title: Gene expression analysis of children with acute hematogenous osteomyelitis caused by Methicillin-resistant Staphylococcus aureus: correlation with clinical severity of illness.
abstract: Children with acute hematogenous osteomyelitis (AHO) demonstrate a broad spectrum of clinical manifestations, ranging from mild to severe. Several advances have been achieved in the study of host immune response to acute invasive Staphylococcus aureus infections through gene expression analysis. However, previous research has neither attempted to evaluate the response of children with AHO specific to Methicillin-resistant Staphylococcus aureus (MRSA) nor to correlate gene expression with clinical phenotype. Study objective was to correlate gene expression of children with AHO due to MRSA with clinical severity of illness. Whole blood samples were obtained in Tempus tubes from 12 children with osteomyelitis once cultures obtained directly from the site of infection confirmed to be positive for MRSA. Using an Illumina platform and a systems-wide modular analysis, microarray findings from ten of these children were compared to that of nine healthy (age, ethnicity and gender) matched controls and correlated with clinical severity of illness. Children with AHO from MRSA demonstrated over-expression of innate immunity with respect to neutrophil activity, coagulation, inflammatory response, and erythrocyte development. Concurrently, these children demonstrated under-expression of adaptive immunity with respect to lymphocyte activation and activity of T-cell, cytotoxic or NK cell, and B-cell lines. Three over-expressed genes, P2RX1, SORT1, and RETN, and two under-expressed genes, LOC641788 and STAT 4, were significantly correlated with severity of illness. STAT 4 showed the strongest correlation (R2 = -0.83). STAT4 downregulation could potentially explain under-expression of genes related to adaptive immunity in this cohort of patients with AHO. This study identified specific genes which correspond to disease severity during the early hospitalization of children with AHO from MRSA. Pattern recognition of this combination of genes could help to identify in the future severe clinical phenotypes before the disease is fully manifest and direct appropriate attention and resources to those children.
authors: Department of Pediatrics Infectious Disease, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America; Children's Medical Center, Dallas, Texas, United States of America.
authors: Claudia
authors: C
authors: Gaviria-Agudelo
authors: University of Texas Southwestern Medical Center, Dallas, Texas, United States of America.
authors: Kristen
authors: K
authors: Carter
authors: Children's Medical Center, Dallas, Texas, United States of America.
authors: Naureen
authors: N
authors: Tareen
authors: Baylor Institute for Immunology Research, Dallas, Texas, United States of America; Texas Scottish Rite Hospital, Dallas, Texas, United States of America.
authors: Virginia
authors: V
authors: Pascual
authors: Children's Medical Center, Dallas, Texas, United States of America; Orthopaedic Surgery, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America; Texas Scottish Rite Hospital, Dallas, Texas, United States of America.
authors: Lawson A
authors: LA
authors: Copley
mesh_terms: D000208:Acute Disease; D056704:Adaptive Immunity; D033942:Adaptor Proteins, Vesicular Transport / Q000235:genetics / Q000378:metabolism; D000293:Adolescent; D002097:C-Reactive Protein / Q000032:analysis; D002648:Child; D002675:Child, Preschool; D005260:Female; D005786:Gene Expression Regulation / Q000276:immunology*; D006801:Humans; D007113:Immunity, Innate; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000502:physiology*; D009504:Neutrophils / Q000166:cytology / Q000276:immunology; D010019:Osteomyelitis / Q000235:genetics* / Q000276:immunology* / Q000382:microbiology / Q000473:pathology; D011446:Prospective Studies; D058474:Receptors, Purinergic P2X1 / Q000235:genetics / Q000378:metabolism; D052243:Resistin / Q000235:genetics / Q000378:metabolism; D050797:STAT4 Transcription Factor / Q000235:genetics / Q000378:metabolism; D012720:Severity of Illness Index; D059467:Transcriptome; D000099183:Sortilin
chemical_list: D033942:Adaptor Proteins, Vesicular Transport; D002097:C-Reactive Protein; D058474:Receptors, Purinergic P2X1; D052243:Resistin; D050797:STAT4 Transcription Factor; D000099183:Sortilin; C499624:RETN protein, human