1/81. Homozygous deletion of the CYP21A-TNXA-RP2-C4B gene region conferring C4B deficiency associated with recurrent respiratory infections.The central class III region of the human major histocompatibility complex contains highly polymorphic genes that are associated with immune disorders and may serve as susceptibility factors for viral infections. Many HLA haplotype specific rearrangements, duplications, conversions and deletions, occur frequently in the C4 gene region. Genetic deficiencies of complement components are associated with recurrent occurrence of bacterial infections. We have studied the complement profile and the class III genes 5'-RP1-C4A-CYP21A-TNXA-RP2-C4B-CYP21B-TNXB -3' in a 4-year-old Caucasian patient. He has suffered from several pneumonias caused by respiratory viruses, eight acute otitis media, prolonged respiratory infections and urinary tract infection. complement c4 was constantly low, but the other complement components, from C1 to C9, C1INH, factor B and properdin, were within normal limits. Immunological evaluation gave normal lymphocyte numbers and functions with the exception of subnormal T cell response to pokeweed mitogen. Molecular studies of the C4 gene region in the patient revealed homozygous deletion of CYP21A-TNXA-RP2-C4B generating total deficiency of C4B and the flanking 5' region up to C4A, and in the father a missing CYP21A gene. Further investigations are needed to elucidate the relationship between C4B deficiency and susceptibility to infections.- - - - - - - - - - ranking = 1keywords = bacterial infection (Clic here for more details about this article) |
2/81. listeria monocytogenes and recurrent mycobacterial infections in a child with complete interferon-gamma-receptor (IFNgammaR1) deficiency: mutational analysis and evaluation of therapeutic options.We describe the history of a girl with interferon-gamma-receptor (IFNgammaR1) deficiency and studies performed to identify the molecular and clinical characteristics of this recently discovered disorder. This is the first report of a child from Northern europe with IFNgammaR1 deficiency. The patient, now 7 years old, first presented with swelling and reddening at the Bacille Calmette-Guerin (BCG) vaccination site, swelling of lymph nodes, hepatomegaly, and an unusually severe varicella rash at the age of 4 months. At that time, she was diagnosed with BCG histiocytosis without typical granuloma formation and was treated with antituberculous agents. During the clinical course of her illness, several different types of atypical mycobacteria and (for the first time in an IFNgammaR1-deficient patient) listeria monocytogenes were detected. Flow cytometric analysis showed that the patient's monocytes could not bind a monoclonal antibody specific for the IFNgamma-receptor. Our analysis of mRNA derived from the alpha-chain (IFNgammaR1) gene of this receptor revealed deletions of 173 bp and 4 bp in cDNA sequences originating from individual alleles. The 173 bp deletion was located between nucleotide positions 200 and 372, exactly matching those of exon 3, and the 4 bp deletion was located between nucleotide positions 561 and 564 of the coding region of the cDNA. Analysis of genomic dna revealed the presence of a G to T transition at the 5'end of the splice consensus sequence of intron 3, which explains the absence of exon 3. The other allele carried the 4-base-pair deletion (ACTC) at nucleotide positions 15-18 of exon 5. Twelve months after an allogeneic bone marrow transplantation, the patient had clinically improved.- - - - - - - - - - ranking = 4keywords = bacterial infection (Clic here for more details about this article) |
3/81. Absence of MHC class II gene expression in a patient with a single amino acid substitution in the class II transactivator protein CIITA.We investigated the underlying genetic defect in an immunodeficient patient who presented with recurrent bacterial infections in his late twenties and demonstrated a transcriptional defect in major histocompatibility complex (MHC) class II regulation. Transient heterokaryon analysis implicated functional loss of CIITA, the MHC class II transactivator protein, and in support of this MHC class II antigen expression was restored by stable transfection with the wild-type molecule. A single amino acid substitution, phenylalanine to serine, in the COOH-terminal portion of the CIITA sequence correlated with reduced transcription of both classical (HLA-DP, -DQ, and -DR) and nonclassical (HLA-DM and -DO) class II genes. The long survival of the patient, although remarkable, was not associated with partial CIITA function as evidenced by residual MHC class II expression. These data define at high resolution a region of CIITA that is essential for function in both professional and nonprofessional antigen presenting cells and which could potentially constitute a target for therapeutic intervention by novel factors with a propensity to downregulate MHC class II antigen expression.- - - - - - - - - - ranking = 1keywords = bacterial infection (Clic here for more details about this article) |
4/81. constipation presenting as recurrent vulvovaginitis in prepubertal children.vulvovaginitis is the most common gynecologic problem in premenarcheal girls. We describe 3 patients with recurrent vulvovaginitis caused by bacterial infection who responded to treatment of constipation with resolution of the vulvovaginitis. There were no recurrences during the follow-up period of 15 to 36 months. We propose that underlying constipation should be added to the list of possible causes of recurrent vulvovaginitis.- - - - - - - - - - ranking = 1keywords = bacterial infection (Clic here for more details about this article) |
5/81. Molecular and cytogenetic remission in a case of subtype M4E acute myelogenous leukemia with minimal monochemotherapy: high sensitivity or spontaneous remission?Complete remission was observed in an adult patient with acute myelogenous leukemia after minimal monochemotherapy. Remission occurred after a severe febrile pneumonia and was accompanied by cytogenetic and molecular remission. The hypothesis of spontaneous remission was raised, even if a high sensitivity to low-dose cytostatics cannot be excluded. Such spontaneous complete remissions, often associated with bacterial infections and blood transfusions, are extremely rare, and are usually of short duration. Previous cases are summarized, and the role of etiologic factors is discussed.- - - - - - - - - - ranking = 1keywords = bacterial infection (Clic here for more details about this article) |
6/81. Large granular lymphocyte leukemia and its association with oral neutropenic ulcerations: a case report.Large granular lymphocyte leukemia is a rare chronic indolent disorder commonly associated with severe neutropenia. The pathogenesis of the neutropenia is unclear. A case is presented of a 74-year-old man who had recurrent oral ulcerations for over a year before a diagnosis was made. These recurrent oral ulcers cleared with treatment and have not returned. The differential diagnosis of persistent oral ulcerations includes trauma; viral, fungal, and bacterial infections; systemic disease; or various malignant conditions. The oral ulcers in this man were likely infectious in nature and related to the severe chronic neutropenia. This case serves to illustrate the potentially complex nature of oral ulcers.- - - - - - - - - - ranking = 1keywords = bacterial infection (Clic here for more details about this article) |
7/81. Familial CD8 deficiency due to a mutation in the CD8 alpha gene.CD8 glycoproteins play an important role in both the maturation and function of MHC class I-restricted T lymphocytes. A 25-year-old man, from a consanguineous family, with recurrent bacterial infections and total absence of CD8( ) cells, was studied. Ab deficiencies and ZAP-70 and TAP defects were ruled out. A missense mutation (gly90-->ser) in both alleles of the immunoglobulin domain of the CD8 alpha gene was shown to correlate with the absence of CD8 expression found in the patient and two sisters. Conversely, high percentages of CD4(-)CD8(-)TCR alpha beta( ) T cells were found in the three siblings. A novel autosomal recessive immunologic defect characterized by absence of CD8( ) cells is described. These findings may help to further understanding of the role of CD8 molecules in human immune response.- - - - - - - - - - ranking = 1keywords = bacterial infection (Clic here for more details about this article) |
8/81. Epstein-Barr virus-associated recurrent necrotic papulovesicles with repeated bacterial infections ending in sepsis and death: consideration of the relationship between Epstein-Barr virus infection and immune defect.The disease of Epstein-Barr virus (EBV) -associated recurrent necrotic papulovesicles is a distinct clinicopathologic entity different from classic hydroa vacciniforme (HV). A few patients have been reported as atypical HV with systemic involvement, development of lymphoma, and poor prognosis. We describe a patient with recurrent necrotic papulovesicles and multiple varioliform scars in both sun-exposed and covered areas. In contrast to cases of previously reported atypical HV, our patient suffered from repeated bacterial infections on various sites ending in sepsis and death, but without malignant transformation. EBV was detected in the lymphoid cells from the skin lesions by anti-latent membrane protein (LMP) antibody and in situ hybridization. We suggest that the repeated bacterial infections in this case raise the possibility of an association of EBV infection with increased susceptibility to bacterial infections.- - - - - - - - - - ranking = 7keywords = bacterial infection (Clic here for more details about this article) |
9/81. Recurrent pneumonia with mild hypogammaglobulinemia diagnosed as X-linked agammaglobulinemia in adults.BACKGROUND: X-linked agammaglobulinemia (XLA) is a humoral immunodeficiency caused by disruption of the Bruton's tyrosine kinase (BTK) gene. Typical XLA patients suffer recurrent and severe bacterial infections in childhood. methods: Flow cytometric analysis of the peripheral monocytes using the anti-BTK antibody was used to characterize a 27 year old male patient with mild hypogammaglobulinemia (IgG, 635 mg/dl; IgM, 11 mg/dl; IgA, <5 mg/dl). He had suffered from frequent pneumonia since age 25 but had no history of frequent infections in his childhood or in adolescence. Sequencing of the BTK cDNA obtained from an Epstein-Barr virus-transformed B lymphoblastoid cell line derived from the bone marrow of the patient was performed to confirm a genetic defect. RESULTS: Flow cytometric analysis of cytoplasmic BTK protein in peripheral monocytes indicated that the patient presents a rare case of adult-onset XLA and that his mother is an XLA carrier. Sequencing of the BTK gene revealed a deletion of AG in the codon for Glu605 (AGT), resulting in an aberrant stop codon that truncates the BTK protein in its kinase domain. CONCLUSIONS: This case suggests that some XLA cases may remain undiagnosed because they only show mild hypogammaglobulinemia and they lack repeated infections in childhood. Flow cytometric analysis is a powerful method to screen these patients.- - - - - - - - - - ranking = 1keywords = bacterial infection (Clic here for more details about this article) |
10/81. Anti-MPO-ANCA-positive microscopic polyangiitis following subacute bacterial endocarditis.Although infectious agents such as staphylococcus aureus have been implicated in the pathogenesis of Wegener's granulomatosis, the role of bacterial infections in the pathogenesis of other types of small-vessel vasculitides associated with antineutrophil cytoplasmic antibodies (ANCA) is less clear. We describe a patient who developed a non-granulomatous necrotising small vessel vasculitis and perinuclear ANCA (p-ANCA) directed against myeloperoxidase (MPO) after recurrent episodes of bacterial endocarditis due to Staph. aureus. Although cytoplasmic ANCA (c-ANCA) directed against proteinase 3 have been reported in single patients with bacterial endocarditis, to our knowledge this patient is the first reported case of an anti-MPO-ANCA positive systemic vasculitis following bacterial endocarditis.- - - - - - - - - - ranking = 1keywords = bacterial infection (Clic here for more details about this article) |
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