Incidental diagnosis of leukocyte adhesion deficiency type II following ABO typing.

Individuals with the Bombay phenotype (Oh) in the ABO blood group system do not express the H, A, and B antigens but have no clinical symptoms. Bombay phenotype with clinical symptoms has been described in leukocyte adhesion deficiency type II (LAD II), a fucosylation disorder caused by mutations in SLC35C1. Only few LAD II patients have been described so far. Here we describe an additional patient, a 22-year old male, born to unrelated parents, presenting with inflammatory skin disease, periodontitis, growth, and mental retardation, admitted to the department of dentistry for treatment under general anesthesia. Pre-operative routine investigations revealed the presence of the Bombay phenotype (Oh). Genomic sequencing identified two novel triplet deletions of the SLC35C1 gene. Functional investigations confirmed the diagnosis of LAD II. Therapy with oral fucose led to the disappearance of the chronic skin infections and improvements in behavior and attention span.

Leukocyte adhesion deficiency type III: clinical features and treatment with stem cell transplantation.

Leukocyte adhesion deficiency type III (LADIII) is an autosomal recessive disorder that presents with a severe leukocyte adhesion defect and a Glanzmann-type thrombocytopathy. Hematopoietic stem cell transplantation (HSCT)--the only definitive treatment for LADIII--appears to have a high rate of complications. In this study, we describe a new group of patients with LADIII, highlighting further clinical and immunologic aspects of this disease, and reevaluating the effectiveness of HSCT for its treatment. The patients had clinical and laboratory findings consistent with LADIII. Molecular analysis confirmed the presence of a mutation in the kindlin-3 gene. HSCT was carried out in 3 patients and was successful in 2. The diagnosis of LADIII should be considered in all patients who present with recurrent infections and a bleeding diathesis, regardless of the leukocyte count. LADIII is a primary immune deficiency, which can be successfully corrected by bone marrow transplantation if applied early in the course of the disease using appropriate conditioning.

Leucocyte adhesion deficiency III in a mixed-breed dog.

BACKGROUND: Leucocyte adhesion deficiencies are inherited disorders characterised by immunodeficiency leading to recurrent infections and a marked leucocytosis. We describe the clinical characteristics, diagnosis and management of an Australian mixed- breed dog with leucocyte adhesion deficiency III. CASE REPORT: A 16-month-old male, neutered, German Shepherd × Rottweiler dog was investigated for pyrexia, persistent leucocytosis, marked periodontal disease, lameness, increased mucosal haemorrhages and poor wound healing. Numerous diagnostics were performed including a leucocyte adhesion deficiency III PCR test, which was positive. The patient was managed with topical pressure at bleeding sites, antibiotics, analgesics and dental prophylaxis when required. DISCUSSION: Leucocyte adhesion deficiency III is a rare disorder that manifests because of impaired activation of beta integrins. This results in an absence of neutrophil chemotaxis and adhesion, and platelet dysfunction. Mutations within the KINDLIN3 gene resulting in the absence of the kindlin-3 protein have been identified as the cause of this disease. Leucocyte adhesion deficiency III has previously been reported in humans and a German Shepherd dog. This report describes the first reported case of leucocyte adhesion deficiency III in Australia and the first reported case in a mixed-breed dog worldwide.

A novel flow cytometry-based platelet aggregation assay.

The main function of platelets is to maintain normal hemostasis. Inefficient platelet production and/or defective platelet function results in bleeding disorders resulting from a wide range of genetic traits and acquired pathologies. Several platelet function tests have been developed for use in the clinic and in experimental animal models. In particular, platelet aggregation is routinely measured in an aggregometer, which requires normal platelet counts and significant blood sample volumes. For this reason, the analysis of thrombocytopenic patients, infants, and animal models is problematic. We have developed a novel flow cytometry test of platelet aggregation, in which 10- to 25-fold lower platelet counts or sample volumes can be used, either of platelet-rich plasma or whole blood from human subjects or mice. This setup can be applied to test in small assay volumes the influence of a variety of stimuli, drugs, and plasma factors, such as antibodies, on platelet aggregation. The presented principle stands as a novel promising tool, which allows analysis of platelet aggregation in thrombocytopenic patients or infants, and facilitates studies in platelets obtained from experimental animal models without the need of special devices but a flow cytometer.

Leukocyte adhesion deficiency syndrome: report on the first case in Chile and South America.

CONTEXT: Adhesion molecule deficiency type 1 is a rare disease that should be suspected in any patient whose umbilical cord presents delay in falling off, and who presents recurrent severe infections. Early diagnostic suspicion and early treatment improve the prognosis. CASE REPORT: The case of a four-month-old boy with recurrent hospitalizations because of severe bronchopneumonia and several episodes of acute otitis media with non-purulent drainage of mucus and positive bacterial cultures is presented. His medical history included neonatal sepsis and delayed umbilical cord detachment. Laboratory studies showed marked leukocytosis with predominance of neutrophils and decreased CD11b and CD18. These were all compatible with a diagnosis of leukocyte adhesion deficiency type I [LAD type 1].

Prenatal diagnosis of LAD-I on cord blood by flowcytometry.

OBJECTIVES: To optimize a simple flowcytometric technique for Prenatal diagnosis (PND) for Leukocyte adhesions defect (LAD-I) on cordocentesis sample at 18 wk gestation. METHODS: Normal reference ranges for expression of CD18/CD11-integrins in neutrophils and lymphocytes at 18 wk of gestation were established by flowcytometry. PND for LAD-I was then performed on the cordocentesis samples in three 'at risk' pregnancies after ruling out maternal contamination. RESULTS: CD18 and CD11a expression on fetal lymphocytes were found to be the most useful parameters for PND of LAD-I. All the three fetuses tested showed normal expression of CD18/CD11-integrins and thus were unaffected. This was confirmed by testing the cord blood (CB) samples after delivery and normal growth and absence of serious infections on follow-up. CONCLUSIONS: Flowcytometry offers a rapid and sensitive technique for PND of LAD-I in the absence of facilities for molecular diagnosis. Obstetricians, even in developing countries with modest facilities, can offer considerable relief for the families.

Clinical profile of leukocyte adhesion deficiency type I.

Leukocyte adhesion deficiency type I (LAD-I) is a rare, inherited immunodeficiency with defect in the recruitment of leukocyte to the site of inflammation. Patients with severe LAD-I have absent or markedly reduced expression of CD18 and CD11. Here we report clinical profile of 7 cases of LAD-I diagnosed at our center over a period of 3 years. Recurrent skin and mucous membrane infections were the major presenting manifestations. All children had a history of delayed cord separation.

Leukocyte adhesion deficiency-I variant syndrome (LAD-Iv, LAD-III): molecular characterization of the defect in an index family.

Leukocyte adhesion deficiencies are rare clinical syndromes of impaired host defense that provide novel insights into regulation of immune and inflammatory responses. Leukocyte adhesion deficiency (LAD)-I variant (LAD-Iv), also called LAD-III, is a unique disorder in which inside-out signaling of ß1, ß2, and ß3 integrins on leukocytes and platelets is disrupted, leading to impaired cellular adhesion, recurrent infections, and bleeding. We originally reported the second patient with this disorder to be identified and characterized the adhesive deficiencies and functional phenotype of this subject's leukocytes. Here, we show that the molecular defect in this index subject is a new mutation in FERMT3 (KINDLIN-3) which encodes KINDLIN-3, a cytoskeletal protein that interacts with the cytoplasmic tails of ß1, ß2, and ß3 integrins and is required for inside-out and outside-in signaling of these heterodimers. We also report clinical features and previously unrecognized defects in cells from a new patient, a sibling of the original subject that we described who carries the same FERMT3 mutation. Mutations in FERMT3 have now been shown to be the basis for LAD-Iv/LAD-III in each of the four original patients or families that established this syndrome, including the family that we describe.

Hematologically important mutations: leukocyte adhesion deficiency (first update).

Leukocyte adhesion deficiency (LAD) is an immunodeficiency caused by defects in the adhesion of leukocytes (especially neutrophils) to the blood vessel wall. As a result, patients with LAD suffer from severe bacterial infections and impaired wound healing, accompanied by neutrophilia. In LAD-I, mutations are found in ITGB2, the gene that encodes the ß subunit of the ß(2) integrins. This syndrome is characterized directly after birth by delayed separation of the umbilical cord. In the rare LAD-II disease, the fucosylation of selectin ligands is disturbed, caused by mutations in SLC35C1, the gene that encodes a GDP-fucose transporter of the Golgi system. LAD-II patients lack the H and Lewis Le(a) and Le(b) blood group antigens. Finally, in LAD-III (also called LAD-I/variant) the conformational activation of the hematopoietically expressed ß integrins is disturbed, leading to leukocyte and platelet dysfunction. This last syndrome is caused by mutations in FERMT3, encoding the kindlin-3 protein in all blood cells that is involved in the regulation of ß integrin conformation.

Leukocyte adhesion deficiency syndrome: report on the first case in Chile and South America / Síndrome de deficiencia de adhesión leucocitaria: informe del primer caso en Chile y América del Sur

CONTEXT: Adhesion molecule deficiency type 1 is a rare disease that should be suspected in any patient whose umbilical cord presents delay in falling off, and who presents recurrent severe infections. Early diagnostic suspicion and early treatment improve the prognosis. CASE REPORT: The case of a four-month-old boy with recurrent hospitalizations because of severe bronchopneumonia and several episodes of acute otitis media with non-purulent drainage of mucus and positive bacterial cultures is presented. His medical history included neonatal sepsis and delayed umbilical cord detachment. Laboratory studies showed marked leukocytosis with predominance of neutrophils and decreased CD11b and CD18. These were all compatible with a diagnosis of leukocyte adhesion deficiency type I [LAD type 1].

CONTEXTO: El deficit de moleculas de adhesión tipo 1 es una enfermedad rara que debe ser sospechada en todo paciente que presente un retardo en la caída del cordón unmbilical, además de infecciones graves a repetición. Un sospecha diagnóstica precoz y un tratamiento oportuno mejorarán el pronóstico. INFORMES DE CASO: Se presenta el caso de un niño de cuatro meses de edad, con hospitalizaciones recurrentes a causa de bronconeumonía severa y varios episodios de otitis media aguda con drenaje mucoso, no purulento, y cultivos bacterianos positivos. Su historial médico incluye la sepsis neonatal y el desprendimiento tardío del cordón umbilical. Los estudios de laboratorio mostraron leucocitosis marcada con predominio neutrofílico y disminución de CD11b y CD18, todos compatibles con el diagnóstico del tipo de deficiencia de adhesión leucocitaria 1 [tipo LAD 1].

Novel integrin-dependent platelet malfunction in siblings with leukocyte adhesion deficiency-III (LAD-III) caused by a point mutation in FERMT3.

Leukocyte adhesion deficiency-III (LAD-III) also called leukocyte adhesion deficiency-1/variant (LAD1v) is a rare congenital disease caused by defective integrin activation of leukocytes and platelets. Patients with LAD-III present with non-purulent infections and increased bleeding symptoms. We report on a novel integrin-dependent platelet dysfunction in two brothers with LAD-III syndrome caused by a homozygous mutation 1717C>T in the FERMT3 gene leading to a premature stop codon R573X in the focal adhesion protein kindlin-3. Stimulation of patients platelets with all used agonists resulted in a severely decreased binding of soluble fibrinogen indicating a defect in inside-out activation of the integrin alpha(IIb) beta(3) (GPIIb/IIIa). Patients platelets did not respond to the alpha(2)beta(1)-integrin agonist aggretin-A at all. Our data on granula secretion indicate for the first time that the thrombin receptor PAR-4 but not PAR-1 may be important in integrin-triggered granule secretion in response to thrombin. In contrast, collagen mediated platelet granule secretion was not affected in LAD-III-patients. Thus, integrin-signalling may be not essential in collagen-induced granule secretion. The patients' peripheral blood mononuclear cells showed a severe loss of adhesion capacity to VCAM-1 and to endothelial cells compared to cells from healthy donors. Rap-1 activation after PMA stimulation could be observed in controls but not in patients cells. After haematogenesis stem cell transplantation (HSCT) the brothers showed no symptoms of bleeding or immunodeficiency and the integrin-dependent platelet and leukocyte functions normalised.

Leukocyte adhesion deficiency type 1: an important consideration in the clinical differential diagnosis of prepubertal periodontitis. A case report and review of the literature.

Leukocyte adhesion deficiency type 1 (LAD-1) is a rare, inherited immunodeficiency that affects 1 in 1 million people yearly and usually presents with recurrent, indolent bacterial infections of the skin, mouth, and respiratory tract and impaired pus formation and wound healing. Features of this disease result from mutations in the region of the CD18 gene, which is encoded on chromosome 21q22.3. This gene codes for the common subunit of the leukocyte integrins LFA-1, Mac 1, and p150,95. Failure to produce a functional subunit results in the defective expression of all 3 leukocyte integrins, and the leukocytes of LAD have subnormal adhesion properties. We present a case of the moderate-to-severe form of LAD in a 3-year-old girl who initially presented with generalized swelling and erythema of the gingiva, with slight tooth mobility and a nonhealing labial ulceration. Her medical history was significant for recurrent urinary tract infections. Periodontal pathogens, including Capnocytophaga, Eikenella corrodens, and Candida albicans, were cultured. The patient had a significantly elevated white blood cell count and absolute neutrophil count. The diagnosis of LAD was confirmed with flow cytometry, which revealed significantly decreased subunits. Twenty-four months after the diagnosis was made and after a series of granulocyte transfusions and bone marrow transplantations, she expired as the result of respiratory failure.

Very low levels of donor CD18+ neutrophils following allogeneic hematopoietic stem cell transplantation reverse the disease phenotype in canine leukocyte adhesion deficiency.

Children with the severe phenotype of the genetic immunodeficiency disease leukocyte adhesion deficiency or LAD experience life-threatening bacterial infections because of molecular defects in the leukocyte integrin CD18 molecule and the resultant failure to express the CD11/CD18 adhesion molecules on the leukocyte surface. Hematopoietic stem cell transplantation remains the only definitive therapy for LAD; however, the degree of donor chimerism and particularly the number of CD18(+) donor-derived neutrophils required to reverse the disease phenotype are not known. We performed nonmyeloablative hematopoietic stem cell transplantations from healthy matched littermates in 9 dogs with the canine form of LAD known as CLAD and demonstrate that in the 3 dogs with the lowest level of donor chimerism, less than 500 CD18(+) donor-derived neutrophils/microL in the peripheral blood of the CLAD recipients resulted in reversal of the CLAD disease phenotype. These results demonstrate the value of a disease-specific, large-animal model for identifying the lowest therapeutic level required for successful cellular and gene therapy.

Chemotaxis of non-compressed blood polymorphonuclear leukocytes from an adolescent with severe leukocyte adhesion deficiency.

We have defined the defect in a child with severe leukocyte adhesion deficiency-1 (LAD) as resulting from a single amino acid shift in CD18 (from a C to T mutation at position 533) that prevents heterodimerization with the CD11 antigens to produce beta(2) integrins-the first reported patient homozygous for this defect. Although beset by frequent infections, the patient has survived to adolescence despite the lack of these important adhesion molecules. Consistent with his clinical course is the ability of his PMN to respond chemotactically in slide preparations, albeit with difficulty because of their poor purchase on substrate. The operant adhesins are unknown; his polymorphonuclear leukocytes (PMN) remain chemotactically responsive in the presence of antibodies to alphavbeta(3) and beta(1) integrins and to integrin-associated protein (IAP). These findings indicate that not all patients with severe LAD are candidates for early bone marrow transplantation.

A novel genetic leukocyte adhesion deficiency in subsecond triggering of integrin avidity by endothelial chemokines results in impaired leukocyte arrest on vascular endothelium under shear flow.

Leukocyte arrest on vascular endothelium under disruptive shear flow is a multistep process that requires in situ integrin activation on the leukocyte surface by endothelium-displayed chemoattractants, primarily chemokines. A genetic deficiency of leukocyte adhesion to endothelium associated with defective beta2 integrin expression or function (LAD-1) has been described. We now report a novel severe genetic disorder in this multistep process associated with functional defects in multiple leukocyte integrins, reflected in recurrent infections, profound leukocytosis, and a bleeding tendency. This syndrome is associated with an impaired ability of neutrophil and lymphocyte beta1 and beta2 integrins to generate high avidity to their endothelial ligands and arrest cells on vascular endothelium in response to endothelial chemoattractant signals. Patient leukocytes roll normally on endothelial selectins, express intact integrins and G protein-coupled chemokine receptors (GPCR), spread on integrin ligands, and migrate normally along a chemotactic gradient. Activation of beta2 integrins in response to GPCR signals and intrinsic soluble ligand binding properties of the very late activation antigen-4 (VLA-4) integrin are also retained in patient leukocytes. Nevertheless, all integrins fail to generate firm adhesion to immobilized ligands in response to in situ GPCR-mediated activation by chemokines or chemoattractants, a result of a primary defect in integrin rearrangement at ligand-bearing contacts. This syndrome is the first example of a human integrin-activation deficiency associated with defective GPCR stimulation of integrin avidity at subsecond contacts, a key step in leukocyte arrest on vascular endothelium under shear flow.

Defective migration of monocyte-derived dendritic cells in LAD-1 immunodeficiency.

beta2 Integrins (CD18) are required for leukocyte migration. In fact, the absence of CD18 results in type-1 leukocyte adhesion deficiency (LAD-1). We analyzed the distribution phenotype and function of dendritic cells (DCs) in three LAD-1 patients with homozygous mutations of CD18. Two of them did not express CD18 (Patients A and C), and the other subject (Patient B) displayed reduced expression of beta2 integrins because of a missense mutation. Analysis of DCs derived from Patients A and B showed an abnormal morphology and a severe impairment in transendothelial migration and chemotactic response to CCL19/macrophage inflammatory protein-3beta, suggesting that CD18 is required for migration of monocyte-derived DCs. Nevertheless, DCs displayed normal macropinocytosis and underwent normal maturation after addition of tumor necrosis factor alpha. Finally, immunohistochemical analysis of lymph nodes from subjects B and C revealed a significant reduction in the number of factor-XIIIa(+) interstitial DCs in the interfollicular area in both patients, suggesting that CD18 plays a role in the migration of these cells in vivo.

Analysis of serum cytokine profile in a holstein heifer with leukocyte adhesion deficiency which survived for long period.

Serum cytokine levels and their expression of mRNA on neutrophils from a bone marrow (BM) transplanted heifer with leukocyte adhesion deficiency were evaluated. The clinical condition of the affected heifer was relatively stable after BM-transplantation. Persistent hyper gamma-globulinemia and increased serum immunoglobulin G (IgG) concentrations were monitored longitudinally. The concentration of interleukin (IL)-1beta in serum from the affected heifer ranged from 15.8 to 321.7 ng/ml, and maximum concentration occurred at the time which coincided with peak IL-6. Serum levels of IL-6 ranged from 0.32 to 27.9 ng/m l, and they appeared to be associated with the increment of serum IgG in the affected heifer. mRNAs for IL-1beta, IL-6, IL-8 and granulocyte and macrophage colony stimulating factor (GM-CSF) were increased in neutrophils from the affected heifer compared to controls. Persistent hyper gamma-globulinemia of the affected heifer appeared to be associated with enhanced mRNA expression for IL-6 and its serum levels. These findings suggest that humoral immunity of the affected heifer is activated and the production of neutrophils appears to be enhanced under the incapability of beta(2) integrin-mediated functions of phagocytic cells.

Cytokine profile of a Holstein calf with bovine leukocyte adhesion deficiency during the acute-phase inflammatory response.

Changes in interleukin (IL)-1beta, IL-6 and IL-8 in serum, and their mRNA expression on neutrophils from a 4.6-month old Holstein young calf with bovine leukocyte adhesion deficiency (BLAD) during the acute phase were evaluated. IL-1beta concentrations in the serum of the calf with BLAD at age 143-162 days ranged from 8.7 to 16.6 ng/ml, whereas the values were less than 2.7 ng/ml in control calves. Serum IL-6 (0.04 ng/ml) was only detected on the 1st day when the animal was diagnosed with the BLAD. IL-1beta and IL-8 mRNA expression on neutrophils from the affected calf appeared to be similar to those of controls. Serum cytokine levels and their mRNA expression on neutrophils from the calf with BLAD appeared to be little affected by the deficient expression of beta(2)-integrin on leukocytes, and are considered to be modulated by the inflammatory stimuli.

Two distinct receptors mediate nonopsonic phagocytosis of different strains of Pseudomonas aeruginosa.

Complement receptor 3 (CR3) mediates both opsonic and nonopsonic phagocytosis of bacteria. Leukocyte adhesion deficiency (LAD) allows for the study of CR3-dependent phagocyte-bacterial ingestion, since LAD phagocytes do not express this receptor. Phagocytes from an infant with LAD were unable to ingest 50% of the Pseudomonas aeruginosa strains studied, which indicates a requirement for CR3. However, the remaining strains were phagocytosed in the absence of CR3, and ingestion was blocked by monoclonal antibodies directed at CD14. This CR3/CD14 receptor bias was further confirmed by using thioglycollate-elicited murine peritoneal macrophages, which have nonfunctional CR3 before activation. Results indicate that either CR3 or CD14 is involved independently in nonopsonic phagocytosis of different P. aeruginosa strains. Clearance of P. aeruginosa from the endobronchial space may be facilitated by nonopsonic phagocytosis, since low levels of opsonins are present. The impact of lung infection with P. aeruginosa may be determined, in part, by the phagocytic receptor that mediates ingestion.