A low TIBC and UIBC may be associated with an excess of iron being carried in the blood, reflecting increased saturation of the transport protein transferrin, i.e., there is less binding capacity available as transferrin becomes more saturated.
There isn’t quite enough information available in your query (noted labs that were provided) to fully assess the situation. It is very important to know a client’s medical and treatment history in order to assess the set of labs provided. Had they been diagnosed with anemia and are receiving iron therapy? What is their medical history? How do current labs compare over more complete sets of blood work from past years?
In general, TIBC measures all iron-binding proteins but primarily reflects transferrin levels which decrease when an excess of iron is available. TIBC takes serum iron and unsaturated binding capacity (UIBC) into account. A decrease in TIBC should be investigated further as transferrin is a negative acute phase reactant and will decrease with inflammation and also with malignancy, collagen vascular disease, liver disease, and hypoproteinemia (Pagana 2019).
It would be prudent to fully review medical and laboratory history and repeat a comprehensive metabolic panel, inflammation markers, and CBC with differential that includes %reticulocytes.
Reference
Pagana, Kathleen Deska; Pagana, Timothy J.; Pagana, Theresa N. Mosby's Diagnostic and Laboratory Test Reference. Elsevier Health Sciences. 2019.