was 100% in PI and 91.60% in NPI. We observed a progressive decrease in antibody levels over time in both groups. Comparing HCW PI with NPI, PI had a 10.9, 14.3, and 8.6-fold higher antibody titer with the Elecsys® anti-SARS-CoV-2 S at 21 (p < 0.001), 90 (p< 0.001) and 180 days (p < 0.001) respectively, compared to NPI. Using the percent of signal inhibition (PSI) of the antibody neutralization cPass™, HCW PI showed a level of 1.3, 2.0, and 3.1 times more antibodies, at 21 (p < 0.001), 90 (p < 0.001), and 180 days (p < 0.001) respectively, compared to NPI. We determined a progressive decrease in humoral immunity over time, particularly higher in those NPI.

Evaluation of the Humoral Immune Response of a Heterologous Vaccination between BBIBP-CorV and BNT162b2 with a Temporal Separation of 7 Months, in Peruvian Healthcare Workers with and without a History of SARS-CoV-2 Infection.

Information on the effects of a heterologous booster in adult patients first vaccinated with the BBIBP-CorV vaccine is limited. This prospective cohort study evaluated the humoral response of 152 healthcare workers (HCWs) from a private laboratory in Lima (Peru) before and after receiving the BNT162b2 vaccine, with a seven-month interval since the BBIBP-CorV doses. We employed the Elecsys® anti-SARS-CoV-2 S and the cPass™ SARS-CoV-2 Neutralization Antibody (NAbs) assays to evaluate anti-S-RBD IgG and NAbs, respectively. Of the 152 HCWs, 79 (51.98%) were previously infected (PI) with SARS-CoV-2 and 73 (48.02%) were not previously infected (NPI). The proportion of HCWs with positive NAbs, seven months after the BBIBP-CorV immunization, was 49.31% in NPI and 92.40% in PI. After the booster, this ratio increased to 100% in both groups. The anti-S-RBD IgG and NAbs in the HCWs' NPI increased by 32.7 and 3.95 times more, respectively. In HCWs' PI, this increment was 5 and 1.42 times more, respectively. There was no statistical association between the history of previous SARS-CoV-2 infection and the titer of anti-S-RBD IgG and NAbs after the booster. The humoral immunity presented a robust increase after receiving the BNT162b2 booster and was more pronounced in NPI.

Correction to: Atypical hyperglycemia presentation suggests considering a diagnostic of other types of diabetes: first reported GCK-MODY in Perú.

[This corrects the article DOI: 10.1186/s40842-019-0091-x.].

Atypical hyperglycemia presentation suggests considering a diagnostic of other types of diabetes: first reported GCK-MODY in Perú.

BACKGROUND: Prevalence of maturity-onset diabetes of the young (MODY) is estimated between 1 and 2% of all diabetes cases. In Latin-America little information has been described about the frequency of the disease, perhaps due to limited access to genetic studies. CASE PRESENTATION: We present the case of a male patient with a history of two years of fatigue, mild hyperglycemia and intermittent polyuria, accompanied by a recent history of weight loss. He was diagnosed initially as type 2 diabetes, but in the follow-up as a patient with type 1 diabetes. He required relatively low doses of insulin and was evaluated in the endocrinology service at a hospital in Lima. The results of glucose, insulin and C-peptide in the oral glucose tolerance test (OGTT) performed were not consistent with a type 1 diabetes. Moreover, the age of the patient and the clinical characteristics did not strongly suggest a diagnosis of type 2 diabetes either. These clinical features had prompted us to carry out the genetic study. The genetic test performed with a genetic MODY panel through a massive sequencing. Heterozygous pathogenic for a variant in GCK gene was found (c.629 T > C, p.Met210Thr.). His parents were negative for this variant after performed the genetic test. CONCLUSIONS: This is the first case of MODY for a pathogenic variant in the GCK gene reported in Perú. The genetic evaluation of a clinical suspicion of MODY is important to confirm the diagnosis and establish an adequate treatment in patients.

Updated Frequency of EGFR and KRAS Mutations in NonSmall-Cell Lung Cancer in Latin America: The Latin-American Consortium for the Investigation of Lung Cancer (CLICaP).

INTRODUCTION: Previously, we reported the frequency of epidermal growth factor receptor (EGFR) and KRAS mutations in nonsmall-cell lung cancer (NSCLC) patients in Latin America. The EGFR mutation frequency was found between Asian (40%) and Caucasian (15%) populations. Here, we report the updated distribution of NSCLC mutations. METHODS: A total of 5738 samples from NSCLC patients from Argentina (1713), Mexico (1417), Colombia (1939), Peru (393), Panama (174), and Costa Rica (102) were genotyped for EGFR and KRAS. RESULTS: The median patient age was 62.2 ± 12.3 years; 53.5% were women, 46.7% had a history of smoking, and 95.2% had adenocarcinoma histology. The frequency of EGFR mutations was 26.0% (95% confidence interval [CI], 24.9-27.1; Argentina, 14.4% [12.8-15.6]; México, 34.3% [31.9-36.7]; Colombia, 24.7% [22.8-26.6]; Peru, 51.1% [46.2-55.9]; Panamá, 27.3 [20.7-33.9]; and Costa Rica, 31.4% [22.4-40.4]). The frequency of KRAS mutations was 14.0% (9.1-18.9). In patients with adenocarcinoma, EGFR mutations were independently associated with gender (30.7% females vs. 18.4% males; p < 0.001), nonsmoker status (27.4% vs. 17.1%, p < 0.001), ethnicity (mestizo/indigenous, 35.3% vs. Caucasian, 13.7%, p < 0.001), and the absence of KRAS mutation (38.1% vs. 4.7%; p < 0.001). The overall response rate to EGFR tyrosine kinase inhibitors was 60.6% (95% CI, 52-69), with a median progression-free survival and overall survival of 15.9 (95% CI, 12.420.6) and 32 months (95% CI, 26.5-37.6), respectively. CONCLUSION: Our findings support the genetic heterogeneity of NSCLC in Latin America, confirming that the frequency of EGFR mutations is intermediate between that observed in the Asian and Caucasian populations.