Child, Preschool ; Humans ; Leukocyte-Adhesion Deficiency Syndrome ; diagnosis ; therapy ; Male

BACKGROUNDLeukocyte adhesion deficiency type 1 (LAD-1) is a rare, autosomal recessive inherited immunodeficiency disease characterized by recurrent severe bacterial infection, impaired pus formation, poor wound healing, associated with the mutation in the CD18 gene responsible for the ability of the leucocytes to migrate from the blood stream towards the site of inflammation. Correct and early diagnosis of LAD-1 is vital to the success of treatment and prevention of aggressive infections. The purpose of this study was to collect the clinical findings of the disease and to identify the genetic entity.

METHODSCD18 expression in the peripheral blood leukocytes from the patient, his parents and normal control was measured with flow cytometry. The entire coding regions of the CD18 gene were screened with direct sequencing genomic DNA.

RESULTSCD18 expression level on this patient's leukocyte surface was significantly decreased, with normal level in control group, his father and mother. Gene analysis revealed that this patient had a homozygous c.899A > T missense mutation in exon 8 of CD18 gene, causing the substitution of Asp to Val at the 300 amino acid. His parents were both heterozygous carriers while no such mutation was found in 50 normal controls.

CONCLUSIONThis study disclosed a novel point mutation Asp 300 Val located in a highly conserved region (HCR) of CD18 and confirmed the heterogeneity of the mutations causing LAD-1, indicating it was quite beneficial to establish correct and early diagnosis in children with severe LAD-1.

Asian Continental Ancestry Group ; CD18 Antigens ; genetics ; Child, Preschool ; DNA Mutational Analysis ; Flow Cytometry ; Humans ; Leukocyte-Adhesion Deficiency Syndrome ; etiology ; genetics ; Male ; Point Mutation ; genetics ; Polymerase Chain Reaction

Chronic/cyclic neutropenia, leukocyte adhesion deficiency syndrome, Papillon-Lefèvre syndrome, and Chédiak-Higashi syndrome are associated with severe periodontitis, suggesting the importance of neutrophils in the maintenance of periodontal health. Various Toll-like receptor (TLR) ligands are known to stimulate neutrophil function, including FcR-mediated phagocytosis. In the present study, the effect of TLR2 activation on the non-opsonic phagocytosis of oral bacteria and concomitant production of reactive oxygen species (ROS) by human neutrophils was evaluated. Neutrophils isolated from peripheral blood were incubated with Streptococcus sanguinis or Porphyromonas gingivalis in the presence of various concentrations of Pam3CSK4, a synthetic TLR2 ligand, and analyzed for phagocytosis and ROS production by flow cytometry and chemiluminescence, respectively. Pam3CSK4 significantly increased the phagocytosis of both bacterial species in a dose-dependent manner. However, the enhancing effect was greater for S. sanguinis than for P. gingivalis. Pam3CSK4 alone induced ROS production in neutrophils and also increased concomitant ROS production induced by bacteria. Interestingly, incubation with P. gingivalis and Pam3CSK4 decreased the amounts of ROS, as compared to Pam3CSK4 alone, indicating the possibility that P. gingivalis survives within neutrophils. However, neutrophils efficiently killed phagocytosed bacteria of both species despite the absence of Pam3CSK4. Although P. gingivalis is poorly phagocytosed even by the TLR2-activated neutrophils, TLR2 activation of neutrophils may help to reduce the colonization of P. gingivalis by efficiently eliminating S. sanguinis , an early colonizer, in subgingival biofilm.
Bacteria* ; Biofilms ; Colon ; Flow Cytometry ; Humans* ; Leukocyte-Adhesion Deficiency Syndrome ; Ligands ; Luminescence ; Neutropenia ; Neutrophils* ; Periodontitis ; Phagocytosis* ; Porphyromonas gingivalis ; Reactive Oxygen Species* ; Streptococcus ; Toll-Like Receptor 2* ; Toll-Like Receptors*

OBJECTIVELeukocyte adhesion deficiency type 1 (LAD-I) is rare. We present 1 case of LAD-I patient diagnosed by gene analysis. His clinical manifestations and genetic mutation features are analyzed in this article.

METHODThe clinical material of the LAD-I patient who was diagnosed by gene analysis was retrospectively analyzed.

RESULTThe patient was a 2-month-old boy. He had a complaint of recurrent fever and cough for 30 days. Pulmonary CT indicated a small to moderate quantity pleural effusion on the right side. His peripheral blood leukocyte and C-reactive protein (CRP) was always significantly higher than normal. After hospitalization he had diarrheal diseases, routine stool test showed 2 RBC cells/high power (HP), WBC 30 cells/HP, stool cultures were negative, digestive tract ultrasonography showed an array of defects, in the sigmoid colon and rectal mucosa suggestive of ulcerative colitis. He was treated with cefoperazone and sulbactam and vancomycin. He had a history of impetigo in his neonatal period and without delayed umbilical cord exfoliation. His family history was normal. ITGB2 genetic mutation analysis revealed a homozygous mutation (1062A > T). His parents did not participate in this study. He had no fever but had diarrheal disease after 1 month of follow up.

CONCLUSIONThis patient had suffered from impetigo, pleural effusion, diarrheal diseases, markedly increased peripheral white blood cell and ITGB2 genetic mutation analysis showed that homozygous mutation (1062A > T). He received a diagnosis of LAD-I.

Asian Continental Ancestry Group ; Colitis, Ulcerative ; diagnosis ; etiology ; Cytoskeletal Proteins ; genetics ; DNA Mutational Analysis ; Flow Cytometry ; Homozygote ; Humans ; Infant ; Leukocyte Count ; Leukocyte-Adhesion Deficiency Syndrome ; complications ; diagnosis ; genetics ; Male ; Muscle Proteins ; genetics ; Pleural Effusion ; diagnosis ; etiology ; Point Mutation ; genetics ; Polymerase Chain Reaction ; Retrospective Studies