Increased frequency and specific reactivity of serum antinuclear antibodies in patients with nonimmune chronic idiopathic neutropenia of adults

This study describes the frequency of serum organ-specific and organ-nonspe cific autoantibodies in 157 patients with nonimmune chronic idiopathic neut ropenia of adults (NI-CINA). Forty-two age- and gender-matched volunteers w ere used as controls. We found that patients with NI-CINA had increased fre quency of antinuclear antibodies (ANA) compared to controls (33.1 vs. 9.5%, p = 0.0025), and that ANA positivity inversely correlated with the number of circulating neutrophils (r = -0.2765, p < 0.0001). Speckled pattern of r eactivity was seen in 84.6% of ANA-positive patients, and diffuse pattern i n the remaining 15.4%. Patients had also increased levels of circulating im mune complexes compared to controls (3.30 <plus/minus> 2.41 vs. 1.70 +/- 1. 19 mug/ml, p = 0.0042), which inversely correlated with the number of circu lating neutrophils ir = -0.2405, p = 0.0154) but not with the titer of ANA positivity. No significant differences were found between the patients and the normal controls in the frequency of positive tests for antibodies to ds DNA, Sm, nRNP, SSA, SSB and Scl-70 antigens, or for parietal cell antibodie s, anti-neutrophil cytoplasmic antibodies (ANCA), anti-cardiolipin and anti -thyroid antibodies. Serum levels of rheumatoid factor, C-reactive protein (CRP) and complement factors C3 and C4 ranged within normal limits in the p atients studied, but a highly significant correlation was noted between the levels of CRP and ANA positivity (r = 0.3936, p <0.0001). These findings a re suggestive of a chronic inflammation in NI-CINA patients which provides the antigenic stimulus for ANA production, and they further support our pre viously reported suggestion for the possible involvement of such a low-grad e chronic inflammatory process in the pathogenesis of neutropenia in the af fected subjects. Copyright <(c)> 2001 S.Karger AG. Basel.