Derek J. Bays

Early Treatment With Fluconazole May Abrogate the Development of IgG Antibodies in Coccidioidomycosis

BACKGROUND We have observed a number of patients who fail to develop coccidioidal complement fixing (CF) antibody (immunoglobulin [IgG]) after the initiation of early antifungal therapy. Although this is the first description of this phenomenon in mycology, a precedent for the abrogation of the immune response has been observed in other conditions, including primary syphilis and primary Lyme disease. METHODS We conducted a retrospective case-control study to determine any patient-specific risk factors associated with this observation. Additionally, in vitro analysis of the coccidioidal CF (IgG) antigen (Cts1) was performed after Coccidioides was grown under escalating fluconazole concentrations. RESULTS Seventeen patients persistently positive for coccidioidal IgM antibodies without developing an IgG response (cases) were compared with 64 consecutive patients who did develop coccidioidal CF (IgG) antibodies (controls). Early treatment with antifungals (within 2 weeks of symptom onset) was associated with an abrogation of IgG antibody production (P < .001). With immunodiffusion testing, control serum demonstrated a lack of IgG seroreactivity when Coccidioides posadasii grown in the presence of escalating fluconazole doses (0.5-128 μg/mL) was used as the antigen; however, control serum remained seroreactive for the presence of IgM. The coccidioidal IgG antigen (Cts1) was shown to be diminished when cultures were grown in the presence of fluconazole, lending further in vitro plausibility to our findings. CONCLUSIONS The abrogation of an IgG response in patients treated early in the course of coccidioidal infection may complicate serodiagnosis and epidemiologic studies, and further study to determine the potential clinical implications should be performed.

Phenotypic Differences of Cryptococcus Molecular Types and Their Implications for Virulence in a Drosophila Model of Infection

ABSTRACT Compared to Cryptococcus neoformans, little is known about the virulence of the molecular types in Cryptococcus gattii. We compared in vitro virulence factor production and survival data using a Drosophila model of infection to further characterize the phenotypic features of different cryptococcal molecular types. Forty-nine different isolates were inoculated into wild-type flies and followed for survival. In vitro, isolates were assessed for growth at 30 and 37°C, melanin production, capsule size, resistance to H2O2, and antifungal susceptibility. A mediator model was used to assess molecular type and virulence characteristics as predictors of survival in the fly model. VGIII was the most virulent molecular type in flies (P < 0.001). At 30°C, VGIII isolates grew most rapidly; at 37°C, VNI isolates grew best. C. gattii capsules were larger than those of C. neoformans (P < 0.001). Mediator model analysis found a strong correlation of Drosophila survival with molecular type and with growth at 30°C. We found molecular-type-specific differences in C. gattii in growth at different temperatures, melanin production, capsule size, ability to resist hydrogen peroxide, and antifungal susceptibility, while growth at 30°C and the VGIII molecular type were strongly associated with virulence in a Drosophila model of infection.

Coccidioidomycosis: Adenosine Deaminase Levels, Serologic Parameters, Culture Results, and Polymerase Chain Reaction Testing in Pleural Fluid

BACKGROUND In a patient with positive serum serology for coccidioidomycosis, the differential diagnosis of concurrent pleural effusions can be challenging. We, therefore, sought to clarify the performance characteristics of biochemical, serologic, and nucleic-acid-based testing in an attempt to avoid invasive procedures. The utility of adenosine deaminase (ADA), coccidioidal serology, and polymerase chain reaction (PCR) in the evaluation of pleuropulmonary coccidioidomycosis has not been previously reported. METHODS Forty consecutive patients evaluated for pleuropulmonary coccidioidomycosis were included. Demographic data, pleural fluid values, culture results, and clinical diagnoses were obtained from patient chart review. ADA testing was performed by ARUP Laboratories, coccidioidal serologic testing was performed by the University of California-Davis coccidioidomycosis serology laboratory, and PCR testing was performed by the Translational Genomics Research Institute using a previously published methodology. RESULTS Fifteen patients were diagnosed with pleuropulmonary coccidioidomycosis by European Organization for the Research and Treatment of Cancer/Mycoses Study Group criteria. Pleural fluid ADA concentrations were < 40 IU/L in all patients (range, < 1.0-28.6 IU/L; median, 4.7). The sensitivity and specificity of coccidioidal serologic testing was 100% in this study. The specificity of PCR testing was high (100%), although the overall sensitivity remained low, and was comparable to the experience of others in the clinical use of PCR for coccidioidal diagnostics. CONCLUSION Contrary to prior speculation, ADA levels in pleuropulmonary coccidioidomycosis were not elevated in this study. The sensitivity and specificity of coccidioidal serologic testing in nonserum samples remained high, but the clinical usefulness of PCR testing in pleural fluid was disappointing and was comparable to pleural fluid culture.

Original ResearchChest InfectionsCoccidioidomycosis: Adenosine Deaminase Levels, Serologic Parameters, Culture Results, and Polymerase Chain Reaction Testing in Pleural Fluid

BACKGROUND In a patient with positive serum serology for coccidioidomycosis, the differential diagnosis of concurrent pleural effusions can be challenging. We, therefore, sought to clarify the performance characteristics of biochemical, serologic, and nucleic-acid-based testing in an attempt to avoid invasive procedures. The utility of adenosine deaminase (ADA), coccidioidal serology, and polymerase chain reaction (PCR) in the evaluation of pleuropulmonary coccidioidomycosis has not been previously reported. METHODS Forty consecutive patients evaluated for pleuropulmonary coccidioidomycosis were included. Demographic data, pleural fluid values, culture results, and clinical diagnoses were obtained from patient chart review. ADA testing was performed by ARUP Laboratories, coccidioidal serologic testing was performed by the University of California-Davis coccidioidomycosis serology laboratory, and PCR testing was performed by the Translational Genomics Research Institute using a previously published methodology. RESULTS Fifteen patients were diagnosed with pleuropulmonary coccidioidomycosis by European Organization for the Research and Treatment of Cancer/Mycoses Study Group criteria. Pleural fluid ADA concentrations were < 40 IU/L in all patients (range, < 1.0-28.6 IU/L; median, 4.7). The sensitivity and specificity of coccidioidal serologic testing was 100% in this study. The specificity of PCR testing was high (100%), although the overall sensitivity remained low, and was comparable to the experience of others in the clinical use of PCR for coccidioidal diagnostics. CONCLUSION Contrary to prior speculation, ADA levels in pleuropulmonary coccidioidomycosis were not elevated in this study. The sensitivity and specificity of coccidioidal serologic testing in nonserum samples remained high, but the clinical usefulness of PCR testing in pleural fluid was disappointing and was comparable to pleural fluid culture.

Fluoride excess in coccidioidomycosis patients receiving long-term antifungal therapy: an assessment of currently available triazoles.

ABSTRACT The use of voriconazole, a trifluorinated antifungal, has been associated with the development of fluoride excess and periostitis/exostoses. We evaluated a cohort of patients on long-term triazole therapy and found that other fluorinated triazoles (fluconazole and posaconazole) conferred no risk for the development of hyperfluorosis and its complications in our cohort.

Serum (1→3)-β-D-Glucan Measurement in Coccidioidomycosis

ABSTRACT The serum (1→3)-β-d-glucan assay has emerged as an important diagnostic test for invasive fungal disease. The utility of this assay in coccidioidomycosis has not been previously studied. Using a cutoff value of ≥80 pg/ml, we found the sensitivity (43.9%), specificity (91.1%), positive predictive value (81.8%), and negative predictive value (64.1%) to be similar to those of the assay in diagnosing other invasive mycoses.

Association between serum 25-hydroxyvitamin D level and type of coccidioidal infection

The clinical manifestations of coccidioidomycosis vary depending upon the extent of exposure and immune status of the host. Recent studies have demonstrated an essential role for vitamin D in both innate and acquired immunity and serum levels strongly correlate with the development of upper respiratory tract infections, including tuberculosis. Despite similar pathophysiologic processes at play in the control of tuberculosis and invasive fungal infections, a possible association of low serum 25(OH) vitamin D levels had not previously been assessed in the latter patient group. Therefore, we performed a case-control study examining serum 25(OH) vitamin D levels in three distinct groups of patients with coccidioidomycosis as compared to healthy uninfected controls. Of the 89 patients included in this study, there were 26 negative controls, 23 who were immune, 22 with primary coccidioidal pneumonia, and 18 who had disseminated/meningeal infection. Serum 25(OH) vitamin D levels varied between groups with lowest levels seen in the group with disseminated/meningeal coccidioidomycosis (P= 0.14). In this evaluation of a diverse group of patients with varying forms of coccidioidomycosis we found no association of vitamin D with the acquisition or resolution of this infection. Vitamin D does not play a significant role in host susceptibility to coccidioidomycosis.

Favorable Outcome in Coccidioides Endophthalmitis - A Combined Medical and Surgical Treatment Approach

Purpose: To describe a case of Coccidioides endophthalmitis that resulted in a favorable visual outcome after a combined medical and surgical approach. Methods: A 33-year-old previously healthy woman was referred for evaluation of dyspnea and left-sided vision loss, which began 3 months before, after a trip to Nevada. She was found to have a pulmonary cavitary lesion and fluffy white material in the anterior chamber. An aqueous and vitreous paracentesis grew Coccidioides species. She was managed medically with a total of 7 weekly intravitreal injections of amphotericin B and intravenous liposomal amphotericin B followed by transition to oral posaconazole. Seven months after presentation, to ensure ocular sterilization and to clear the visual axis, she underwent temporary keratoprosthesis implantation, anterior segment reconstruction, removal of a cyclitic membrane and the crystalline lens, pars plana vitrectomy, placement of a pars plana Ahmed drainage device, and penetrating keratoplasty. Results: After surgical intervention and with maintenance posaconazole therapy, the patient had resolution of her dyspnea and improved uncorrected (aphakic) vision with a clear corneal graft, quiet anterior chamber, and normal optic nerve and retina. Conclusions: A combined medical and surgical approach resulted in a favorable visual outcome and avoided the need for enucleation.