Evidence for the "fitness" effect comes from the temporal association between loss of resistance phenotype and the steepest changes in surrogate markers
. Studies by Stephen Deeks and colleagues have also given credence to this hypothesis.
Though such strong correlation in short term (3 month) follow up used in this study is an indicator of usefulness of albumin as a surrogate marker
but for further assessment of its effect on mortality needs a longer duration of follow up in a bigger study cohort as had been shown before in the study done by Mehta et al.
Overall, we believe that our findings support the potential use of qPCR to detect the presence of [bIa.sub.OXA-23] gene directly from ETAs, and possibly the detection of other carbapenemase-encoding genes, such as [bIa.sub.OXA-143] gene for example, which has been shown to be highly prevalent in some Brazilian Southeastern cities, (5) as surrogate marker
for the presence or absence of CRAB in patients under mechanical ventilation.
Nevi counts are associated with UV exposure, and can be used as a surrogate marker
for UV-induced cutaneous damage.
In a commentary, the CDC noted that prior research has shown that norovirus can be transmitted to fomites and that a surrogate marker
for norovirus, feline calcivirus, has been shown to survive on computer mouses and keyboards for up to 2 days.
In other words, was the endpoint chosen for the study correct for the condition being studied (i.e., an objective marker or validated surrogate marker
Low levels of WNV antibodies in nestlings could serve as a surrogate marker
of exposure in adult raptor populations.
Birth weight is a gross surrogate marker
for shifts in a host of metabolic processes.
Sometimes the therapy itself may alter the predictive value of a surrogate marker
. For example, Steven Deeks, MD, has shown that HIV-infected patients who remain on a protease inhibitor do better clinically than their viral loads would indicate.
The treatment certainly did increase HIV-specific immunity as shown by lymphocyte proliferation assay (p[less than]001),  but this measure is not currently accepted as a surrogate marker
of drug efficacy, because there is no proof at this time that increasing this response is clinically beneficial to patients.
Historical rates do not exceed 50% in this disease setting; serum levels of antigen-specific IgG, against both individual WT1 peptides within GPS and the full-length WT1 protein, were induced in 86% of patients; achievement of high titers of WT1-specific IgG post-GPS results from Immunoglobulin M to IgG class switching, the latter being a surrogate marker
of induction of activated T-helper cells after vaccination.
Thus, keeping TLC as the main surrogate marker
, monitoring Haemoglobin, Body Mass Index and Serum albumin levels will provide us a sensitive low cost prediction of the CD4 count along with the progression of the disease in HIV/AIDS.