Charles F. McTiernan, Penelope Morel, Leslie T. Cooper, Navin Rajagopalan, Vinay Thohan, Mark Zucker, John Boehmer, Biykem Bozkurt, Paul Mather, John Thornton, Jalal K. Ghali, Karen Hanley-Yanez, James Fett, Indrani Halder, Dennis M. McNamara, IPAC Investigators, Dennis M. McNamara, James D. Fett, Jessica Pisarcik, Charles McTiernan, Karen Hanley-Yanez, John Gorcsan, Erik Schelbert, Rami Alharethi, Kismet Rasmusson, Kim Brunisholz, Amy Butler, Deborah Budge, A.G. Kfoury, Benjamin Horne, Joe Tuinei, Heather Brown, Julie Damp, Allen J. Naftilan, Jill Russell, Darla Freehardt, Eileen Hsich, Cynthia Oblak, Greg Ewald, Donna Whitehead, Jean Flanagan, Anne Platts, Uri Elkayam, Jorge Caro, Stephanie Mullin, Michael M. Givertz, M. Susan Anello, Navin Rajagopalan, David Booth, Tiffany Sandlin, Wendy Wijesiri, Leslie T. Cooper, Lori A. Blauwet, Joann Brunner, Mary Phelps, Ruth Kempf, Kalgi Modi, Tracy Norwood, Joan Briller, Decebal Sorin Griza, G. Michael Felker, Robb Kociol, Patricia Adams, Gretchen Wells, Vinay Thohan, Deborah Wesley-Farrington, Sandra Soots, Richard Sheppard, Caroline Michel, Nathalie Lapointe, Heather Nathaniel, Angela Kealey, Marc Semigran, Maureen Daher, John Boehmer, David Silber, Eric Popjes, Patricia Frey, Todd Nicklas, Jeffrey Alexis, Lori Caufield, John W. Thornton, Mindy Gentry, Vincent J.B. Robinson, Gyanendra K. Sharma, Joan Holloway, Maria Powell, David Markham, Mark Drazner, Lynn Fernandez, Mark Zucker, David A. Baran, Martin L. Gimovsky, Natalia Hochbaum, Bharati Patel, Laura Adams, Gautam Ramani, Stephen Gottlieb, Shawn Robinson, Stacy Fisher, Joanne Marshall, Jennifer Haythe, Donna Mancini, Rachel Bijou, Maryjane Farr, Marybeth Marks, Henry Arango, Biykem Bozkurt, Mariana Bolos, Paul Mather, Sharon Rubin, Raphael Bonita, Susan Eberwine, Hal Skopicki, Kathleen Stergiopoulos, Ellen McCathy-Santoro, Jennifer Intravaia, Elizabeth Maas, Jordan Safirstein, Audrey Kleet, Nancy Martinez, Christine Corpoin, Donna Hesari, Sandra Chaparro, Laura J. Hudson, Jalal K. Ghali, Zora Injic, Ilan S. Wittstein

Evaluate the hypothesis that the distribution of circulating immune cell subsets, or their activation state, is significantly different between PPCM and healthy postpartum (HP) women. Peripartum cardiomyopathy (PPCM) is a major cause of maternal morbidity and mortality and an immune-mediated etiology has been hypothesized. Cellular immunity, altered in pregnancy and the peripartum period, has been proposed to play a role in PPCM pathogenesis. The Investigation of Pregnancy Associated Cardiomyopathy (IPAC) study enrolled 100 women presenting with an LVEF<0.45 within two months of delivery. Peripheral T-cell subsets, Natural Killer (NK) cells, and cellular activation markers were assessed by flow-cytometry in PPCM women early (<6 weeks), 2 months, and 6 months postpartum, and compared to those of healthy postpartum (HP) women, and women with non-pregnancy associated recent onset cardiomyopathy (ROCM). Entry NK cell levels (CD3-CD56+CD16+; reported as % of CD3- cells) were significantly (p<0.0003) reduced in PPCM (6.6±4.9% of CD3- cells) compared to HP (11.9±5%). Of T-cell subtypes, CD3+CD4-CD8-CD38+ cells differed significantly (p<0.004) between PPCM (24.5±12.5% of CD3+CD4-CD8- cells) and HP (12.5±6.4%). PPCM patients demonstrated a rapid recovery of NK and CD3+CD4-CD8-CD38+ cell levels. However black women had a delayed recovery of NK cells. A similar reduction of NK cell was observed in women with ROCM. Compared to HP controls, early postpartum PPCM women show significantly reduced NK cells, and higher CD3+CD4-CD8-CD38+ cells, which both normalize over time postpartum. The mechanistic role of NK cells and "double negative" (CD4-CD8-) T regulatory cells in PPCM requires further investigation.