Clinical Characteristics and Treatment Outcomes of Pediatric Patients with Non-Hodgkin Lymphoma in East Asia

Hemoglobinopathies, merozoite surface protein-2 gene polymorphisms, and acquisition of Epstein Barr virus among infants in Western Kenya

BACKGROUND

Epstein Barr virus (EBV)-associated endemic Burkitt's Lymphoma pediatric cancer is associated with morbidity and mortality among children resident in holoendemic Plasmodium falciparum regions in western Kenya. P. falciparum exerts strong selection pressure on sickle cell trait (SCT), alpha thalassemia (-α^3.7/αα), glucose-6-phosphate dehydrogenase (G6PD), and merozoite surface protein 2 (MSP-2) variants (FC27, 3D7) that confer reduced malarial disease severity. The current study tested the hypothesis that SCT, (-α^3.7/αα), G6PD mutation and (MSP-2) variants (FC27, 3D7) are associated with an early age of EBV acquisition.

METHODS

Data on infant EBV infection status (< 6 and ≥ 6-12 months of age) was abstracted from a previous longitudinal study. Archived infant DNA (n = 81) and mothers DNA (n = 70) samples were used for genotyping hemoglobinopathies and MSP-2. The presence of MSP-2 genotypes in maternal DNA samples was used to indicate infant in-utero malarial exposure. Genetic variants were determined by TaqMan assays or standard PCR. Group differences were determined by Chi-square or Fisher's analysis. Bivariate regression modeling was used to determine the relationship between the carriage of genetic variants and EBV acquisition.

RESULTS

EBV acquisition for infants < 6 months was not associated with -α^3.7/αα (OR = 1.824, P = 0.354), SCT (OR = 0.897, P = 0.881), or G6PD [Viangchan (871G > A)/Chinese (1024 C > T) (OR = 2.614, P = 0.212)] and [Union (1360 C > T)/Kaiping (1388G > A) (OR = 0.321, P = 0.295)]. There was no relationship between EBV acquisition and in-utero exposure to either FC27 (OR = 0.922, P = 0.914) or 3D7 (OR = 0.933, P = 0.921). In addition, EBV acquisition in infants ≥ 6-12 months also showed no association with -α^3.7/αα (OR = 0.681, P = 0.442), SCT (OR = 0.513, P = 0.305), G6PD [(Viangchan (871G > A)/Chinese (1024 C > T) (OR = 0.640, P = 0.677)], [Mahidol (487G > A)/Coimbra (592 C > T) (OR = 0.948, P = 0.940)], [(Union (1360 C > T)/Kaiping (1388G > A) (OR = 1.221, P = 0.768)], African A (OR = 0.278, P = 0.257)], or in utero exposure to either FC27 (OR = 0.780, P = 0.662) or 3D7 (OR = 0.549, P = 0.241).

CONCLUSION

Although hemoglobinopathies (-α^3.7/αα, SCT, and G6PD mutations) and in-utero exposure to MSP-2 were not associated with EBV acquisition in infants 0-12 months, novel G6PD variants were discovered in the population from western Kenya. To establish that the known and novel hemoglobinopathies, and in utero MSP-2 exposure do not confer susceptibility to EBV, future studies with larger sample sizes from multiple sites adopting genome-wide analysis are required.

iTRAQ-Based Proteomic Analysis Reveals Potential Serum Biomarkers for Pediatric Non-Hodgkin's Lymphoma

Non-Hodgkin’s lymphoma (NHL) is the third most common malignant tumor among children. However, at initial NHL diagnosis, most cases are at an advanced stage because of nonspecific clinical manifestations and currently limited diagnostic methods. This study aimed to screen and verify potential serum biomarkers of pediatric NHL using isobaric tags for relative and absolute quantification (iTRAQ)-based proteomic analysis. Serum protein expression profiles from children with B-NHL (n=20) and T-NHL (n=20) and healthy controls (n=20) were detected by utilizing iTRAQ in combination with two-dimensional liquid chromatography-tandem mass spectrometry (2D LC–MS/MS) and analyzed by applying Ingenuity Pathway Analysis (IPA). The candidate biomarkers S100A8 and LRG1 were further validated by using enzyme-linked immunosorbent assays (ELISAs). Receiver operating characteristic (ROC) analysis based on ELISA data was used to evaluate diagnostic efficacy. In total, 534 proteins were identified twice using iTRAQ combined with 2D LC–MS/MS. Further analysis identified 79 and 73 differentially expressed proteins in B-NHL and T-NHL serum, respectively, compared with control serum according to our defined criteria; 34 proteins were overexpressed and 45 proteins underexpressed in B-NHL, whereas 45 proteins were overexpressed and 28 proteins underexpressed in T-NHL (p < 0.05). IPA demonstrated a variety of signaling pathways, including acute phase response signaling and liver X receptor/retinoid X receptor (LXR/RXR) activation, to be strongly associated with pediatric NHL. S100A8 and LRG1 were elevated in NHL patients compared to normal controls according to ELISA (p < 0.05), which was consistent with iTRAQ results. The areas under the ROC curves of S100A8, LRG1, and the combination of S100A8 and LRG1 were 0.873, 0.898 and 0.970, respectively. Our findings indicate that analysis of the serum proteome using iTRAQ combined with 2D LC–MS/MS is a feasible approach for biomarker discovery. Serum S100A8 and LRG1 are promising candidate biomarkers for pediatric NHL, and these differential proteins illustrate a novel pathogenesis and may be clinically helpful for NHL diagnosis in the future.