# Correlation Between Radiological Features of Axillary Lymph Nodes with CD4 Count and Plasma Viral Load in Patients with HIV

## TL;DR

This study found that higher axillary lymph node density on CT scans is linked to lower immune function and higher HIV viral load, suggesting a potential imaging biomarker for HIV.

## Contribution

The study introduces axillary lymph node density as a novel non-invasive imaging biomarker for immune suppression and high viral load in HIV patients.

## Key findings

- Lymph node density increases with lower CD4 counts and higher viral loads in HIV patients.
- A density threshold of 84.5 HU can distinguish impaired from preserved immune function with moderate sensitivity and specificity.

## Abstract

In radiological practice, axillary lymph nodes in individuals living with HIV often display structural alterations, yet the relevance of these findings to immune status is not clearly defined. This study investigated whether CT-based characteristics of these lymph nodes reflect laboratory markers of immunosuppression, including CD4 count and viral load. Our results showed that lymph node density increases in patients with lower CD4 levels and higher viral load. These observations indicate that routine CT assessment may provide additional insight into immune function and help guide future research on imaging biomarkers in HIV infection.

Objective: Axillary lymph node changes are frequently observed in patients with HIV, yet their radiological characteristics and clinical significance remain underexplored. This study aimed to evaluate the association between axillary lymph node computed tomography (CT) features and clinical markers of immune function, including CD4 lymphocyte count and plasma viral load, in HIV-positive patients. Materials and Methods: In this retrospective study, 113 HIV-positive patients who underwent contrast-enhanced chest CT were included. Patients were stratified by CD4 count (<200, 200–500, >500 cells/μL) and plasma viral load (<100,000 or >100,000 copies/mL). Axillary lymph node parameters—including maximum and minimum diameters, cortical thickness, hilar width, and density (Hounsfield units, HU)—were measured on multiplanar reconstructed CT images. Group differences were assessed using the Kruskal–Wallis and Mann–Whitney U tests, and Spearman’s correlation was used to evaluate associations between imaging and laboratory findings. Receiver operating characteristic (ROC) curve analysis identified optimal density thresholds. Results: Lymph node diameters, cortical thickness, and hilar width did not significantly differ between CD4 groups. However, mean lymph node density was higher in patients with CD4 < 200 cells/μL (p = 0.024). A density threshold of 84.5 HU distinguished impaired from preserved immune function (sensitivity 61.1%, specificity 71.2%). Patients with viral load >100,000 copies/mL showed increased lymph node density, minimal diameter, and cortical thickness. Conclusions: Elevated axillary lymph node density correlates with immune suppression and high viral load, suggesting its potential as a non-invasive prognostic imaging biomarker in HIV infection.