Immunological Effects of Decidual Stromal Cell Treatment in Patients with Severe Chronic Graft-Versus-Host Disease

Introduction

Decidual stromal cells (DSCs) isolated from fetal membranes of term placentas, are easily expanded and highly immunosuppressive in vitro. DSCs have a high expression of integrins that are of importance for homing to damaged tissue. In the present study, we introduce DSCs as a cellular therapy for chronic Graft-versus-Host Disease (cGvHD).

Patients and Methods

Three patients (1 (ALL), 2 (AML), and 3 (CML)) with severe extensive cGvHD were treated with DSCs (1-2.8 x 10⁶ cells/kg). Patient 1 and 2 received two infusions and patient 3 received one dose. One third of DSCs administered to patient 1 and 2 were labelled with ¹¹¹Indium and the in vivo-distribution was tracked for 48h. Blood samples were obtained before and up to 4-10 weeks after the first infusion. Samples were analyzed by flow cytometry and luminex.

Results

All patients had cGVHD of skin, liver and obstructive bronchiolitis. Patients 1 and 2 are regarded as partial responders (PR) and patient 3 as a non-responder (NR). Response was evaluated according to the NIH guidelines for diagnosing cGvHD.

Patients receiving ¹¹¹In-DSCs showed the same distribution pattern of the isotope over time. The isotope was initially located in the lungs, followed by dissemination to liver and spleen.

The flow cytometry and luminex data are presented as the median frequency of data from all time points for each patient. Patient 3 had high frequencies of HLA-DR⁺ cells within the CD3⁺CD4⁺ cell population (Th) (median 72.9%, range 72.7-73.3%). The corresponding proportions in patients 1 and 2 were 21.5% (17.6-21.9) and 36.5% (25.8-50-8), respectively. Among CD3⁺CD8⁺cells (Tc), the frequency of HLA-DR-expression was 33.6% (30.9-37.5), 60.5% (56.7-68.1) and 80.6% (70.8-83.8) for patient 1, 2, and 3, respectively.

The percentage of Th-cells with a naïve (CD45RA⁺CCR7⁺) phenotype was 4.8% (3.6-6.3) in patient 3, but 24.4% (4.3-24.4) and 25.1% (11.2-26.3) in patient 1 and 2, respectively. The proportion of terminally differentiated (CD45RA^-CCR7⁺) Th-cells was 2.3% (2.1-2.6), 7.4% (2.4-8.7) and 12.7% (10.9-23.2) in patients 1, 2, and 3, respectively.

The frequency of Tregs (CD4⁺CD25^highCD127^low/-) was 11.5% (8.63-15.9) for patient 3, whereas they were 6.4% (4.8-6.5) and 3.3% (2.5-4.8) for patient 1 and 2, respectively.  Patient 3 had the highest proportion Th-cells with a Th17 (CD45RA^-CXCR3^-CCR4⁺CCR6⁺), Th1/Th17 (CD45RA^-CXCR3⁺CCR4^-CCR6⁺) and Th2 phenotype (CD45RA^-CCR4⁺CXCR3^-CCR6^-). Patient 3 also had the highest median plasma concentrations of IL-17, IL-4 and IFN-γ.

Discussion

DSCs are safe to infuse with no adverse effects. We determined how stromal cells are distributed in vivo following infusion in a GvHD setting. The data also support that the non-responder had a more activated/exhausted immune system than the partial responders. This study may provide a basis for further controlled investigations into use of DSCs as a treatment for severe cGvHD.