Urinary excretion of albumin, beta-2-microglobulin and light chains in pre-eclampsia, essential hypertension in pregnancy and normotensive pregnant and non-pregnant control subjects

Abstract

Urinary albumin, beta-2-microglobulin (β₂m) and light chain excretions were determined in first, second and third trimester of pregnancy and 5 days, 3 months and 6 months after delivery in patients with pre-eclampsia, essential hypertension and transient hypertension in pregnancy, and in normotensive pregnant and non-pregnant control subjects. In pre-eclampsia, albumin excretion was markedly reduced after delivery and did not deviate significantly from either the normotensive non-pregnant control group or the normotensive pregnant control group 6 months after delivery; light chain exeretion in pregnancy and 5 days after parturition was higher than in both normotensive non-pregnant and pregnant control subjects. In essential hypertension, albumin excretion was higher 5 days after delivery than in non-pregnant control subjects and reduced on examination 3 and 6 months later, but still significantly higher than in the normotensive control groups. In transient hypertension and normotensive pregnant subjects, albumin excretion was elevated only 5 days after delivery. Beta-2-microglobulin and light chain excretions were higher during pregnancy and 5 days after delivery in essential and transient hypertension and normotensive pregnant control subjects compared to non-pregnant control subjects. The results showed that the protein excretion pattern became normal in all patients with pre-eclampsia, and that both normal pregnancy and essential and transient hypertension in pregnancy was associated with a decrease in tubular reabsorption of protein. The increased albumin excretion shortly after delivery may be of postrenal origin.

Key Words:

• Albumin
• Albuminuria
• beta-2-microglobulin
• blood pressure
• essential hypertension
• glomerulus
• light chains
• pre-eclampsia
• pregnancy
• proteinuria
• tubulus