Background Dendritic cells (DCs) are antigen presenting cells with the ability to induce primary immune responses and preserve immunological tolerance during normal pregnancy. Prolactin (PRL) plays an important role as an immunostimulator hormone-cytokine and it is considered to be associated with fetal loss and systemic lupus erythematosus (SLE) activity during pregnancy. However, the interaction between DCs and PRL in the gestational period of SLE patients is unknown.
Objectives To determine the PRL and DCs concentrations in pregnant patients with SLE and its relationship with lupus activity and obstetric outcome.
Methods Pregnant patients with SLE from the Pregnancy and Autoimmune Rheumatic Diseases Clinic of CMN “La Raza” IMSS Mexico, and healthy pregnant women (controls) were included. All patients were under treatment with low doses of prednisone (< 15 mg/day) and chloroquine (150 mg /day). Peripheral blood was drawn for the PRL analysis by quimioluminiscense (IMMULITE 2000 Prolactin) and DCs: DC1 (monocytoid, immunogenic cells) and DC2 (plamocytoid, tolerogenic cells), by flow cytometer. These determinations were determined each trimester of pregnancy using specific antibodies. The PRL results were expressed in ng/dL and the DCs in percentages. The m-SLAM scale was used to measure the SLE activity each trimester of pregnancy (clinical activity: score ≥4). For the statistical analysis we used Student’s T test and Pearson correlation. The significant level was considered as p< 0.05.
Results We included 13 pregnant women with SLE and 11 healthy pregnant women. The mean age of SLE patients was 25.67 ± 3.84 and 29.2 ± 5.3 years old in the control group. The m-SLAM was 0.62 (0-3). All SLE patients were in clinical remission. The mean DC1 for the SLE patients was 11.42 ± 9.4 vs. 56.15 ± 22.32 in healthy pregnant women (p<0.01). The mean DC2 in SLE was 10.5 ± 8.7 vs. 20.49 ± 14.4 for the control group (p<0.02). Serum PRL concentrations in SLE patients were 166 ± 23.24 ng/dl vs. 148.5±69.8 in the controls (p=ns). Pearson analysis showed a trend of positive correlation between PRL and DC1 (r = 0.36, p = 0.1) in patients with SLE. The analysis of the third trimester showed the same trend of positive correlation (r = 0.42, p = 0.12) between DC1 and PRL. No correlation was found between DC1, DC2 and SLE activity. To date, twelve patients have had normal deliveries.
Conclusions This study shows a significant decrease in DCs (DC1 / DC2) in SLE patients compared with healthy pregnant women. We did not found a significant correlation between PRL and DC1 (immunogenic) in SLE. These results are directly related to the absence of SLE activity in pregnancy. There is a close relationship between SLE clinical remission, positive obstetric outcome, normal serum PRL concentrations, and low levels of DCs.
Disclosure of Interest None Declared