Peripheral blood B lymphocytes derived from patients with idiopathic pulmonary arterial hypertension express a different RNA pattern compared with healthy controls: a cross sectional study.
BACKGROUND
Idiopathic pulmonary arterial hypertension (IPAH) is a progressive and still incurable disease. Research of IPAH-pathogenesis is complicated by the lack of a direct access to the involved tissue, the human pulmonary vasculature. Various auto-antibodies have been described in the blood of patients with IPAH. The purpose of the present work was therefore to comparatively analyze peripheral blood B lymphocyte RNA expression characteristics in IPAH and healthy controls.


METHODS
Patients were diagnosed having IPAH according to WHO (mean pulmonary arterial pressure > or = 25 mmHg, pulmonary capillary occlusion pressure < or = 15 mmHg, absence of another explaining disease). Peripheral blood B-lymphocytes of patients and controls were immediately separated by density gradient centrifugation and magnetic beads for CD19. RNA was thereafter extracted and analyzed by the use of a high sensitivity gene chip (Affymetrix HG-U133-Plus2) able to analyze 47000 transcripts and variants of human genes. The array data were analyzed by two different softwares, and up-and down-regulations were defined as at least 1.3 fold with standard deviations smaller than fold-changes.


RESULTS
Highly purified B-cells of 5 patients with IPAH (mean pulmonary artery pressure 51 +/- 13 mmHg) and 5 controls were analyzed. Using the two different analyzing methods we found 225 respectively 128 transcripts which were up-regulated (1.3-30.7 fold) in IPAH compared with healthy controls. Combining both methods, there were 33 overlapping up-regulated transcripts and no down-regulated B-cell transcripts.


CONCLUSIONS
Patients with IPAH have a distinct RNA expression profile of their peripheral blood B-lymphocytes compared to healthy controls with some clearly up-regulated genes. Our finding suggests that in IPAH patients B cells are activated.
Ulrich
Silvia
S
Department of Internal Medicine, Pulmonary Hypertension Clinic, University Hospital of Zurich, Zurich, Switzerland. ulris@bluewin.ch
Taraseviciene-Stewart
Laima
L
Huber
Lars C
LC
Speich
Rudolf
R
Voelkel
Norbert
N
D000328:Adult; D001402:B-Lymphocytes / Q000166:cytology*; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D006976:Hypertension, Pulmonary / Q000097:blood* / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D040081:Protein Array Analysis; D040901:Proteomics; D012313:RNA / Q000235:genetics*; D012016:Reference Values; D012680:Sensitivity and Specificity; D015854:Up-Regulation
D012313:RNA