Is the definition of late diagnosis correct?

Background: The study analysed 1711 patients of the Hospital for Infectious Diseases in Warsaw diagnosed with HIV infection in 2008-2010 and 2016-2018. Research was conducted examining the changes in CD4 cell counts before starting antiretroviral (ARV) treatment in order to find people who were misclassified as late-diagnosed. Methods: Patients with late diagnosis were distinguished on the basis of the consensus definition. The Mann-Whitney U-test was used to analyse the change in CD4 cell counts before starting ARV treatment. Results: In the years 2008-2010, the CD4 count was remeasured before starting ARV treatment in 90 late-diagnosed patients. The median change in the CD4 count was 22 cells/mu L. In 49 of these, the number of CD4 cells spontaneously increased before the start of treatment. We can suspect that these patients were misclassified as late-diagnosed. Conclusions: The consensus definition of late diagnosis often leads to overestimation of the number of late-diagnosed patients. The crucial problem is a transient decline in the CD4 lymphocyte count in the acute phase of HIV infection. A potential solution is to introduce serum HIV viral load measurement into the definition.