Biopsies of lymph nodes in the groin, performed in the context of acute HIV infection, are safe and well tolerated, according to a Thai study published in the Journal of Acquired Immune Deficiency Syndromes. Many HIV cure studies depend on lymph node biopsies in people who have acute (very early) HIV infection.
The study assessed the safety and tolerability of lymph node biopsies in individuals with acute HIV infection. In the study, 78 biopsies (39 at baseline and 39 during the follow-up) were obtained from 67 participants (97% male).
Only ten (12.8%) adverse events were reported, of which six (7.7%) were of grade 1 (mild), and four (5.1%) of grade 2 (moderate). The reported adverse events were discomfort (pain or swelling) at the site of the biopsy in eight cases (10.2%) and haematoma – a local accumulation of clotted blood within the tissues – in two cases (2.6%).
Eight of the ten reported adverse events were associated with biopsies performed during acute infection; the remaining two were associated with biopsies performed in the following months. Adverse events occurred more frequently during acute than in later infection. Also, the rate of adverse events was higher in people with a detectable viral load (during acute infection, as well as at a later time before HIV treatment was fully effective) than in those with a suppressed viral load. However, none of these differences were statistically significant.
Neither age, CD4 cell count nor sexually transmitted infections were associated with incidence of adverse events. All biopsy-related adverse events were transient and self-limited. Finally, participants who underwent two (rather than one) lymph node biopsies did not increase their risk of adverse events.
Other facts from the study: in accordance with the protocol, the procedure was offered to people at their enrolment and different timepoints; a maximum of four biopsies per participant was allowed; each biopsy involved the removal of a single lymph node through a skin incision; repeated biopsies were performed on the side of the groin opposite to the previous biopsy.
The insight provided by this study is very important. During acute HIV infection, latent HIV reservoirs are rapidly established in the lymphoid tissues which, if sampled and examined at this specific moment of infection, can increase our understanding of HIV pathogenesis. But as acute infection is associated with intense viral replication and immune activation, it was so far unclear if a biopsy performed against this inflammatory background would cause harm to trial participants.
It’s worth pointing out that all 67 people were already participants in a larger study (RV254/SEARCH 010). It’s possible that such individuals may be better informed about medical procedures and more tolerant of side-effects than other people.
The RV254/SEARCH 010 study is an observational research project conducted at the Anonymous Clinic of the Thai Red Cross AIDS Research Centre in Bangkok. It aims to screen 30,000 HIV-positive people a year, in order to identify 40 to 50 people with acute HIV infection per year. They are then enrolled in a cohort where they will undergo many different exams, from neuropsychological evaluation to colon and lymph node biopsies, that will contribute to further documenting acute HIV infection.
Chintanaphol M et al. Brief Report: Safety and Tolerability of Inguinal Lymph Node Biopsy in Individuals With Acute HIV Infection in Thailand. Journal of Acquired Immune Deficiency Syndromes 79: 244-248, 2018. (Full text freely available).