AA genotype of IL‐8 −251A/T is associated with low PaO2/FiO2 in critically ill patients and with increased IL‐8 expression

Background and Objective: Interleukin‐8 (IL‐8) is a central chemokine in acute respiratory distress syndrome (ARDS), and the IL‐8 gene contains a functional single nucleotide polymorphism (SNP) ?251A/T in its promoter region. We hypothesized that IL‐8 ?251A/T SNP is associated with PaO₂/FiO₂ in critically ill patients. Methods: We conducted genetic‐association studies in intensive care units at academic teaching centres using a derivation septic shock cohort (vasopressin and septic shock trial (VASST), n = 467) and a validation post‐cardiopulmonary bypass surgery cohort (CPB, n = 739) of Caucasian patients. Patients in both cohorts were genotyped for IL‐8 ?251A/T. The primary outcome variable in both cohorts was the fraction of patients who had a PaO₂/FiO₂ < 200. IL‐8 mRNA expression was measured in genotyped lymphoblastoid cells in vitro. Results: The frequency of the patients with PaO₂/FiO₂ <200 was significantly greater in patients who had the AA genotype of ?251A/T than in patients who had the AT or TT genotypes in both VASST (AA = 60.8% vs AT and TT = 53.8% and 48.0%, P = 0.038) and the CPB cohort (AA = 37.0% vs AT and TT = 27.0% and 26.0%, P = 0.039). Patients having the AA genotype had a higher probability to remain on mechanical ventilation (P = 0.047) in the first 14 days. Lymphoblastoid cells having the AA genotype had significantly higher IL‐8 mRNA expression than cells having the AT or TT genotype (P = 0.022). Conclusions: Critically ill Caucasian patients who had the AA genotype of IL‐8 ?251A/T had an increased risk of PaO₂/FiO₂ <200. The AA genotype was associated with greater IL‐8 mRNA expression than the AT or TT genotypes.     

Syngeneic transplantation with peripheral blood mononuclear cells collected after the administration of recombinant human granulocyte colony-stimulating factor

Five syngeneic transplants were performed in four patients following myeloablative therapy using unmodified peripheral blood mononuclear cells (PBMCs) collected after the administration of recombinant human granulocyte colony stimulating factor (rhG-CSF) to normal donors. The only toxicity experienced by the four normal donors was bone pain. Four patients received two collections of PBMCs, and a second transplant was performed in one patient with one collection. The patients received a median of 20.53 x 10(8) total nucleated cells/kg (range 20 to 25.5), 11.3 x 10(8) total mononuclear cells/kg (range 6.52 to 17.2), 113.1 x 10(4)/kg CFU-GM (range 46.7 to 211.8) and 9.6 x 10(6) CD34+ cells/kg (range 1.6 to 12.6) Post-transplant growth factors were not administered. The median time to an absolute neutrophil count greater than 0.5 x 10(9)/L was 14 days (range 10 to 18). The median time to platelet transfusion independence was 11 days (range 10 to 13). Two patients had the number of CD3+ T lymphocytes determined in the pheresis product. An average of 3.04 x 10(10) CD3+ cells were collected per pheresis. This represents an approximate 1 log increase over the number of T lymphocytes in a typical bone marrow transplant. Rh-GCSF can be used to mobilize peripheral blood progenitor cells from normal donors with minimal toxicity. Studies of allogeneic transplants using PBMCs collected after rhG-CSF administration to determine permanent grafting ability and the incidence and severity of graft-versus-host disease are warranted.     

Mature liver stages of cloned Plasmodium falciparum share epitopes with proteins from sporozoites and asexual blood stages

The liver merozoites of malaria parasites are of paramount importance, as they initiate the parasite invasion of red blood cells and start the cycle associated with the clinical features of malaria. Investigating liver merozoite antigen is difficult because of the lack of a rodent model of human malaria. In addition, only a low proportion of cells are obtained in vivo, the parasites from Cebus and Aotus monkeys are immature, and in-vitro experiments with liver cells are often confounded by contamination with the natural mosquito flora copurified with the sporozoites used for seeding the liver cultures. In our study, mature liver schizonts were shown to possess many of the antigenic determinants recognized by MoAbs and sera specific for defined sporozoite and blood-stage antigens. We employed an immunofluorescence procedure based on evaluating parasites in cryosections prepared from infected chimpanzee liver. Sufficient numbers of sectioned parasites were evaluated with each antibody to assure the reproducibility of the results, and the fixation procedure used was sufficiently non-destructive to parasite antigens so that clear differences between reactions of specific antibodies and negative controls were observed. Our evidence for sharing of epitopes by liver merozoites and sporozoites or by liver merozoites and asexual blood-stage parasites raises the possibility that immune responses elicited against sporozoites or asexual stage antigens being considered as vaccine candidates may also act against this important, little-studied stage of the parasite.     

Idiopathic CD4 Lymphocytopenia: Clinical and Immunologic Characteristics and Follow-Up of 40 Patients

Idiopathic CD4 T lymphocytopenia (ICL) is a rare and severe condition with limited available data. We conducted a French multicenter study to analyze the clinical and immunologic characteristics of a cohort of patients with ICL according to the Centers for Disease Control criteria.We recruited 40 patients (24 female) of mean age 44.2 ± 12.2 (19–70) years. Patients underwent T-lymphocyte phenotyping and lymphoproliferation assay at diagnosis, and experiments related to thymic function and interferon (IFN)-γ release by natural killer (NK) cell were performed. Mean follow-up was 6.9 ± 6.7 (0.14–24.3) years. Infectious, autoimmune, and neoplastic events were recorded, as were outcomes of interleukin 2 therapy.In all, 25 patients had opportunistic infections (12 with human papillomavirus infection), 14 had autoimmune symptoms, 5 had malignancies, and 8 had mild or no symptoms. At the time of diagnosis, the mean cell counts were as follows: mean CD4 cell count: 127/mm³ (range, 4–294); mean CD8: 236/mm³ (range, 1–1293); mean CD19: 113/mm³ (range, 3–547); and mean NK cell count: 122/mm³ (range, 5–416). Most patients had deficiency in CD8, CD19, and/or NK cells. Cytotoxic function of NK cells was normal, and patients with infections had a significantly lower NK cell count than those without (p = 0.01). Patients with autoimmune manifestations had increased CD8 T-cell count. Proliferation of thymic precursors, as assessed by T-cell rearrangement excision circles, was increased. Six patients died (15%). CD4 T-cell count <150/mm³ and NK cell count <100/mm³ were predictors of death.In conclusion, ICL is a heterogeneous disorder often associated with deficiencies in CD8, CD19, and/or NK cells. Long-term prognosis may be related to initial CD4 and NK cell deficiency.Abbreviations: AIHA = autoimmune hemolytic anemia, CDC = Centers for Disease Control, CMV = cytomegalovirus, cpm = count per minute, CVID = common variable immunodeficiency, CXCR4 = C-X-C chemokine receptor type 4, HIV = human immunodeficiency virus, HLA = human leukocyte antigen, HPV = human papillomavirus, HTLV-1/2 = human T-cell lymphotropic 1/2, ICL = idiopathic CD4 T lymphocytopenia, IFN-γ = interferon-γ, IL = interleukin, JC virus = John Cunningham virus, LPA = lymphocyte proliferation assay, NK = natural killer, P = patient, PBMC = peripheral blood mononuclear cell, Pwd = pokeweed, SI = stimulation index, sj = signal joint, TREC = T-cell rearrangement excision circle     

Coeliac disease,epilepsy, and cerebral calcifications: association with TG6 autoantibodies

A 4‐year‐old boy presented with occipital seizures but normal initial neuroimaging and proved refractory to antiepileptic medications. On repeat neuroimaging after 1 year, he had developed bi‐occipital calcification and was then found to have positive coeliac serology. He was diagnosed with coeliac disease, epilepsy, and cerebral calcifications (CEC) and became seizure free after starting the gluten‐free diet. Positive antibody binding to neurons and glia was demonstrated on indirect immunofluorescence. High levels of immunoglobulin‐A directed against transglutaminase isoenzyme 6 (TG6) were found in the patient’s serum. The positive response to the diet, TG6 antibodies, and neuronal antibody binding suggest that CEC might be autoimmune in nature, as in other extra‐intestinal manifestations of gluten‐related diseases, such as gluten ataxia.