A Pilot Study of the Discontinuation of Antifungal Therapy for Disseminated Cryptococcal Disease in Patients with Acquired Immunodeficiency Syndrome, following Immunologic Response to Antiretroviral Therapy

1179 CONCISE COMMUNICATION A Pilot Study of the Discontinuation of Antifungal Therapy for Disseminated Cryptococcal Disease in Patients with Acquired Immunodeficiency Syndrome, following Immunologic Response to Antiretroviral Therapy Judith A. Aberg,1,4,a Richard W. Price,2,4 Dorie M. Heeren,1,4,a and Barry Bredt3,4 Departments of 1Medicine and 2Neurology and 3General Clinical Research Center, University of California, San Francisco, and 4San Francisco General Hospital, San Francisco Cryptococcosis is the most common life-threatening form of meningitis associated with AIDS. Before the introduction of potent antiretroviral therapy, 5%–8% of patients with AIDS developed cryptococcal infection [1–3]. More than three-fourths of these cases developed when the patients’ CD4þ T cell counts fell below 50 cells/mL [4]. A significant decrease in mortality and relapse rate, compared with historical controls, was observed in the National Institute of Allergy and Infectious Diseases Mycoses Study Group (MSG) and AIDS Clinical Trials Group trial, which used amphotericin B (0.7 mg/kg/day) with or without flucytosine for the first 2 weeks, followed by 8 weeks of consolidation therapy with fluconazole or itraconazole [5]. Patients with AIDS must continue to receive long-term suppressive therapy Received 1 October 2001; revised 29 November 2001; electronically published 1 April 2002. Presented in part: 7th Conference on Retroviruses and Opportunistic Infections, San Francisco, January 2000 (abstract 250). Written informed consent was obtained from all patients or their parents or guardians. The human experimentation guidelines of the US Department of Health and Human Services and/or those of the authors’ institution were followed in the conduct of the clinical research. The study protocol was approved by the University of California, San Francisco, Committee on Human Research. Financial support: National Institutes of Health and University of California, San Francisco, Center for AIDS Research (grant P30 A127763). a Present affiliations: AIDS Clinical Trials Unit, Washington University School of Medicine, St. Louis, Missouri (J.A.A.); San Juan County Health and Community Services, Friday Harbor, Washington (D.M.H.). Reprints or correspondence: Dr. Judith A. Aberg, Washington University School of Medicine, AIDS Clinical Trials Unit, 4511 Forest Park Ave., Ste. 304, St. Louis, MO 63108 (). The Journal of Infectious Diseases 2002;185:1179–82 q 2002 by the Infectious Diseases Society of America. All rights reserved. 0022-1899/2002/18508-0024$02.00 for their lifetime unless cryptococcosis can be suppressed or possibly eradicated in the setting of antifungal therapy combined with potent antiretroviral therapy. Patients who have had immune restoration with antiretroviral therapy may be capable of eradicating this infection. Treatment of patients with cryptococcal meningitis in the absence of human immunodeficiency virus (HIV) infection includes a total of 6 weeks without subsequent continuation of maintenance therapy. Several case studies have been published reporting the successful discontinuation of cytomegalovirus (CMV) and Mycobacterium avium complex (MAC) maintenance therapy [6– 8]. On the basis of experience with other opportunistic infections, it is reasonable to hypothesize that, if cryptococcal-specific immunity could be restored in patients with a prior history of cryptococcosis, a 12-month course of antifungal therapy would be curative. Our primary objectives were to determine whether anticryptococcal therapy can be withdrawn from subjects who have received 12 months of fluconazole therapy, are asymptomatic with respect to cryptococcosis for > 16 weeks, have peripheral blood CD4þ T cell counts > 150 cells/mL, and have been receiving combination antiretroviral therapy for 16 weeks and to estimate the duration of time these subjects remain free of cryptococcal infection. Our secondary objectives were to determine whether the lymphoproliferative responses and cytokine responses predict risk of recurrent cryptococcal disease, by comparing various immunologic and virologic parameters in subjects who are withdrawn from anticryptococcal therapy and remain free of cryptococcal infection and in subjects who are withdrawn from anticryptococcal therapy and have recurrence of cryptococcal infection. To determine whether microbiologic cure of acquired immunodeficiency syndrome (AIDS)– related disseminated cryptococcosis is possible in patients receiving highly active antiretroviral therapy (HAART), antifungal therapy was discontinued in 6 patients with a history of disseminated cryptococcosis who had received > 12 months of antifungal therapy. All were asymptomatic and had absolute CD4þ T cell counts of . 150 cells/mL (range, 178– 525 cells/mL). Blood, cerebrospinal fluid (CSF), and urine samples were obtained for fungal culture. Serum and CSF cryptococcal antigen titers were also obtained. All 6 patients had CSF and blood cultures negative for Cryptococcus neoformans and were receiving HAART. All patients’ subsequent cultures remained sterile, and all patients were clinically asymptomatic 24 months after ending antifungal therapy. Disseminated cryptococcal disease can be cured by prolonged antifungal therapy in some patients with AIDS who experience sustained CD4 lymphocyte increases while receiving HAART. 1180 Aberg et al. Methods was permeabilized for 10 min at room temperature with 0.5 mL of Becton Dickinson FACS Permeabilizing Solution. Each sample was washed again and then was stained (5 mL anti– CD69-PE, 10 mL anti–tumor necrosis factor (TNF)–FITC, and 10 mL anti–CD4PECy5) for 30 min in the dark at room temperature, washed, fixed with 800 mL of 1% paraformaldehyde, and analyzed on a Coulter EPICS XL flow cytometer with System II acquisition and analysis software. In addition to the tissue culture medium used as a negative control, antigens included 10 mg/mL Staphylococcus enterotoxin B (SEB, Sigma), which served as a superantigen positive control, 3 mg/mL purified CMV lysate (Advanced Biotechnologies), and 20 mg/mL C. neoformans filtrate (CNEF; prepared for lymphoproliferation assays and kindly supplied by J. Murphy and S. Levitz, Boston Medical Center). Although it would have been ideal to include patients with cryptococcal meningitis but not AIDS as positive control subjects for the CNEF antigen, none were available to us during the period of the study. Results All 6 patients had blood and CSF cultures negative for C. neoformans and then discontinued fluconazole therapy. Follow-up urine, blood, and CSF cultures obtained 4 weeks after discontinuing fluconazole therapy were also negative for C. neoformans. All but 1 patient had negative CSF CRAG and sCRAG titers during the study period. The sCRAG titer progressively decreased in patient 6 and became negative at month 12. This patient’s CSF CRAG titer was initially 1:2 and was not repeated. All patients remained asymptomati (...truncated)