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Query: UMLS:C0027947 (neutropenia)
 17,527 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The acronym WHIM refers to Warts, Hypogammaglobulinemia, Infections, and Myelokathexis. The latter refers to the retention of white cells in the marrow, which becomes hypercellular. We have found approximately 20 examples of WHIM syndrome in the literature under various designations; the first examples are Zuelzer [1964] and Krill et al. [1964]. Chronic noncyclic neutropenia and hypercellular bone marrow represent defective release of marrow cells into the peripheral stream (myelokathexis). The hypermature neutrophils are bizarre in form. Condensed nuclei connected by long, stringy filaments and vacuolated cytoplasm suggest apoptosis. Fever or other stress increases the release of neutrophils. Hypogammaglobulinemia is marked and associated with recurrent upper respiratory infections (sinusitis, tonsillitis, otitis media, pneumonia). Patients have numerous warts, some venereal, with resultant cervical and vulval premalignant dysplasia. We report on a kindred of 6 affected individuals in 3 generations with autosomal dominant WHIM syndrome. The sex ratio among reported patients and in our kindred is 17 female to 8 male. Because there had been no male-to-male transmssion, search of the entire X-chromosome including the pseudoautosomal area was carried out and no linkage was found. Recently, the propositus has had an unaffected daughter, confirming our finding that the gene is not X-linked. A genome-wide search is being carried out.
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PMID:WHIM syndrome, an autosomal dominant disorder: clinical, hematological, and molecular studies. 1076 1

The study of inherited immunodeficiencies has proven valuable in elucidating molecular signaling cascades underlying the developmental and functional regulation of the human immune system. The first example of a human immunologic disease caused by mutation of a chemokine receptor was provided by WHIM (warts, hypogammaglobulinemia, infections, and myelokathexis) syndrome, a rare, combined immunodeficiency featuring an unusual form of neutropenia. Subsequent studies following the initial description of mutations in the CXCR4 gene have revealed a striking concordance in the types of mutations observed, suggesting that impaired regulation of receptor signaling by truncation of the cytoplasmic tail domain is an essential aspect in disease pathogenesis. Biochemical studies have provided support for the model that impaired receptor downregulation leads to the characteristic immunologic and hematologic disturbances. Interestingly, these genetic studies have also identified phenocopies with the same clinical features but without mutation of CXCR4, suggesting that mutations in as yet uncharacterized downstream regulators of the receptor may be involved in a proportion of cases.
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PMID:WHIM syndrome: a defect in CXCR4 signaling. 1609 Dec 5

The term WHIM syndrome (WHIMS) is an acronym describing a rare primary immunodeficiency disorder characterized by warts, hypogammaglobulinemia, immunodeficiency, and myelokathexis, the unusual association of neutropenia with bone marrow myeloid hypercellularity. WHIMS was recently associated with mutations in the gene encoding the chemokine receptor CXCR4 and as such is the first disease ascribed to abnormalities of chemokine signaling. We report a sporadic case of WHIMS in a woman presenting with recurrent infections and human papilloma virus-related genital dysplasia.
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PMID:Sporadic case of warts, hypogammaglobulinemia, immunodeficiency, and myelokathexis syndrome. 1627 83

Phaeoacremonium parasiticum is an agent of opportunistic phaeohyphomycosis belonging to a genus encompassing numerous recently described and soon-to-be-described, difficult-to-identify human pathogens. It appears in the literature to be an uncommon etiologic agent, yet we encountered several cases in a single year. Each presented problems in laboratory identification and case management. We present two cases of invasive disease with definite identification and susceptibility results. These cases are analyzed in relation to a brief review of previous cases known to have been caused by this species. Our first case involved a 40-year-old male cardiac transplant recipient with multiple localized skin lesions. The second featured a 31-year-old female with aplastic anemia and prolonged neutropenia who developed disseminated disease, with multiple positive blood cultures and skin lesions. Both patients died despite aggressive surgical and antifungal therapy. Fungal susceptibility testing showed that our isolates appeared to be susceptible to amphotericin B, itraconazole, voriconazole, ravuconazole, and posaconazole. Because phenotypic identification of Phaeoacremonium is notably problematic, sequence-based confirmation was performed using a recently proposed standard based on use of a segment of the 5' end of the beta-tubulin gene. Sequences from both isolates involved in the cases were over 99% similar to the corresponding sequence of the ex-type isolate of P. parasiticum. The close DNA similarity, corroborated by relevant morphological similarities (e.g., long, thin phialides and tuberculate hyphae bearing warts up to 3 mum high), confirms these two isolates as P. parasiticum.
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PMID:Phaeoacremonium parasiticum infections confirmed by beta-tubulin sequence analysis of case isolates. 1675 22

Warts, hypogammaglobulinaemia, infections, myelokathexis (WHIM) syndrome is an inherited immune disorder associated with CXCR4 gene mutations. Recent studies suggested that impaired receptor downregulation and enhanced chemotactic responsiveness to stromal-derived factor-1 (SDF-1), the sole cognate ligand for CXCR4, may account for the characteristic features of WHIM patients. This study evaluated whether the interaction of SDF-1 with CXCR4 could block constitutive apoptosis of peripheral blood neutrophils from congenital neutropenia patients and controls. SDF-1 was found to be a potent anti-apoptotic factor for WHIM neutrophils harbouring a truncating CXCR4 mutation, but not for neutrophils from control individuals, thus supporting the notion that such mutations may confer enhanced functional responses.
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PMID:Stromal-derived factor-1 abolishes constitutive apoptosis of WHIM syndrome neutrophils harbouring a truncating CXCR4 mutation. 1689 28

WHIM(warts, hypogammaglobulinemia, recurrent bacterial infection, and myelokathexis) syndrome is a rare immunodeficiency caused in many cases by autosomal dominant C-terminal truncation mutations in the chemokine receptor CXCR4. A prominent and unexplained feature of WHIM is myelokathexis (hypercellularity with apoptosis of mature myeloid cells in bone marrow and neutropenia). We transduced healthy human CD34(+) peripheral blood-mobilized stem cells (PBSCs) with retrovirus vector encoding wild-type (wt) CXCR4 or WHIM-type mutated CXCR4 and studied these cells ex vivo in culture and after engraftment in a nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mouse xenograft model. Neither wt CXCR4 nor mutated CXCR4 transgene expression itself enhanced apoptosis of neutrophils arising in transduced PBSC cultures even with stimulation by a CXCR4 agonist, stromal cell-derived factor-1 (SDF-1 [CXCL12]). Excess wt CXCR4 expression by transduced human PBSCs enhanced marrow engraftment, but did not affect bone marrow (BM) apoptosis or the release of transduced leukocytes into PB. However, mutated CXCR4 transgene expression further enhanced BM engraftment, but was associated with a significant increase in apoptosis of transduced cells in BM and reduced release of transduced leukocytes into PB. We conclude that increased apoptosis of mature myeloid cells in WHIM is secondary to a failure of marrow release and progression to normal myeloid cell senescence, and not a direct effect of activation of mutated CXCR4.
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PMID:WHIM syndrome myelokathexis reproduced in the NOD/SCID mouse xenotransplant model engrafted with healthy human stem cells transduced with C-terminus-truncated CXCR4. 1694 1

WHIM (warts-hypogammaglobulinemia-infections-myelokathexis) syndrome is a recently described primary immunodeficiency disorder caused by mutation of the CXCR4 chemokine receptor gene. We report here of a 6.5-yr-old girl with bacterial infections, severe chronic neutropenia, and hypogammaglobulinemia. Sequencing the CXCR4 gene revealed a c.1013C > G sequence variant suggesting WHIM syndrome. Recurrent c.1013C > G sequence variant of the CXCR4 gene resulting in p.S338X truncation mutation of this chemokine receptor protein is first reported here.
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PMID:Recurrent CXCR4 sequence variation in a girl with WHIM syndrome. 1708 43

CXCR4 is a G protein-coupled chemokine receptor that has been implicated in the pathogenesis of primary immunodeficiency disorders and cancer. Autosomal dominant gain-of-function truncations of CXCR4 are associated with warts, hypo-gammaglobulinemia, infections, and myelokathexis (WHIM) syndrome, a primary immunodeficiency disorder characterized by neutropenia and recurrent infections. Recent progress has implicated CXCR4-SDF1 (stromal cell-derived factor 1) signaling in regulating neutrophil homeostasis, but the precise role of CXCR4-SDF1 interactions in regulating neutrophil motility in vivo is not known. Here, we use the optical transparency of zebrafish to visualize neutrophil trafficking in vivo in a zebrafish model of WHIM syndrome. We demonstrate that expression of WHIM mutations in zebrafish neutrophils induces neutrophil retention in hematopoietic tissue, impairing neutrophil motility and wound recruitment. The neutrophil retention signal induced by WHIM truncation mutations is SDF1 dependent, because depletion of SDF1 with the use of morpholino oligonucleotides restores neutrophil chemotaxis to wounds. Moreover, localized activation of a genetically encoded, photoactivatable Rac guanosine triphosphatase is sufficient to direct migration of neutrophils that express the WHIM mutation. The findings suggest that this transgenic zebrafish model of WHIM syndrome may provide a valuable tool to screen for agents that modify CXCR4-SDF1 retention signals.
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PMID:Live imaging of neutrophil motility in a zebrafish model of WHIM syndrome. 2094 86

The WHIM syndrome features susceptibility to human Papillomavirus infection-induced warts and carcinomas, hypogammaglobulinemia, recurrent bacterial infections, B and T-cell lymphopenia, and neutropenia associated with retention of senescent neutrophils in the bone marrow (i.e. myelokathexis). This rare disorder is mostly linked to inherited heterozygous autosomal dominant mutations in the gene encoding CXCR4, a G protein coupled receptor with a unique ligand, the chemokine CXCL12/SDF-1. Some individuals who have full clinical forms of the syndrome carry a wild type CXCR4 gene. In spite of this genetic heterogeneity, leukocytes from WHIM patients share in common dysfunctions of the CXCR4-mediated signaling pathway upon exposure to CXCL12. Dysfunctions are characterized by impaired desensitization and receptor internalization, which are associated with enhanced responses to the chemokine. Our increasing understanding of the mechanisms that account for the aberrant CXCL12/CXCR4-mediated responses is beginning to provide insight into the pathogenesis of the disorder. As a result we can expect to identify markers of the WHIM syndrome, as well as other disorders with WHIM-like features that are associated with dysfunctions of the CXCL12/CXCR4 axis.
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PMID:CXCL12/CXCR4-axis dysfunctions: Markers of the rare immunodeficiency disorder WHIM syndrome. 2117 77

WHIM syndrome is a dominantly inherited primary immunodeficiency disorder representing the first identified example of human disease caused by mutations in the gene encoding for the chemokine receptor CXCR4. Pathogenesis is mediated by CXCR4 hyperfunction, leading to increased responsiveness to its unique ligand CXCL12 (also known as SDF-1). The altered CXCR4/CXCL12 interaction likely impairs cellular homeostasis and trafficking, resulting in immunological dysfunctions. The acronym WHIM resumes the main features of the syndrome: Warts, Hypogammaglobulinemia, Infections and Myelokathexis, which is abnormal retention of mature neutrophils in the bone marrow. WHIM patients suffer from recurrent bacterial infections since childhood and manifest a specific susceptibility to HPV infections. Hematological findings include neutropenia, lymphopenia and hypogammaglobulinemia. Because of the rarity of the disease and the heterogeneity in clinical presentation, diagnosis is often delayed. In the majority of patients, the phenotype is incomplete at the onset and WHIM syndrome is not suspected. Early identification may improve clinical and therapeutic management. Symptomatic treatments include G-CSF, substitutive immunoglobulins and antibiotic prophylaxis. A new therapeutic strategy might include the potent inhibitor of CXCR4 function plerixafor (Mozobil), as an agent specifically targeting the molecular defect in order to attenuate the phenotypic manifestations of the syndrome.
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PMID:Clinical and genetic features of Warts, Hypogammaglobulinemia, Infections and Myelokathexis (WHIM) syndrome. 2150 20


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