Frequency of Macroprolactinemia in Hyperprolactinemic Women Presenting with Menstrual Irregularities, Galactorrhea, and/or Infertility: Etiology and Clinical Manifestations

Table 1

Demographic and clinical data, serum total and free immunoreactive prolactin (PRL) levels, distribution of PRL immunoreactivity in three fractions obtained after gel filtration, and percentage of retained PRL in affinity chromatography in hyperprolactinemic patients according to the absence or presence of macroprolactinemia (MPRL).

Variable	Without MPRL (𝑛=269)	With MPRL (𝑛=57)	𝑃 value
Age, yrs, mean ± SD	33.6±8.9	32.9±9.1	0.62^b
Body mass index, mean ± SD	27.4±4.8	27.7±4.1	0.72^b
Direct PRL, ng/mL, median (range)	38.1 (25.5–1,860.0)	42.0 (26.0–268.6)	0.27^c
Free PRL, ng/mL, median (range)	31.7 (25.5–1,840)	9.2 (2.2–22.2)	<0.001^c
Big big PRL (%), mean ± SD	2.9±1.2	72.0±11.2	<0.001^b
Big PRL (%), mean ± SD	2.5±2.4	3.1±2.1	0.85^b
Little PRL (%), mean ± SD	96.0±8.7	24.9±10.1	<0.001^b
IgG-bound PRL (%), mean ± SD^a	0.8±1.4	38.5±4.5	<0.001^b
Anti-PRL autoantibodies (%)	0 (0)	54 (94.7)	<0.001^d
Oligomenorrhea or amenorrhea (%)	116 (44.8)	28 (49.1)	0.50^d
Galactorrhea (%)	91 (33.8)	7 (12.3)	0.002^d
Infertility (%)	85 (31.6)	21 (36.8)	0.54^d
Alterations in libido (%)	13 (4.8)	1 (1.8)	0.50^e
Secondary hyperprolactinemia (%)	81 (30.1)	6 (10.5%)	0.004^d
Polycystic ovarian syndrome (%)	22 (8.2)	4 (7.0)	0.93^e
Dopamine agonist prescribed (%)	147 (54.6)	44 (77.2)	0.003^d

aPRL retained in protein G-Sepharose column (PRL retained/PRL nonretained + PRL retained × 100%).
bNonpaired Student’s 𝑡-test, ^cMann-Whitney 𝑈-test, ^d𝜒² test, and ^eFisher’s exact test.