Understanding viral blips in people with HIV on antiretroviral therapy: a nationwide Swedish cohort study of 4,210 individuals.
12 affiliations
- 1Department of Infectious Diseases, Sahlgrenska Academy, Institute of Biomedicine, University of Gothenburg, Gothenburg, SE-416 45, Sweden. [email protected].
- 2Department of Infectious Diseases, Region Västra Götaland, Sahlgrenska University Hospital, Gothenburg, Sweden. [email protected].
- 3Department of Laboratory Medicine, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
- 4Department of Medicine Huddinge, Division of Infectious Diseases, Karolinska Institutet, Stockholm, Sweden.
- 5Department of Infectious Diseases, Karolinska University Hospital, Stockholm, Sweden.
- 6Department of Infectious Diseases/Venhälsan, South General Hospital, Stockholm, Sweden.
- 7Department of Translational Medicine, Infectious Diseases Unit, Lund University, Malmö, Sweden.
- 8University of Linköping, Linköping, Sweden.
- 9Department of Infectious Diseases, Linköping University Hospital, Linköping, Sweden.
- 10Department of Medical Sciences, Section of Infectious Diseases, Uppsala University, Uppsala, Sweden.
- 11Department of Infectious Diseases, Sahlgrenska Academy, Institute of Biomedicine, University of Gothenburg, Gothenburg, SE-416 45, Sweden.
- 12Department of Infectious Diseases, Region Västra Götaland, Sahlgrenska University Hospital, Gothenburg, Sweden.
Abstract
Background
The pathogenesis and clinical consequences of viral blips are not completely understood. The aim of this large nationwide study was to investigate the incidence of viral blips and factors associated with them, with particular attention to the third (core) agent class-comparing integrase strand transfer inhibitor (INSTI)-based regimens with non-nucleoside reverse transcriptase inhibitor (NNRTI)- and protease inhibitor (PI)-based regimens.Methods
From the Swedish national InfCareHIV cohort, we included treatment-naïve adults who commenced antiretroviral therapy (ART) from 1 January 2007; data were extracted on 30 September 2020. Viral blips were defined as transient plasma HIV RNA levels between 50 and 500 copies/mL preceded and followed by HIV RNA < 50 copies/mL. Virological failure was defined as two consecutive HIV RNA samples > 200 copies/mL or a single sample of HIV RNA > 1,000 copies/mL, in previously suppressed individuals with more than 12 months since ART initiation. Cox regression was used for event analyses.Results
In total, 4,210 individuals were included, of whom 853 (20.3%) had 1-6 registered blips. Median observation time was 5.5 years (range 0.5-13.7). Blip incidence was 4.35 (95% CI 4.02-4.69) per 100 person-years. In a sensitivity analysis applying the narrower definition of 50-199 copies/mL, the incidence was 3.80 (95% CI 3.49-4.11) per 100 person-years. Individuals on INSTIs and NNRTIs had similar risk, while those on PIs had a significantly higher risk of blips (hazard ratio [HR] 1.22, 95% CI 1.03-1.45; p = 0.02). Transient viremia was not associated with an increased risk of subsequent virological failure; individuals with blips had a lower risk than those with continuously undetectable HIV RNA (HR 0.54, 95% CI 0.41-0.71; p < 0.0001).Conclusion
Individuals on INSTI- and NNRTI-based ART had fewer viral blips than those on PI-based ART. In this cohort, transient viremia below 500 HIV RNA copies/mL was not associated with a higher risk of subsequent virological failure.Clinical trial number
Not applicable.
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BibTeX
@article{sorstedt2026understanding,
title = {{Understanding viral blips in people with HIV on antiretroviral therapy: a nationwide Swedish cohort study of 4,210 individuals.}},
author = {Erik Sörstedt and Staffan Nilsson and Anders Sönnerborg and Christina Carlander and Carl Johan Treutiger and Fredrik Månsson and Lena Änghagen and Helena Berggren and Magnus Gisslén and Aylin Yilmaz},
journal = {BMC infectious diseases},
year = {2026},
month = oct,
doi = {10.1186/s12879-026-14654-z},
url = {https://europepmc.org/article/MED/42902278},
note = {CC BY},
}
RIS
TY - JOUR
TI - Understanding viral blips in people with HIV on antiretroviral therapy: a nationwide Swedish cohort study of 4,210 individuals.
AU - Erik Sörstedt
AU - Staffan Nilsson
AU - Anders Sönnerborg
AU - Christina Carlander
AU - Carl Johan Treutiger
AU - Fredrik Månsson
AU - Lena Änghagen
AU - Helena Berggren
AU - Magnus Gisslén
AU - Aylin Yilmaz
PY - 2026
DA - 2026/10/16
JO - BMC infectious diseases
DO - 10.1186/s12879-026-14654-z
UR - https://europepmc.org/article/MED/42902278
AB - Background The pathogenesis and clinical consequences of viral blips are not completely understood. The aim of this large nationwide study was to investigate the incidence of viral blips and factors associated with them, with particular attention to the third (core) agent class-comparing integrase strand transfer inhibitor (INSTI)-based regimens with non-nucleoside reverse transcriptase inhibitor (NNRTI)- and protease inhibitor (PI)-based regimens.Methods From the Swedish national InfCareHIV cohort, we included treatment-naïve adults who commenced antiretroviral therapy (ART) from 1 January 2007; data were extracted on 30 September 2020. Viral blips were defined as transient plasma HIV RNA levels between 50 and 500 copies/mL preceded and followed by HIV RNA < 50 copies/mL. Virological failure was defined as two consecutive HIV RNA samples > 200 copies/mL or a single sample of HIV RNA > 1,000 copies/mL, in previously suppressed individuals with more than 12 months since ART initiation. Cox regression was used for event analyses.Results In total, 4,210 individuals were included, of whom 853 (20.3%) had 1-6 registered blips. Median observation time was 5.5 years (range 0.5-13.7). Blip incidence was 4.35 (95% CI 4.02-4.69) per 100 person-years. In a sensitivity analysis applying the narrower definition of 50-199 copies/mL, the incidence was 3.80 (95% CI 3.49-4.11) per 100 person-years. Individuals on INSTIs and NNRTIs had similar risk, while those on PIs had a significantly higher risk of blips (hazard ratio [HR] 1.22, 95% CI 1.03-1.45; p = 0.02). Transient viremia was not associated with an increased risk of subsequent virological failure; individuals with blips had a lower risk than those with continuously undetectable HIV RNA (HR 0.54, 95% CI 0.41-0.71; p < 0.0001).Conclusion Individuals on INSTI- and NNRTI-based ART had fewer viral blips than those on PI-based ART. In this cohort, transient viremia below 500 HIV RNA copies/mL was not associated with a higher risk of subsequent virological failure.Clinical trial number Not applicable.
SN - 1471-2334
ER -