Acute Hypersensitivity Reaction (AHR)/ Gadolinium Deposition Disease (GDD) / Nephrogenic Systemic Fibrosis. A brief revisit.

Acute hypersensitivity Reaction (AHR)  primarily involves Mast Cells, GDD primarily involves tissue resident T memory cells, and NSF involves cd34+ bone marrow cell infiltrates, with circulating fibrocytes being the primary cell type. None of these conditions probably are pure 1 cell type. So GDD probably quite often is a persistent reaction that started with MAST Cells. then transitions to primarily T cell. GDD probably also involves some variable amount of cd 34+ immune cells. The cell infiltration in NSF is strange because  the immune system has jumped to the end of the immune system armamentarium to battle foreign invaders, which usually occurs when everything else has failed.  I think it is because there are cofactors related to either chronic renal failure on its own, or medications used to treat chronic renal failure (such as Lanthanum-containing meds). I am not convinced pure NSF occurs in the setting of normal kidneys. I think it is GDD, and maybe GDD with a mixture of NSF components.

The most common combination appears to be AHR/ GDD. Individuals with GDD where symptoms started immediately after GBCA injection. This also is observed as symptoms that re-ignite immediately after iv DTPA chelation. My impression is that individuals who develop severe AHR symptoms should not only receive iv benadryl (antihistamine) and iv steroid, but also iv Ca-DTPA.

Richard Semelka, MD