Which of the following outcomes is less commonly observed in routine blood transfusion recipients with GVHD?

In the context of transfusion-associated graft-versus-host disease (GVHD), pancytopenia is indeed less commonly observed compared to the other listed outcomes. GVHD occurs when donor lymphocytes attack the recipient's tissues, which can happen in immunocompromised individuals or in cases where HLA mismatching occurs.

The hallmark manifestations of GVHD typically include skin, liver, and gastrointestinal involvement, which can lead to serious complications. Skin rashes, liver dysfunction, and gastrointestinal symptoms are more commonly reported. While patients may experience increased susceptibility to infections due to the compromised immune system, this is a consequence of the underlying condition rather than a direct result of GVHD.

Pancytopenia, defined as a reduction in red blood cells, white blood cells, and platelets, can occur due to a variety of factors, including bone marrow suppression or infiltration by neoplastic processes. However, in the specific situation of GVHD post-transfusion, it does not present as a principal or common outcome. This makes it less prevalent among routine transfusion recipients diagnosed with GVHD when compared to the other outcomes listed in the question.