Table 1.
Second line tests in the differential diagnosis of CS vs. pCS. Δ = Delta, dex = dexamethasone, CRH = Corticotropin Realising Hormone, DDAVP = Desmopressin, CS = Cushing’s Syndrome, CD = Cushing’s Disease, pCS = pseudo-Cushing’s syndrome, ACS = Adrenal Cushing’s Syndrome, EAS = Ectopic ACTH Secretion, Se = Sensitivity, Sp = Specificity. *Paediatric patients
| Study | Test | CS | pCS / controls | Cut-off | Se (%) | Sp (%) |
|---|---|---|---|---|---|---|
| Yanovski JA, 1993 | Dex-CRH | CD 35, ACS 2, EAS 2 | pCS 19 | Cortisol at 15′: 38 nmol/L (1.4 µg/dL) | 100 | 100 |
| Martin NM, 2006 | Dex-CRH | CD 8, ACS 4 | pCS 3, controls 16 | Cortisol at 15′: 50 nmol/L (1.8 µg/dL) | 100 | 88 |
| Gatta B, 2007 | Dex-CRH | CD 17 (mild) | pCS 14 | Cortisol at 15′: 110 nmol/L (4 µg/dL) | 100 | 86 |
| ACTH at 15′: 3.5 pmol/L (16 pg/mL) | 100 | 85 | ||||
| Erickson D, 2007 | Dex-CRH | CD 21 | pCS 30 | Cortisol at 15′: 70 nmol/L (2.5 µg/dL) | 90 | 90 |
| ACTH at 15′: 5.9 pmol/L (27 pg/mL) | 95 | 97 | ||||
| Pecori-Giraldi F, 2007 | Dex-CRH | CD 29, ACS 3 | pCS 23 | Cortisol at 15’: 75 nmol/L (2.7 µg/dL) | 100 | 82 |
| Reimondo G, 2008 | Dex-CRH | CD 13, ACS 3 | pCS 15 | Cortisol at 15′: 44 nmol/L (1.6 µg/dL) | 93.7 | 93.3 |
| Valassi E, 2009 | Dex-CRH | CD 60 | pCS 41 | Cortisol at 15′: 38 nmol/L (1.4 µg/dL) | 86.3 | 84.7 |
| Alwani RA, 2014 | Dex-CRH | CD 53 | pCS 20 | Cortisol at 15′: 87 nmol/L (3.2 µg/dL) | 94 | 100 |
| Batista D, 2008* | Dex-CRH | CS 11 | pCS 11 (Obese) | Cortisol at 15′: 88 nmol/L (3.2 µg/dL) | 91 | 95 |
| Yanovski JA, 1993 | CRH | CD 35, ACS 2, EAS 2 | pCS 19 |
Sum of post-CRH cortisol levels > 3450 nmol/L (125 µg/dL) |
64 | 100 |
| Arnaldi G, 2009 | CRH | CD 51, EAS 7 | pCS 26, controls 31 |
Basal serum cortisol > 331 nmol/L (12 µg/dL) and ACTH peak > 12 pmol/L (54 pg/mL) |
91.3 | 98.2 |
| Tirabassi G, 2011 | CRH | CD 30 | pCS 18, controls 12 |
Basal serum cortisol > 331 nmol/L (12 µg/dL) and ACTH peak > 12 pmol/L (54 pg/mL) |
96.6 | 100 |
| Malerbi DA, 1996 | DDAVP | CD 14 | pCS 11 | Δ-Cortisol ≥ 4 times intra-assay variation coefficient | 100 | 64 |
| Moro M, 2000 | DDAVP | CD 76 | pCS 30, controls 67 | Δ-ACTH ≥ 6 pmol/L 0’ – 30′ (27.2 pg/mL) | 86.8 | 90.7 |
| CD 20 (mild) | pCS 30 | 90 | 96.7 | |||
| Pecori-Giraldi F, 2007 | DDAVP | CD 27 | pCS 21 | Δ-ACTH ≥ 6 pmol/L 0’ – 30′ (27.2 pg/mL) | 81.5 | 90 |
| Tirabassi G, 2010 | DDAVP | CD 52 | pCS 28, controls 31 | Δ-ACTH > 6 pmol/L 0’ – 30′ (27.2 pg/mL) | 75 | 89.8 |
| Basal serum cortisol > 331 nmol/L (12 µg/dL) and Δ-ACTH > 4 pmol/L (18 pg/mL) | 90.3 | 91.5 | ||||
| Tirabassi G, 2011 | DDAVP | CD 30 | pCS 18, controls 12 | Basal serum cortisol > 331 nmol/L (12 µg/dL) and Δ-ACTH > 4 pmol/L (18 pg/mL) | 96.6 | 100 |
| Rollin G, 2015 | DDAVP | CD 68 | pCS 56 | Peak ACTH of 15.8 pmol/L (36.8 pg/mL) | 90.8 | 94.6 |
| Δ-ACTH ≥ 8.1 pmol/L 15′–30′ | 88 | 96.4 | ||||
| Araya V, 2017 | Dex-DDAVP | CD 36 | pCS 9, controls 7 | Δ-Cortisol ≥ 166 nmol/L (6 µg/dL) | 96.9 | 93.7 |