Simplifying Inferior Petrosal Sinus Sampling: Results of a Multicenter Study

Introduction: Inferior petrosal sinus sampling (IPSS) is an important method for confirming a central source and lateralization for adrenocorticotrophin (ACTH) secretion in Cushing’s disease (CD), though it is technically challenging requiring synchronized blood draws at numerous time points before and after stimulation We explored IPSS results from a multicenter experience to determine if it might be possible to decrease the number of blood draws and retain diagnostic utility.

Methods: Patients from the Registry of Adenomas of the PItuitary and Related Disorders (RAPID) who underwent IPSS for management of CD were included. An analysis of surgical characteristics and laboratory values as well as stimulation protocols and response was performed. Lateralized IPSS ACTH levels with the highest values were normalized to peripheral levels.

Results: Of the 780 patients who were included, 108 underwent IPSS. No differences in baseline characteristics were seen but a higher number of patients with IPSS had MRI-negative disease (81.8 vs. 66.1%, p = 0.02) and long-term remission (71.9 vs. 57.8%, p = 0.01). Among patients with IPSS, 93/108 (86.11%) demonstrated positive pathology or long-term disease remission. Stimulation paradigms showed a 5.0-, 4.6-, and 4.2-fold increase in IPSS ACTH at 2, 5, and 10 minutes poststimulation at the lateralized side of IPSS sampling compared with nonlateralized side, respectively. A 2.4-fold increase in IPSS at the localized side compared with baseline was seen at 2 minutes poststimulation. Both corticotrophin releasing hormone (CRH) and desmopressin (DDAVP) showed best response in ACTH levels around 2 to 5 minutes poststimulation. Patients with long-term remission showed a greater stimulation response also at 2 to 5 minutes compared with those who did not have long-term remission or positive pathology.

Discussion: Pituitary teams can use these data suggesting that stimulation responses of 2.4× from baseline at 2 minutes can indicate a positive response. A four to five times difference between 2 and 10 minutes was seen in lateralizing ACTH responses. These results may help with reducing testing burden on patients and decrease the complexity of the test.

Fig. 1 Normalized ACTH levels during IPSS for localized and nonlocalized sides.

Fig. 2 Normalized ACTH to PRL levels during IPSS for localized and nonlocalized sides.

Fig. 3 Normalized ACTH levels for DDAVP vs. CRH stimulation during IPSS for localized and nonlocalized sides.

Fig. 4 Normalized ACTH levels for patients with and without remission/pathology during IPSS for localized and nonlocalize sides.

Publikationsverlauf

Artikel online veröffentlicht:
07. Februar 2025