Suppressed diversity of survivin splicing in active rheumatoid arthritis

• Published in: Arthritis research & therapy Vol. 17; no. 1; p. 175
• Main Authors: Turkkila, Minna, Andersson, Karin M E, Amu, Sylvie, Brisslert, Mikael, Erlandsson, Malin C, Silfverswärd, Sofia, Bokarewa, Maria I
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 10.07.2015; BioMed Central
• Subjects: Adult; Aged; Alternative Splicing - physiology; Analysis; ANTI-CD20 TREATMENT; ANTIBODIES; APOPTOSIS PROTEIN; Arthritis; Arthritis, Rheumatoid - blood; Arthritis, Rheumatoid - diagnosis; Arthritis, Rheumatoid - genetics; Autoantibodies - blood; Autoantibodies - genetics; Autoimmunity; B cells; Biomarkers - blood; BREAST-CANCER; Care and treatment; CELL-DEATH; CLINICAL-RESPONSE; DOWN-REGULATION; Female; Genetic aspects; Humans; Immunoglobulin A; Inhibitor of Apoptosis Proteins - blood; Inhibitor of Apoptosis Proteins - genetics; Leukocytes, Mononuclear - metabolism; LOCALIZATION; Male; Medicin och hälsovetenskap; Middle Aged; Reumatologi och inflammation; Rheumatoid factor; Rheumatology; Rheumatology and Autoimmunity; RITUXIMAB; VARIANT EXPRESSION
• ISSN: 1478-6354; 1478-6362; 1478-6362; 1478-6354
• DOI: 10.1186/s13075-015-0689-z

Alternative splicing distinguishes normal and pathologic cells. High levels of oncoprotein survivin recognise patients with severe rheumatoid arthritis (RA). Here, we assess clinical relevance of alternative splicing of survivin in leukocytes of peripheral blood (PBMC) and bone marrow (BM) in RA patients. Transcription of survivin wild-type (survivin-WT), survivin-2B and survivin-ΔEx3 was measured in 67 randomly selected RA patients and in 23 patients before and after B cell depletion with rituximab. Analysis was done in relation to disease activity, anti-rheumatic treatment and serum levels of rheumatoid factor (RF) and survivin. Survivin-WT was the dominant splice variant equally expressed in T and B cells, while survivin-2B and survivin-ΔEx3 were higher in B cells. High disease activity (DAS28>5.1) was associated with an excess of survivin-WT and low ratios between survivin-2B/WT (p=0.035) and survivin-ΔEx3/WT in PBMC. Depletion of B cells by rituximab caused a decrease in survivin-WT (p=0.005) in PBMC, increasing the ratio between survivin-2B/WT (p=0.009) and survivin-ΔEx3/WT (p=0.001) in BM. This increase in survivin-2B/WT was associated with reduction in CD19+ BM cells (r=0.929, p=0.007), RF (IgM, r=0.857, p=0.024; IgA, r=0.739, p=0.021), and DAS28 (0.636, p=0.054). The increase in survivin-ΔEx3 in BM was associated with a reduction of CD19+ BM cells (r=0.714, p=0.058) and DAS28 (r=0.648, p=0.049), while survivin-ΔEx3/WT was associated with RF (IgG, r=0.882, p=0.016). This study demonstrates that the suppressed diversity of survivin splicing in leukocytes may attribute to adverse self-recognition in RA. Depletion of autoantibody producing B cells improves the balance of survivin splicing.