Can an impaired bone marrow affect hiv testing. will it delay seroconversion in hiv? 8 months exposure negative 4 generation combo lab test?

I think that if you have a bone marrow disease that impairs your production of immunoglobulins it's possible to have a false negative HIV test. Examples of such bone marrow diseases would be multiple myeloma and primary amyloidosis where low IgG,IgA&IgM immunoglobulins are common. A hematologist or infectious disease specialist could provide more information on this matter,however.

What is the evidence for impairment of bone marrow? Unless you have inherited immune deficiency that may have interfered with antibody formation, a negative Gen 4 test at 8 months after exposure excludes HIV.