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Biomedical subjects

Neil M Ampel

Publications and source records attributed to Neil M Ampel.

16 recordsLinked to original sources
PubMed2006

An archived lot of coccidioidin induces specific coccidioidal delayed-type hypersensitivity and correlates with in vitro assays of coccidioidal cellular immune response.

No test for assessing cellular immune response in coccidioidomycosis is currently available in the United States. In the present study, we tested 49 healthy subjects living in the coccidioidal endemic region with a 1:55.8 dilution of a single lot of coccidioidin archived since the 1970s. In this group, 23 evaluable subjects demonstrated >/=5 mm of induration at 24, 48 or 72 h, with a mean+/-SEM maximum induration of 18.4+/-4.0 mm. The induration results among 14 subjects reactive at 24 h were compared to those from 179 individuals in an historical cohort studied in the 1980s using a reference lot of coccidioidin. Results were within 5% and not significantly different (P=0.924). The maximum induration response of all evaluable subjects correlated significantly with the results of in vitro tests of coccidioidal cellular immunity using supernatant interferon-gamma concentration and CD69 expression on T cells (Spearman rank correlation coefficients 0.69 and 0.68, respectively; P<0.01 for both). These data suggest that archived coccidioidin retains its potency and specificity and that in vitro test of coccidioidal immunity may have utility in the measurement of coccidioidal cellular immunity.

Adolescent↗
PubMed2006

Fatigue in coccidioidomycosis. Quantification and correlation with clinical, immunological, and nutritional factors.

While described in the past, the frequency and degree of fatigue associated with symptomatic coccidioidomycosis has never been quantified. Using the Fatigue Severity Scale (FSS), severe fatigue (FSS score = 41) was found in 65% of cases of active coccidioidomycosis compared to 42% in cohort of control subjects with chronic medical diseases (P=0.024). Fatigue in patients with symptomatic coccidioidomycosis declined significantly over four months (P=0.023). Severe fatigue in patients with symptomatic coccidioidomycosis was significantly associated with low body mass index (BMI; P=0.024) but was not significantly associated with either serum leptin (r2=0.078, P=0.261) or serum TNF-alpha (r2=0.028, P=0.504) concentrations. Severe fatigue is a common condition among patients with active coccidioidomycosis and is associated with a declining BMI.

Adult↗
PubMed2006

Spherules derived from Coccidioides posadasii promote human dendritic cell maturation and activation.

Previous studies have shown that dendritic cells (DC) pulsed with T27K, an antigenic preparation derived from spherules (of Coccidioides posadasii), activate peripheral blood mononuclear cells (PBMC) from nonimmune subjects as well as from patients with disseminated coccidioidomycosis. In this study, we have assessed the interaction between human DC and C. posadasii spherules in order to better understand the initial response between Coccidioides and the human host. Whole autoclaved spherules induced lymphocyte transformation in PBMC obtained from immune but not from nonimmune donors. Immature DC (iDC) bound fluorescein isothiocyanate-labeled spherules in a time- and temperature-dependent manner. This binding was blocked by the addition of mannan, suggesting mannose receptor involvement in the DC-Coccidioides interaction. Binding was subsequently associated with ingestion and intracellular processing of spherules. Coculturing of spherules with iDC was associated with the development of mature DC that were morphologically, phenotypically, and functionally similar to those induced by tumor necrosis factor alpha and prostaglandin E2. Finally, spherules incubated with iDC induced activation of PBMC from nonimmune donors. These data indicate that human DC are capable of binding, internalizing, and presenting antigens from Coccidioides spherules and suggest that DC may play a critical early role in the formation of a cellular immune response in human coccidioidomycosis.

Cell Adhesion↗
PubMed2006

Coccidioidomycosis as a common cause of community-acquired pneumonia.

The early manifestations of coccidioidomycosis (valley fever) are similar to those of other causes of community-acquired pneumonia (CAP). Without specific etiologic testing, the true frequency of valley fever may be underestimated by public health statistics. Therefore, we conducted a prospective observational study of adults with recent onset of a lower respiratory tract syndrome. Valley fever was serologically confirmed in 16 (29%) of 55 persons (95% confidence interval 16%-44%). Antimicrobial medications were used in 81% of persons with valley fever. Symptomatic differences at the time of enrollment had insufficient predictive value for valley fever to guide clinicians without specific laboratory tests. Thus, valley fever is a common cause of CAP after exposure in a disease-endemic region. If CAP develops in persons who travel or reside in Coccidioides-endemic regions, diagnostic evaluation should routinely include laboratory evaluation for this organism.

Adult↗
PubMed2005

Coccidioidomycosis.

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Coccidioidomycosis↗
PubMed2005

Coccidioidomycosis in persons infected with HIV type 1.

Coccidioidomycosis is a recognized opportunistic infection among persons infected with human immunodeficiency virus (HIV). Early in the HIV epidemic, most cases presented as overwhelming diffuse pulmonary disease with a high mortality rate. Although these cases are still seen, patients without significant immunodeficiency frequently present with a community-acquired pneumonia syndrome. Diagnosis can be established by cytological staining, culture, or serologic testing. All patients with HIV infection and symptomatic coccidioidomycosis should be treated with antifungal therapy. Severe cases frequently require a combination of therapy with amphotericin B and a triazole antifungal. Therapy for at least 1 year is recommended, but for patients with a focal pulmonary infection and peripheral blood CD4 lymphocyte counts of >250 cells/microL, it may be reasonable to stop therapy after this time. Other manifestations of coccidioidomycosis require prolonged therapy, and life-long treatment is recommended for persons with meningitis.

Antifungal Agents↗
PubMed2005

Preliminary evaluation of whole-blood gamma interferon release for clinical assessment of cellular immunity in patients with active coccidioidomycosis.

Assessment of the cellular immune response in coccidioidomycosis has epidemiologic and prognostic importance. Measurement of delayed-type hypersensitivity to skin testing has been used in the past to determine cellular immunity in coccidioidomycosis. However, no skin tests are currently available in the United States. Assay of gamma interferon (IFN-gamma) release in whole blood in response to incubation with antigen has been used to assess cellular immunity in tuberculosis. We used a similar assay using the coccidioidal antigen preparation T27K to measure the in vitro cellular immune responses among a cohort of 69 subjects with active coccidioidomycosis. IFN-gamma release was bimodal, with concentrations above and below 5 IU/ml. Using multivariate logistic regression, underlying disease and disseminated or chronic pulmonary coccidioidomycosis was significantly associated with the release of IFN-gamma at a concentration of <5 IU/ml (P = 0.02 or 0.05, respectively). In addition, the release IFN-gamma concentration was <5 IU/ml in all subjects with a clinical severity score of > or =6 (P = 0.02). The release IFN-gamma concentration correlated with expression of CD69 on T lymphocytes in an in vitro assay using T27K as the antigen (Spearman's rho = 0.59; P < 0.01). These results suggest that the IFN-gamma release assay with T27K as the antigen may be a useful clinical test for assessing cellular immunity in patients with active coccidioidomycosis.

Antigens, CD↗
PubMed2005

The mannose receptor mediates the cellular immune response in human coccidioidomycosis.

Mannose is the predominant monosaccharide in the coccidioidal antigen preparation T27K. Mannan and anti-CD206 antibody significantly decreased the surface expression of mannose receptor (MR) on adherent peripheral blood mononuclear cells and reduced the interleukin-2 (IL-2) release induced by T27K. These data suggest that MR mediates IL-2 release by T27K.

Antigens, Fungal↗
PubMed2005

Cellular immune suppressor activity resides in lymphocyte cell clusters adjacent to granulomata in human coccidioidomycosis.

The in situ immunologic response in human coccidioidomycosis remains undefined. To explore this further, pulmonary necrotizing coccidioidal granulomata were examined using immunohistochemical staining for lymphocyte subsets and for the cytokines interleukin-10 (IL-10) and gamma interferon (IFN-gamma). Discrete perigranulomatous lymphocytic clusters were seen in eight of nine tissues examined. In these tissues, T lymphocytes (CD3+) significantly outnumbered B lymphocytes (CD20+) in the mantle area of the granulomata (P = 0.028), whereas the clusters were composed of roughly equal numbers of T and B lymphocytes. While the number of cells in the mantle expressing IL-10 was similar to those in the perigranulomatous clusters, there were significantly more cells expressing IFN-gamma in the mantle than in the clusters (P = 0.037). Confocal microscopy revealed that CD4+ T lymphocytes and B lymphocytes are associated with IL-10 production. CD4+CD25+ T lymphocytes were identified in the perigranulomatous clusters but were not associated with IL-10 production. This is the first report noting perigranulomatous lymphocyte clusters and IL-10 in association with human coccidioidal granulomata and suggests that down-regulation of the cellular immune response is occurring within coccidioidal granulomata.

Coccidioidomycosis↗
PubMed2004

Increased risk of coccidioidomycosis in patients treated with tumor necrosis factor alpha antagonists.

OBJECTIVE: To describe a group of patients who were treated with tumor necrosis factor alpha (TNF alpha) antagonists and who developed coccidioidomycosis, and to test the hypothesis that patients with inflammatory arthritis receiving TNF alpha antagonist therapy are at higher risk for developing symptomatic coccidioidomycosis. METHODS: Cases of coccidioidomycosis were identified and reviewed from among patients receiving TNF alpha antagonist therapy from May 1998 through February 2003 in 5 practices within the areas endemic for coccidioidomycosis (Arizona, California, and Nevada). In addition, the relative risk of developing symptomatic coccidioidomycosis was calculated in patients with inflammatory arthritis who were receiving treatment with infliximab, in comparison with patients with inflammatory arthritis who were not receiving infliximab, from January 2000 to February 2003 in a single medical center. RESULTS: Thirteen cases of documented coccidioidomycosis were associated with TNF alpha antagonist therapy. Twelve cases were associated with the use of infliximab and 1 case with etanercept. Among the cohort of patients from a single medical center, 7 of the 247 patients receiving infliximab and 4 of the 738 patients receiving other therapies developed symptomatic coccidioidomycosis (relative risk 5.23, 95% confidence interval 1.54-17.71; P < 0.01). CONCLUSION: Patients with inflammatory arthritis who are undergoing treatment with infliximab appear to be at higher risk for developing symptomatic coccidioidomycosis as compared with those not receiving infliximab.

Acute Disease↗
PubMed2004

Combating opportunistic infections: coccidioidomycosis.

Coccidioidomycosis is a growing problem in the southwestern US. Although most cases of symptomatic coccidioidomycosis occur in healthy individuals, individuals with depressed cellular immunity are at particular risk. These include individuals with HIV infection, those who have undergone allogeneic transplantation and others on immunosuppressive medications. Most instances of primary pulmonary coccidioidomycosis do not require antifungal therapy. However, almost all cases of disseminated coccidioidomycosis will require such therapy. The triazole antifungals, fluconazole and itraconazole, are effective therapies for coccidioidomycosis. Amphotericin B is now reserved for severe or recalcitrant cases. Coccidioidal meningitis requires lifelong therapy with triazole antifungals. Intrathecal amphotericin B is required for those cases that fail. Prevention of coccidioidomycosis by environmental control is difficult. In the future, immunisation or immune modulation may offer protection.

Antifungal Agents↗
PubMed2003

In vitro modulation of cytokine production by lymphocytes in human coccidioidomycosis.

The modulation of the cytokine response to coccidioidal antigen by lymphocytes from donors with coccidioidomycosis was examined. In initial experiments, samples from 13 healthy immune donors and seven donors with active coccidioidomycosis anergic to the coccidioidal antigen T27K were assessed for CD3 lymphocyte expression of intracellular IFN-gamma using whole blood analysis. Addition of 10 ng/ml of recombinant IL-12 significantly increased response to T27K among immune and anergic subjects (p<0.05), but the percent of cells expressing IFN-gamma was still significantly greater for immune subjects. Among immune donors, the percentage of CD3 lymphocytes expressing IFN-gamma was significantly reduced with the addition of 10 ng/ml of recombinant IL-4, IL-10, TGF-beta, or their combination (for all, p<0.05). Among anergic donors, addition of 10 ng/ml of anti-IL-10 significantly increased IFN-gamma production (p<0.05), but addition of anti-IL-4 or anti-TGF-beta did not. Among immune donors, the percent of both CD3 lymphocytes and NK cells expressing IFN-gamma after 24h of T27K was increased above control (p<0.05), while the percent of NK cells producing TNF-alpha in response to T27K was not greater than control. Depletion of NK cells from peripheral blood mononuclear cells resulted in significant increases in TNF-alpha and IL-10 (for both, p<0.05) but resulted in no significant decrease in IFN-gamma or IL-2. These data demonstrate a differential response to stimulation with the coccidioidal antigen T27K among donors with coccidioidomycosis that can be manipulated by cell type and cytokine environment.

Antigens, Protozoan↗
PubMed2003

Measurement of cellular immunity in human coccidioidomycosis.

Measurement of cellular immune response in human coccidioidomycosis, a disease of the Western Hemisphere caused by the soil-dwelling fungus Coccidioides, began more than 75 years ago. Numerous studies have shown that measurement of coccidioidal cellular immunity is a useful epidemiologic and clinical tool. The first widely used coccidioidal skin-test reagent, coccidioidin, was derived from a filtrate of cultured mycelia of Coccidioides by Smith and colleagues in the 1940's. It remained the standard until the 1970's, when spherulin, obtained from the spherule form of the fungus, was found to be more sensitive. Both reagents are specific indicators of coccidioidal cellular immunity. Since then, other coccidioidal antigens have been identified and in vitro tests of cellular immunity have been shown to yield comparable results to skin testing. In vitro assays have also begun to open a window on the specific immunologic events of coccidioidal cellular immunity. Persistent expression of coccidioidal cellular immune response appears to augur an improved clinical outcome. Despite this, a study of a coccidioidal vaccine failed to demonstrate efficacy. Current and future studies are focused on modulating the coccidioidal immune response in vitro and in vivo and on developing an improved vaccine.

Coccidioides↗
PubMed2002

Reversal of coccidioidal anergy in vitro by dendritic cells from patients with disseminated coccidioidomycosis.

Coccidioides immitis is a pathogenic, dimorphic fungus found in the southwestern United States and is the causative agent of coccidioidomycosis. Extrathoracic dissemination of coccidioidomycosis is associated with a lack of cellular immunity. Dendritic cells (DCs) have been shown to initiate and modulate cellular immune responses. To determine whether DCs could modulate or initiate the immune response in this disease, monocyte-derived DCs were generated from coccidioidal Ag nonresponsive patients with disseminated coccidioidomycosis and healthy nonimmune individuals. DCs generated from both groups demonstrated phenotypes characteristic of DCs and stimulated strong allogeneic MLR. DCs from patients and healthy nonimmune individuals pulsed with the coccidioidal Ag preparation T27K induced lymphocyte proliferation. Mature DCs were much more efficient than immature DCs in these stimulations. Furthermore, restimulation of T27K-primed PBMC with Ag-pulsed DCs generated a C. immitis-specific cellular immune response in PBMC from patients with disseminated coccidioidomycosis as well as healthy nonimmune individuals. These results show that 1) DCs have the capacity to stimulate specific cellular immune responses from patients with disseminated coccidioidomycosis who are nonresponsive to coccidioidal Ag and healthy nonimmune individuals in vitro; 2) DCs can be used to screen coccidioidal Ags as candidates for human vaccine development; and 3) DC therapy may be useful in the treatment of disseminated coccidioidomycosis.

Antigens, Fungal↗
PubMed2002

In vitro whole-blood analysis of cellular immunity in patients with active coccidioidomycosis by using the antigen preparation T27K.

Measurement of cellular immunity in human coccidioidomycosis has important diagnostic and prognostic implications. The coccidioidin skin test has been the standard for the measurement of this, but it is not available in the United States. We examined the utility of measuring surface expression of CD69 on T lymphocytes in whole blood incubated with the coccidioidal antigen preparation T27K as an alternative to the skin test. Seventy donors with active coccidioidomycosis were studied. The mean fluorescent intensity (MFI) of CD69 expression on CD3 lymphocytes in response to T27K was 28.61 +/- 1.77, significantly greater than the control response of 11.45 +/- 0.78 (P < 0.001). The MFI CD69 response to T27K above that for the control (MFI CD69 above control) was 6.35 +/- 2.18 for seven subjects with disseminated coccidioidomycosis who were studied within 5 months of diagnosis. This was significantly below the value of 20.17 +/- 3.17 for 18 subjects with pulmonary coccidioidomycosis studied within 5 months of diagnosis and the value of 19.58 +/- 2.91 for 27 subjects with disseminated coccidioidomycosis studied after 5 months of diagnosis (for both, P < 0.05). There was an inverse correlation between coccidioidal clinical score and MFI CD69 above control for all 34 subjects with disseminated coccidioidomycosis (r = 0.362; P = 0.036) but not for the 36 subjects with pulmonary disease (r < 0.001; P = 0.993). Among 30 subjects for whom data were available, there was a highly significant association between the MFI CD69 above control and the supernatant concentrations of gamma interferon, interleukin-2 (IL-2), and tumor necrosis factor alpha (for all, P < 0.001), but not for IL-4, IL-5, or IL-10. These data indicate that in vitro assessment of CD69 expression on T lymphocytes by using T27K may be a useful measure of cellular immune response among subjects with active coccidioidomycosis.

Adult↗