'Naïve' and 'memory' CD4+ T-cells and T-cell receptor (TCR) V beta repertoire dynamics are independent of the levels of viremia following HIV seroconversion

The progression of 'naive' and 'memory' T-cells and the T-cell receptor Vbeta (TCR Vbeta) repertoire dynamics within the peripheral CD4+ T-cell compartment were studied in individuals following HIV seroconversion. Profound TCR Vbeta repertoire perturbations were observed within the CD4+ T-cell pool in treatment-naive patients regardless of their levels of viremia during the first 6-8 months after seroconversion. The ratio of 'naive' to 'memory' CD4+ T-cells as well as the TCR Vbeta repertoire dynamics did not appear to correlate with absolute numbers of CD4 T-cells.     

Antiretroviral drug resistance testing in adult HIV-1 infection: recommendations of an International AIDS Society-USA Panel

Martin S. Hirsch, MD; Françoise Brun-Vézinet, MD; Richard T. D'Aquila, MD; Scott M. Hammer, MD; Victoria A. Johnson, MD; Daniel R. Kuritzkes, MD; Clive Loveday, MD, PhD; John W. Mellors, MD; Bonaventura Clotet, MD, PhD; Brian Conway, MD; Lisa M. Demeter, MD; Stefano Vella, MD; Donna M. Jacobsen; Douglas D. Richman, MD

JAMA. 2000;283:2417-2426.

Objective  Assays for drug resistance testing in human immunodeficiency virus type 1 (HIV-1) infection are now available and clinical studies suggest that viral drug resistance is correlated with poor virologic response to new therapy. The International AIDS Society–USA sought to update prior recommendations to provide guidance for clinicians regarding indications for HIV-1 resistance testing.

Participants  An International AIDS Society–USA 13-member physician panel with expertise in basic science, clinical research, and patient care involving HIV resistance to antiretroviral drugs was reconvened to provide recommendations for the clinical use of drug resistance testing.

Evidence and Consensus Process  The full panel met regularly between January and October 1999. Resistance and resistance testing data appearing in the last decade through April 2000 and presentations at national and international research conferences were reviewed. Recommendations and considerations were developed by 100% group consensus, acknowledging that definitive data to support final recommendations are not yet available.

Conclusions  Emerging data indicate that despite limitations, resistance testing should be incorporated into patient management in some settings. Resistance testing is recommended to help guide the choice of new regimens after treatment failure and for guiding therapy for pregnant women. It should be considered in treatment-naive patients with established infection, but cannot be firmly recommended in this setting. Testing also should be considered prior to initiating therapy in patients with acute HIV infection, although therapy should not be delayed pending the results. Expert interpretation is recommended given the complexity of results and assay limitations.

     

The incidence and morphological features of pyramidal lobe on thyroid ultrasound

The aim of this article is to document the incidence and appearances of the pyramidal lobe of the thyroid gland, and discuss the clinical relevance of this entity in sonographic practice. A prospective study was undertaken over a period of 10 months. A total of 416 consecutive patients attending head and neck ultrasound lists were scanned by a single experienced radiologist or an advanced practitioner sonographer. At the time of reporting, the presence of a pyramidal lobe was recorded. The anatomical morphology was classified into five subgroups devised for the purposes of the study. Appearances were documented in both normal and pathological glands. Of the total number of patients scanned, 90 patients were found to have pyramidal lobes, giving an overall incidence of 21%. In all, 51% were found to originate from the right of the isthmus, 46% from the left and 2% from the midline. One patient had two pyramidal lobes. A significant number of patients having routine neck ultrasounds have an incidental finding of a pyramidal lobe. Ultrasound is an effective modality for the demonstration and classification of the pyramidal lobe, as well as identification of pathology. It is important for radiologists to be aware of this normal variation, as it may be the site of primary or recurrent thyroid pathology. Radiologists should report it where relevant to ensure adequate surgical treatment of pathological glands.     

Questions to and answers from the International AIDS Society-USA Resistance Testing Guidelines Panel

In 1996 the International AIDS Society-USA convened an international panel of experts in HIV drug resistance and clinical management to develop guidelines for the clinical use and limitations of resistance testing. Since then the International AIDS Society-USA Resistance Testing Guidelines Panel has developed and regularly published its recommendations. The latest panel recommendations appear in the July 1 issue of Clinical Infectious Diseases. We periodically pose questions to the panel relating to clinical elements of resistance testing that have been collected from HIV practitioners across the nation. We are happy to feature the latest edition in this issue of Topics in HIV Medicine. It is our hope that addressing these issues will help guide your treatment strategy decisions regarding resistance testing.