EXPRESSION LEVELS OF IL-6 MESSENGER-RNA IN PBMNCS FROM PATIENTS WITH IDDM, NIDDM AND NORMALS BY RT-PCR PROCEDURE

Although it has been confirmed that insulin dependent diabetes mellitu s (IDDM) is a kind of autoimmune disease, islet cell autoantibodies (I CAs), insulin autoantibodies (IAA) and anti-GAD-glutamic acid decardax ylase antibodies have been found in the sera of patients with IDDM and immunotherapies have been used in some patients with IDDM, yet the ma nner in which the dysfunctional immunosystem acts on beta cells and ca uses damage to them remains to be clarified. Recently, possible involv ement of the abnormal production of IL-6 in autoimmune symptoms was su ggested in patients with cardiac myxomas, Castleman's disease and rheu matoid arthritis. However reports of IL-6 abnormal production in patie nts with IDDM are rare. In the present study, we examined whether or n ot an abnormal expression of IL-6 mRNA was present in mononuclear cell s (PBMNCs) of the peripheral blood of patients with IDDM. We devised a highly sensitive, specific and semiquantitative protocol, ie, reverse transcription and polymerase chain reaction (RT-PCR). We have used su ch an assay to measure the relative expression levels of IL-6 mRNA in PBMNCs from 12 early IDDM patients (duration < 6 mon, 8.20 +/- 3.85 yr ), 29 newly-diagnosed NIDDM patients (54.85 +/- 9.12 vr), 23 normal ch ildren (8.20 +/- 3.26 yr) and 12 normal adults (31.92 +/- 11.22 yr). I n this assay significantly high expression levels of IL-6 mRNA were fo und in PBMNCs from patients with IDDM (P<0.05). The relative levels we re 0.91 +/- 0.19; 0.10 +/- 0.06; 0.43 +/- 0.08; 0.10 +/- 0.07, respect ively. Our results suggest that higher expression levels of IL-6 MRNA in PBMNCs from patients with IDDM imply that IL-6 may play an importan t role in the pathogenesis of IDDM.