Extra-nodal Lymphoid Microstructures in Inflamed Muscle and Disease Severity of New-Onset Juvenile Dermatomyositis

  • Histological patterns of cellular aggregates in GC in tonsil
    Figure 1S. Histological patterns of cellular aggregates in GC in tonsil.

    Sections of tonsil show CD20+ B cells (arrowheads) in the center of lymphoid follicles and CD3+ T cells (arrows) were distributed around the B cells (M-O). All magnifications: x 40.

Figure 1S. Histological patterns of cellular aggregates in GC in tonsil.
  • Microchimerism of lymphoid follicle-like structures in JDM muscle and in peripheral blood.
    Figure 2S. Microchimerism of lymphoid follicle-like structures in JDM muscle and in peripheral blood.

    Muscle tissue of male JDM patients with follicle-like structures (A-C; magnifications x250), peripheral blood CD34+ cells (D) or lymphocyte aggregates (E-F) were subjected to FISH. Hybridization probes for X and Y chromosome were labelled with Spectrum Orange (red, A) and Spectrum green (green, B) respectively. Photomicrograph in C (merged image) shows a female XX cell (two red spots in a single nucleus with intact borders, white arrowhead) surrounded by male XY cells (white arrows indicate Y chromosome). Figure 6D demonstrates PBMC of male JDM patients sorted for the expression of CD34 and subjected to FISH staining. Photomicrograph shows the presence of female XX (two red spots in a single nucleus with intact border, arrowhead) along with male XY cells (arrow; one green and one red signal). Nuclei were counterstained with DAPI (blue). Magnification: x100. Immunophenotypes of XX cells were better discriminated in lymphocyte aggregates due to lower cell density and less overlap of cells relative to follicle-like structure. As depicted in E and F (magnifications x100), there was CD20 and X-probe co-localized. Similar co-localization of X-probe and the pDC marker CD123 was also found (not shown).

Figure 2S. Microchimerism of lymphoid follicle-like structures in JDM muscle and in peripheral blood.

The information presented here supplements an article in Arthritis & Rheumatism on “Extra-nodal Lymphoid Microstructures in Inflamed Muscle and Disease Severity of New-Onset Juvenile Dermatomyositis”.

Consuelo M. López de Padilla1 MD, Abbe N. Vallejo PhD, David Lacomis3 MD, Kelly McNallan1 BS and Ann M. Reed MD

1Division of Rheumatology, Departments of Medicine, Pediatrics, and Immunology, Mayo Clinic College of Medicine, Rochester, MN 55905; 2Departments of Pediatrics and Immunology, Children’s Hospital of Pittsburgh, Pittsburgh Cancer Institute, and McGowan Institute for Regenerative Medicine; and, 3Department of Pathology, Division of Neuropathology; University of Pittsburgh School of Medicine, Pittsburgh, PA 15213.

§Corresponding authors: Dr. Ann M. Reed (reed.ann18@mayo.edu), Division of Rheumatology, Departments of Medicine and Pediatrics, Mayo Clinic, 200 First Street SW, Rochester MN 55905 Phone 507-284-4277, Fax 507-284-0564; Dr. Abbe N. de Vallejo (andv26@pitt.edu), Department of Pediatrics, Children’s Hospital of Pittsburgh Rangos Research Center, University of Pittsburgh, Pittsburgh, PA 15213.