This patient presents with signs and symptoms of neutropenia, namely fever, chills, lethargy, weakness, and sore throat. Agranulocytosis is associated with clozapine. Patients taking this medication should regularly have an absolute neutrophil count (ANC) monitored and should be monitored for signs of neutropenia. Low serum blood glucose would typically present with altered mental status and confusion, not fevers, chills, and sore throat. Elevated lymphocyte count could be associated with a viral infection or lymphoma, but this is a less likely diagnosis. Low CD4+ T cell count would be characteristic of HIV infection which could present in a similar way, but, due to the recent prescription of clozapine, neutropenia in this patient is much more likely.