Intestinal protothecosis in a patient with chronic mucocutaneous candidiasis.
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Biomedical subjects
Publications and source records attributed to M Rottem.
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The regulation of tissue mast cell number depends both on the rate of production of mast cell precursors from bone marrow and the length of survival of mature mast cells within tissues. Mast cells develop from bone marrow under the influence of both interleukin-3 (IL-3) and the c-kit ligand, also known as stem cell factor (SCF). In humans, the mast cell precursor is CD34+, FcERI-. Mast cell precursors with time become less responsive to IL-3 and more responsive to SCF. Mast cell proliferation directed by SCF is enhanced by other cytokines including both IL-4 and IL-10. Once mast cell precursors target to tissues, their survival may largely be dependent upon the local production of SCF. Withdrawal of IL-3 or SCF results in mast cell apoptosis; SCF rescues mast cells following IL-3 withdrawal. TGF-beta prevents this SCF rescue. Engagement of extracellular matrix by integrin receptors may also effect mast cell numbers. Thus, in the final analysis, mast cell numbers, while relatively constant in the normal state, may be up-regulated by altering the rate of their production centrally or length of survival in the periphery.
Mast cells may be cultured from human peripheral blood in the presence of recombinant human stem cell factor (rhSCF). The characteristics of the cells in peripheral blood that give rise to mast cells are unknown. Because mast cell precursors in human marrow are CD34+, human peripheral blood mononuclear cells from patients with mastocytosis and normal controls were sorted on the basis of CD34 expression and the positive and negative cell populations were cultured in rhSCF, recombinant human interleukin-3 (rhIL-3), or both for 6 weeks. Cell cultures were examined every 2 weeks for total and mast cell number and cell differential using Wright Giemsa and acid toluidine blue stains and antibodies to mast cell tryptase and chymase, cell-associated histamine, and expression of CD34, c-kit, Fc epsilon RI, and Fc gamma RII using flow cytometric analysis. The ultrastructural anatomy of mast cells was examined by electron microscopy. Peripheral blood CD34+ cells cultured in rhSCF with or without rhIL-3 gave rise to cell cultures consisting of greater than 80% mast cells by 6 weeks. CD34+ cells cultured in rhIL-3 alone did not give rise to mast cells, whereas rhIL-3 plus rhSCF increased the final mast cell number eightfold when compared with cells cultured in rhSCF alone. Mast cells increased concomitantly with a decrease in large undifferentiated mononuclear cells. CD34- cells did not give rise to mast cells. Histamine content per cell at 6 weeks was approximately 5 pg. Electron microscopy of 4-week cultures showed immature mast cells containing predominantly tryptase-positive granules that were either homogeneous or contained lattice structures, partial scroll patterns, or central dense cores and mixtures of vesicles, fine granular material, and particles. The CD34+ population at day 0 expressed Kit (65%) and Fc gamma RII (95%), but not Fc epsilon RI, by fluorescence-activated cell sorter analysis. At 6 weeks, CD34+-derived mast cells exhibited Fc epsilon RI in addition to Kit and Fc gamma RII, and were negative for CD34 antigen. Patients with mastocytosis showed a higher number of mast cells per CD34+ cell cultured compared with normal controls. Thus, the mast cell precursor in human peripheral blood is CD34+/Fc epsilon RI- and gives rise to mast cells in the presence of rhSCF with or without rhIL-3, and the number of mast cells arising per CD34+ cell in culture is greater when the CD34+ cells are obtained from patients with mastocytosis compared with normal subjects.
OBJECTIVE: To evaluate prospectively the clinical features, angiographic findings, and response to treatment of patients with Takayasu arteritis. DESIGN: 60 patients with Takayasu arteritis were studied at the National Institute of Allergy and Infectious Diseases between 1970 and 1990 and were followed for 6 months to 20 years (median follow-up, 5.3 years). MEASUREMENTS: Data on clinical features, angiographic and laboratory findings, disease course, and response to therapy were all recorded and stored in a computer-based retrieval system. SETTING: The Warren Magnuson Clinical Center of the National Institutes of Health. RESULTS: In our series of patients, Takayasu arteritis was more common in Asian persons compared with persons from other racial groups. Females (97%) were most frequently affected. The median age at disease onset was 25 years. Juveniles had a delay in diagnosis that was about four times that of adults. The clinical presentation ranged from asymptomatic to catastrophic with stroke. The most common clinical finding was a bruit. Hypertension was most often associated with renal artery stenosis. Only 33% of all patients had systemic symptoms on presentation. Sixty-eight percent of patients had extensive vascular disease; stenotic lesions were 3.6-fold more common than were aneurysms (98% compared with 27%). The erythrocyte sedimentation rate was not a consistently reliable surrogate marker of disease activity. Surgical bypass biopsy specimens from clinically inactive patients showed histologically active disease in 44% of patients. Although clinically significant palliation usually occurred after angioplasty or bypass of severely stenotic vessels, restenosis was common. Medical therapy was required for 80% of patients, whereas 20% had monophasic self-limiting disease. Immunosuppressive treatment with glucocorticoids alone or in combination with a cytotoxic agent failed to induce remission in one fourth of patients; about half of those who achieved remission later relapsed. CONCLUSIONS: In North America, Takayasu arteritis is a rare disease. It is heterogeneous in presentation, progression, and response to therapy. Current laboratory markers of disease activity are insufficiently reliable to guide management. Most patients require repeated and, at times, prolonged courses of therapy. Although mortality was low, substantial morbidity occurred in most patients.
OBJECTIVE: To identify the role of methotrexate (MTX) in the treatment of persistent or recurrent Takayasu arteritis that is refractory to treatment with glucocorticoids (GC) alone. METHODS: An open-label pilot study of weekly low-dose MTX+GC treatment was performed. Outcome was evaluated according to clinical characteristics, laboratory abnormalities, findings on routinely performed angiographic studies, and ability to withdraw GC and MTX therapy. Eighteen patients entered the study; 2 dropped out, and 16 were followed up for a mean period of 2.8 years (range 1.3-4.8 years). RESULTS: Weekly administration of MTX (mean stable dose of 17.1 mg) and GC resulted in remissions in 13 of 16 patients (81%). However, 7 patients (44%) had relapses as GC was tapered to or near discontinuation. Retreatment again led to remission, and 3 of 7 patients in this group have successfully stopped GC therapy. Of those patients who achieved remission, 8 (50%) have sustained remissions of 4-34 months (mean 18 months), and 4 of this group have not required GC or MTX therapy for 7-18 months (mean 11.3 months). Three patients experienced disease progression in spite of treatment. CONCLUSION: About half of all Takayasu arteritis patients have chronic active disease for which GC therapy alone does not provide sustained remissions that allow withdrawal of treatment. Weekly low-dose MTX is an effective means of inducing remission and minimizing GC therapy and toxicity in most of these patients. Further long-term studies will be required to assess the durability of remission and the need for maintenance MTX therapy in this subset of Takayasu arteritis patients.
Mouse bone marrow (BM) was cultured in the presence of recombinant mouse (rm) interleukin-3 (IL-3), rmIL-4, rmIL-5, rmIL-7, purified mouse (m) IL-9, rmIL-10, recombinant human (rh) macrophage-colony-stimulating factors (M-CSF), rm granulocyte-macrophage colony-stimulating factors (GM-CSF) rm stem cell factor (SCF), rh interferon-alpha (IFN-alpha), rmIFN-gamma, and mNGF to determine which cytokine would give rise to mast cells in murine BM cultures. From a starting population of 1 x 10(7) cells, 1.55 x 10(7) mast cells developed within 14 days in cultures supplemented by rmIL-3. No mast cells were seen at day 14 when any of the other cytokines were present alone, except for rmSCF, which supported the growth of < 0.01% of mast cells observed in IL-3-dependent BM cultures. When rmIL-4, -5, -7, -10, mIL-9, rhM-CSF, rmGM-CSF, rmSCF, rhIFN-alpha, -gamma, or mNGF were added to BM cultures in the presence of rmIL-3, mast cell growth increased 200% with the addition of rmSCF, and 10% when rmIL-4 or IL-9 was added. However, the addition of rhM-CSF, rmGM-CSF, rmIFN-gamma, and mNGF decreased the number of mast cells. Mast cell number, as determined by metachromatic stains, generally approximated the number of Fc epsilon RI+ cells as assessed by FACS analysis. Among the cytokines, only rmIL-4 and rmSCF were able to support the survival of mast cell progenitors in the absence of obvious mast cell proliferation, similarly to rmIL-3. Only rmSCF alone, or in combination with rmIL-3 or -4, supported the growth of mast cells from mouse peripheral blood mononuclear cells (PBMC) where the number of mast cell precursors was about 90 per 10(6) PBMC. With time, mouse BM cells cultured in rmIL-3 became more responsive to rmSCF. Taken together, these data demonstrate that IL-3 is a major early mast cell growth factor, that mast cells become more dependent on SCF with time, and that the effects of IL-3 and SCF are upregulated (IL-4) or downregulated (M-CSF, GM-CSF, IFN-gamma) by both growth factors and proinflammatory cytokines.
We observed systematic vasculitis (polyarteritis nodosa and Wegener's granulomatosis) in several members of 2 different families. Our experience and a review of the literature suggests that genetic factors are important but not sufficient to express clinical features of these diseases.
Stem cell factor (SCF) is known to alter the proteoglycans, proteases, and cytokines synthesized by mast cells and to activate basophils. To determine whether SCF could also effect the ultrastructural characteristics of basophils and mast cells, we examined the ultrastructure of these Fc epsilon RI+ cells over 42 days in IL-3-dependent murine bone marrow-derived cell cultures in the presence or absence of SCF. Initial experiments revealed that the addition of SCF to IL-3-dependent cells enhanced their proliferative rate without influencing the percentage of Fc epsilon RI+ or metachromatic cells. We next isolated the Fc epsilon RI+ cells using flow cytometry. Light microscopy of these cells revealed mixed cultures of both immature and mature mast cells and basophils with mature mast cells predominating by 3 wk. One hundred to 150 Fc epsilon RI+ cells were then photographed by electron microscopy at 3, 10, 21, and in some cases, 42 days of culture, and the ultrastructure of each cells was evaluated by morphometry. Each cell was scored as a mast cell or basophil using standard criteria. Analysis of this data revealed that SCF in the presence of IL-3 promoted the development of mast cells, although a significant number of basophils were noted at day 21 but were absent by day 42. When bone marrow cells cultured in IL-3 + SCF were compared with cells cultured in IL-3 alone, a significant decrease in cell and nuclear size and granule number and size was noted in both mast cells and basophils cultured in IL-3 + SCF, and basophils and mast cells under these conditions most resemble their in vivo counterparts. Thus, SCF in the presence of IL-3 increases the ratio of mast cells to basophils and alters the ultrastructural characteristics of mast cells and basophils toward a more mature phenotype.
We prospectively studied and compared clinical features, treatment, course of illness, and long-term morbidity and mortality rates for Wegener granulomatosis in 23 childhood-onset patients with those of 135 adult-onset patients who were studied concurrently. Treatment was usually provided with glucocorticoids and cyclophosphamide. The mean follow-up period was 8.7 years for childhood-onset and 7.6 years for adult-onset Wegener granulomatosis. Most aspects of Wegener granulomatosis were similar in childhood-onset and adult-onset patients. Permanent morbidity from disease occurred in 86% of both groups. However, some features were significantly different. Wegener granulomatosis in childhood-onset patients was complicated five times more often by subglottic stenosis and twice as often by nasal deformity. Treatment-related permanent morbidity occurred in 22% of childhood-onset patients and 45% of adult-onset patients. After similar periods of cyclophosphamide therapy and follow-up, cyclophosphamide-related malignancies were less likely (0% vs 11%) to have developed in childhood-onset patients. Although 89% of patients treated with glucocorticoids and cyclophosphamide had remission, prolonged delay in achieving remission and relapses led in both patient groups to freedom from active disease for approximately 50% of the total patient-years. As a result, morbidity was substantial and has led to comparative studies of alternative therapies.
Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a hematopoietic growth factor being used increasingly to support white blood cell counts in hematologic disorders. Since the survival of IgG-sensitized cells following blood transfusions and the clearance of immune complexes are important in these disorders, we investigated the effect of GM-CSF on the Fc gamma receptors largely responsible for this immune clearance. Human monocytes were cultured in buffer or 100 U/mL of recombinant GM-CSF (rGM-CSF) for 48 hours. Flow cytometry was used to evaluate changes in the expression of the three Fc gamma receptors. Fc gamma RII was the only Fc gamma receptor significantly increased by rGM-CSF. This increase in Fc gamma RII surface protein was correlated with an increase in macrophage binding of erythrocytes sensitized with IgG. In addition, an increase in monocyte binding of IgG-sensitized RBCs was observed in RBCs sensitized with murine IgG2b antibody, which preferentially binds to Fc gamma RII. rGM-CSF also increased the monocyte Fc gamma RII-dependent low-affinity binding site for trimeric IgG. Furthermore, rGM-CSF was observed to increase the expression of monocyte Fc gamma RII mRNA, including that for Fc gamma RIIA. Thus, these studies demonstrate that GM-CSF increases monocyte Fc gamma RII expression and function and suggests that a similar process may be present in vivo. This effect may be either beneficial (increased clearance of immune complexes) and/or detrimental (increased transfusion requirements) in select patients.
OBJECTIVE: To prospectively study the clinical features, pathophysiology, treatment and prognosis of Wegener granulomatosis. DESIGN: Of the 180 patients with Wegener granulomatosis referred to the National Institute of Allergy and Infectious Diseases during the past 24 years, 158 have been followed for 6 months to 24 years (a total of 1229 patient-years). MEASUREMENTS: Characteristics of clinical presentation, surgical pathology, course of illness, laboratory and radiographic findings, and the results of medical and surgical treatment have been recorded in a computer-based information retrieval system. SETTING: The Warren Magnuson Clinical Center of the National Institutes of Health. MAIN RESULTS: Men and women were equally represented; 97% of patients were white, and 85% were more than 19 years of age. The mean period of follow-up was 8 years. One hundred and thirty-three patients (84%) received "standard" therapy with daily low-dose cyclophosphamide and glucocorticoids. Eight (5.0%) received only low-dose cyclophosphamide. Six (4.0%) never received cyclophosphamide and were treated with other cytotoxic agents and glucocorticoids. Ten patients (6.0%) were treated with only glucocorticoids. Ninety-one percent of patients experienced marked improvement, and 75% achieved complete remission. Fifty percent of remissions were associated with one or more relapses. Of 99 patients followed for greater than 5 years, 44% had remissions of greater than 5 years duration. Thirteen percent of patients died of Wegener granulomatosis, treatment-related causes, or both. Almost all patients had serious morbidity from irreversible features of their disease (86%) or side effects of treatment (42%). CONCLUSIONS: The course of Wegener granulomatosis has been dramatically improved by daily treatment with cyclophosphamide and glucocorticoids. Nonetheless, disease- and treatment-related morbidity is often profound. Alternative forms of therapy have not yet achieved the high rates of remission induction and successful maintenance that have been reported with daily cyclophosphamide treatment. Despite continued therapeutic success with cyclophosphamide, our long-term follow-up of patients with Wegener granulomatosis has led to increasing concerns about toxicity resulting from prolonged cyclophosphamide therapy and has encouraged investigation of other therapeutic regimens.
While it is known that mast cells arise from pluripotential hematopoietic cells and express their mature phenotypes in tissues, the sequence of events in maturation is incompletely understood. To study early mast cells, we sorted cells from interleukin-3 (IL-3)-dependent mouse bone marrow cultures on the basis of Fc epsilon RI and examined their morphology, histamine content, and growth characteristics. Flow cytometric analysis and sort showed that the Fc epsilon RI-bearing (Fc epsilon RI+) cells increased from 0% on day 0 to 90% by day 21 and that the total number of Fc epsilon RI+ cells increased from 0 at the start of culture to 3.75 x 10(5) cells by day 21 from an initial population of 1 x 10(5) cells. The dissociation rate of 125I-labeled IgE from early cultured cells resembled the dissociation rate of mouse IgE from mature murine mast cells. Mean fluorescence intensity increased over time, reflecting an increase in IgE receptor density. Fc epsilon RI+ cells were also positive for Fc gamma RII/III. Morphologic studies showed gradual acquisition of metachromatic granules in the Fc epsilon RI+ cells, which was paralleled by an increase in histamine content. Sorted Fc epsilon RI+ cells, when placed in liquid suspension culture, gave rise to pure mast cell populations. Fc epsilon RI+ cells sorted at day 3 and cultured in agarose with IL-3 gave rise to 4,800 small and 150 medium-size mast cell colony-forming units per 10(6) cells, while Fc epsilon RI- cells gave rise to 23 medium-size and 49 large mast cell colony-forming units per 10(6) cells. Fc epsilon RI+ cells grown in granulocyte-macrophage colony-stimulating factor (CSF) or macrophage-CSF did not give rise to colony-forming units. These results show that Fc epsilon RI+ cells have proliferative potential, but that there also is a population of mast cell progenitor cells that have not yet expressed Fc epsilon RI, and such individual progenitor cells have greater potential for proliferation than cells that express Fc epsilon RI.
Wegener's granulomatosis (WG) is a multisystem inflammatory disease characterized by vasculitis, granuloma formation, and necrosis. Among 158 patients treated at the National Institutes of Health during the past 24 years, 145 (92%) had an otolaryngologic manifestation of their disease and 25 (16%) had subglottic stenosis (SGS). SGS varied from asymptomatic to life-threatening. Sixteen (80%) of 20 patients with fixed SGS required surgical intervention, including manual dilations, carbon-dioxide laser resections, and laryngotracheoplasty (LTP). LTP was performed with and without microvascular reconstruction. Thirteen of the patients required tracheostomy and all 13 were ultimately decannulated. Five patients who repeatedly failed dilations and/or endoscopic laser surgery underwent LTP. Since 1987, two patients have undergone LTP with microvascular free flaps. Both patients were subsequently decannulated. The authors' experience demonstrates that management of SGS in WG is complex, requiring individualized frequent multimodality interventions to achieve satisfactory results. Microvascular laryngotracheal reconstruction should be considered in the surgical armamentarium for patients with persistent stenoses.
Local accumulation of endothelins (ETs) as cytokine-like factors via autocrine/paracrine mechanisms seems to represent an important aspect of their pathophysiological action. This assumption prompted us to investigate mast cells as a possible source of these peptides. With the use of a combination of high-performance liquid chromatography and a radioimmunoassay specific for endothelin-1 (ET-1), 3-week-old cultures of primary murine bone marrow mast cells (BMMC) as well as various mast cell lines were shown to contain and secrete immunoreactive ET-1. The amounts of this peptide were constitutively high in cellular extracts of BMMC, while there was considerable variation in the basal cellular content among mast cell lines, ranging from high (C57) to undetectable (RBL) levels. Treatment of the cells with the combination of phorbol myristate acetate (PMA) and A23187 for 5 h led to induction of ET-1 production in all cases tested. In contrast to the rapid stimulation by PMA/A23187 of histamine release from BMMC or C57 cells, however, no ET-1 secretory response was noted as early as 30 min after this combined treatment. Moreover, stimulation of mast cells with crosslinked IgE for 30 min or 5 h did not affect ET-1 secretion, suggesting that mast cell ET-1 release is not directly related to mast cell degranulation. After exposure of the cells to crosslinked IgE for 20 h, however, there was a distinct increase in immunoreactive ET-1 in the medium, to approximate 10 times the basal level. Polymerase chain reaction (PCR) analysis of mRNA expression in mast cells revealed that the amount of ET-1 PCR product, which is low or undetectable under nonstimulated conditions, is enhanceable by both PMA/A23187 and crosslinked IgE. The IgE-mediated induction kinetics for ET-1 mRNA parallel the kinetics obtained with PMA/A23187, albeit at somewhat lower levels. With the use of fluorescent ligand binding/flow cytometry as a screening method and a radioreceptor assay as the confirming method, mast cells were found to express a single class of high affinity ET receptors with distinct selectivity for ET-1 and a pharmacological profile resembling that of the ETA type ET receptor. Stimulation of mast cell ET-1 receptors did not provoke histamine release, nor did it result in a mitogenic response of BMMC. In conclusion, mast cells synthesize and secrete ET-1 and have ET receptors, suggesting that ET-1 may participate in mediating mast cell-related long-term changes in the microenvironment, e.g., in smooth muscle tone or the proliferation rate of fibroblasts.
Mast cells originate from pluripotential cells in the bone marrow. Specifically, human mast cells originate from CD 34-positive progenitor cells. Mast cell proliferation requires IL-3. In the mouse, additional mast cell growth is achieved by the addition of IL-4, and GM-CSF prevents mast cell proliferation. Early bone-marrow-derived mast cells can be identified by their IgE receptors, although they may not yet have the characteristic morphology of mature mast cells. Whether these early cells may by themselves have a physiologic role, remains to be determined. Mast cells persist in culture on fibroblast monolayers, in part due to the production of soluble factor(s) from the fibroblasts themselves. Final mast cell phenotype appears dependent upon the local tissue environment.
Congenital thrombocytopenia may occur in isolation or accompanied by eczema and immunodeficiency, as part of the X-linked hereditary Wiskott-Aldrich syndrome (WAS). Because the clinical and immunologic picture of WAS is variable, particularly early in life, definite diagnosis cannot always be made in cases with a negative family history. Two unrelated males with sporadic congenital thrombocytopenia had only questionable immunologic abnormalities as infants, making them clinically indistinguishable from cases of isolated thrombocytopenia, although one developed episodic neutropenia and the other began to manifest a multisystem autoimmune disease at 2 years of age. Evaluation of X chromosome inactivation in the T cells of both patients' mothers showed each of these women to have the same highly skewed X chromosome inactivation pattern seen in carriers of typical familial WAS. A T-cell defect was subsequently directly demonstrated in the second patient, whose lymphocytes failed to proliferate to periodate and anti-CD43. Taken together, these data suggest the presence of T cell immunodeficiency consistent with WAS in these patients. Furthermore, their mothers were found to have a very high likelihood of being carriers, lending support to the diagnosis of a hereditary disease in these boys and making possible genetic prediction in other family members and subsequent pregnancies.