A diagnostic Western blot for HIV requires reactivity to at least two of several defined bands to be considered positive. If a patient's blot shows faint bands at p24 and gp41 barely above background, how should a lab interpret the faintness of bands, and what follow-up is most appropriate?

• A. Report the patient immediately as positive for HIV since presence of any band at any intensity always meets confirmatory criteria irrespective of clinical context or assay validation specifics.
• B. Perform a western transfer again but reverse the blot orientation so faint bands will become stronger due to gravitational effects on antibody binding, then report the stronger bands as definitive evidence.
• C. Any faint band should be treated as negative because only strong bands are considered diagnostic; therefore report the result as negative and no further testing is warranted.
• D. Faint bands can still indicate presence of specific antibodies but might reflect low antibody titer or early/late infection; the lab should consider the faint bands in the context of clinical history, repeat testing or confirm with an orthogonal assay (e.g., repeat ELISA or nucleic acid test) to corroborate results before reporting definitive status.

Answer: (D)