0

The full content of Annals is available to subscribers

Subscribe/Learn More  >
Articles |

Histoplasmosis Relapse in Patients with AIDS: Detection Using Histoplasma capsulatum variety capsulatum Antigen Levels

L. Joseph Wheat, MD; Patricia Connolly-Stringfield, BS; Robinette Blair, BS; Kathleen Connolly, BS; Todd Garringer, BS; and Barry P. Katz, PhD
[+] Article and Author Information

Grant Support: In part by the Department of Veterans Affairs and the AIDS program of the National Institutes of Allergy and Infectious Diseases.

Requests for Reprints: L. Joseph Wheat, MD, OPW430, Wishard Memorial Hospital, 1001 West Tenth Street, Indianapolis, IN 46202-2879.

Current Author Addresses: Drs. Wheat and Katz, Ms. Connolly-Stringfield, Ms. Blair, Ms. Connolly, and Mr. Garringer: Department of Internal Medicine, Indiana University, 1100 West Michigan Street, Indianapolis, IN 46202.


Ann Intern Med. 1991;115(12):936-941. doi:10.7326/0003-4819-115-12-936
Text Size: A A A

Objective: To assess the accuracy of Histoplasma capsulatum variety capsulatum polysaccharide antigen testing for the identification of histoplasmosis relapse in patients with the acquired immunodeficiency syndrome (AIDS).

Design: A retrospective study using stored specimens.

Setting: A referral center and several private hospitals.

Patients: Twenty episodes of histoplasmosis relapse were evaluated in 17 patients with AIDS from November 1987 to August 1990. Controls included 30 patients with AIDS and histoplasmosis who did not have a relapse during maintenance therapy and who were initially tested during the same week as the patients with relapse. A second control group included seven patients with AIDS and histoplasmosis who were evaluated for relapse on 23 occasions; relapse, however, was excluded on each occasion.

Measurements: To avoid interassay variability, specimens were tested for H.c. var. capsulatum polysaccharide antigen with the same radioimmunoassay.

Main Outcome Measure: The change in the H.c. var. capsulatum polysaccharide antigen level during successful as opposed to unsuccessful maintenance therapy for the prevention of histoplasmosis relapse.

Main Results: For the 20 episodes of relapse (17 patients), H.c. var. capsulatum antigen levels increased by at least 2 radioimmunoassay units in 12 of 14 serum specimens tested (85.7%; 95% Cl, 57.2% to 98.2%) and in 17 of 18 urine specimens tested (94.4%; Cl, 72.7% to 99.9%). Antigen levels increased in the urine or serum in 1 of 83 specimens (1.2%; Cl, 0.03% to 6.6%) obtained on 56 occasions (1.8%; Cl, 0.04% to 9.6%) from controls (specificity, 98.2%; Cl, 90.4% to 99.96%). In three cases of relapse, antigen levels increased before clinical relapse was suspected. Complement fixation titers increased by at least 2 dilutions in 4 of 11 cases (36.4%; Cl, 10.9% to 69.2%) but in 0 of 9 control patients (Cl, 0% to 28.3%).

Conclusion: An increase in H.c. var. capsulatum polysaccharide antigen levels of 2 units or more strongly suggests histoplasmosis relapse. The presence of increasing titers of anti-H.c. var. capsulatum antibodies by complement fixation is less accurate for the diagnosis of relapse.

Figures

Tables

References

Letters

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Comments

Submit a Comment
Submit a Comment

Summary for Patients

Clinical Slide Sets

Terms of Use

The In the Clinic® slide sets are owned and copyrighted by the American College of Physicians (ACP). All text, graphics, trademarks, and other intellectual property incorporated into the slide sets remain the sole and exclusive property of the ACP. The slide sets may be used only by the person who downloads or purchases them and only for the purpose of presenting them during not-for-profit educational activities. Users may incorporate the entire slide set or selected individual slides into their own teaching presentations but may not alter the content of the slides in any way or remove the ACP copyright notice. Users may make print copies for use as hand-outs for the audience the user is personally addressing but may not otherwise reproduce or distribute the slides by any means or media, including but not limited to sending them as e-mail attachments, posting them on Internet or Intranet sites, publishing them in meeting proceedings, or making them available for sale or distribution in any unauthorized form, without the express written permission of the ACP. Unauthorized use of the In the Clinic slide sets will constitute copyright infringement.

Toolkit

Buy Now

to gain full access to the content and tools.

Want to Subscribe?

Learn more about subscription options

Advertisement
Related Articles
Topic Collections
PubMed Articles
Forgot your password?
Enter your username and email address. We'll send you a reminder to the email address on record.
(Required)
(Required)