Expression analysis of leukocytes attracting cytokines in chronic histiocytic intervillositis of the placenta.

UNLABELLED

Chronic histiocytic intervillositis of the placenta (CHI) is a rare and potentially recurrent disease. Characteristically it shows accumulation of CD68+ cells in the intervillous space but no destructive tissue infiltration. An immunopathological background is likely but it is unknown what attracts circulating monocytes to the placenta.

METHODS

We analysed the expression profile of 102 inflammation- and angiogenesis-associated genes with real-time reverse transcriptase-polymerase chain reaction (RT-PCR) in 16 placentas: CHI (n = 5) and, as controls, villitis of unknown aetiology (VUE, n = 4) and normal placenta (n = 7).

RESULTS

Compared to controls, CHI had significantly higher levels of matrix metallopeptidase 9 (MMP9) and transforming growth factor, beta receptor 1 (TGFBR1). MMP14 was lower in VUE than CHI (p < 0.05) and controls (not significant). Chemokine (C-X-C motif) ligand 9 (CXCL9), CXCL12, chemokine (C-C motif) ligand 5 (CCL5) and TIMP metallopeptidase inhibitor 1 (TIMP1) were significantly higher in VUE versus controls but not deregulated in CHI. The expression profile could not clearly discriminate CHI from VUE or controls but a tendency for grouping of massive CHI was found. Angiogenesis-associated factors were not deregulated in CHI.

CONCLUSION

The discrepancy of massive histiocytic accumulation and the lack of striking up-regulation of cytokines might be the basis of the non-destructive behaviour of the histiocytes in CHI.