FDG uptake by lymph nodes of HIV patients is inversely related to CD4 cell count: Indirect evidence in support of the homing theory of CD4 cells

Objectives To assess the relationship between FDG uptake by lymph nodes, the number of sites of lymph nodes involvement and CD4 cell count. An inverse relationship, if existing, between these variables would provide indirect support for the concept of homing induced apoptosis.

Methods Whole body 18-FDG PET scans were acquired prospectively on 16 patients suffering from HIV-1 on a Biograph PET-CT scanner. The intensity and extent of FDG uptake in lymph nodes of HIV patients under antiviral treatment were related to CD4 cell count and viral loads. Correlation analysis was performed using a non-parametric test and correction for multiple comparisons.

Results Predominant sites of lymph node involvement were the cervical and axillary region, followed by the inguinal region. CD4 cell count was inversely correlated to the average of the averaged SUV-mean values of involved lymph nodes as well as to the number of sites of lymph node involvement. Viral load was positively correlated to the average of the averaged SUV-mean values of involved lymph nodes and also to the number of sites of lymph nodes involved. An inverse correlation between CD4 cell count and viral load was identified.

Conclusions The inverse relationship between CD4 cell count and the average of the averaged SUV-mean values of involved lymph nodes and between CD4 cell count and the number of sites of lymph node involvement observed, indirectly supports the theory of CD4 cell depletion through forced lymph node homing.