Background Hyperglobulinemia is a frequent serological abnormality in primary Sjögren's Syndrome (pSS) and might cause hyperviscosity. However a classic hyperviscosity syndrome (HVS) is rarely seen in these patients.
Objectives To compare the clinical and serological profile among three groups of pSS patients: 1) with HVS, 2) with high serum viscosity without HVS and 3) with normal viscosity.
Methods We included four pSS patients with HVS and 62 randomly patients with pSS according to the AECG criteria. HVS was defined as the presence of bleeding diathesis, visual abnormalities and neurologic deficits in the presence of a high serum viscosity (>4 c.p). High viscosity was defined as a serum viscosity >1.9 c.p. The ever presence of glandular (ocular, oral, parotid enlargement), extraglandular (splenomegaly, lymphadenopathy, non-erosive arthritis, myositis, Raynaud, skin vasculitis, pulmonary involvement, renal involvement, gastrointestinal involvement, neutropenia <1000, thrombocytopenia <100000, lymphopenia<10000 and leucopenia<3500) and serologic features (RF, ANA, ant-Ro and anti-La) were registered from the medical charts. We scored the ESSDAI activity index at the last visit. We used X2 and U-Mann Whitney tests.
Results Patients were predominantly females (95%) with a median age of 54 years and median disease duration of 9 years (0-42). Thirty-four patients (51.5%) had high viscosity, including the 4 patients with HVS. All the HVS cases were diagnosed concomitantly with the onset of SS. HVS patients have higher titers of IgG (6100 vs. 1547, p<0.001), IgM (1715 vs. 175, p<0.001), IgA (1330 vs. 318, p<0.001) and serum viscosity (14 vs. 1.9 c.p., p<0.001) than patients without HVS (n=61). In addition they had more vasculitis (50% vs. 8.3% p=0.05), neutropenia (100% vs. 6.7%, p<0.001,) lymphopenia (75% vs. 23.3% p=0.05), leucopenia (75% vs. 11.7%, p=0.01), splenomegaly (50% vs. 5%, p=0.02) and received more frequently prednisone (100% vs. 43%, p=0.04) and azathioprine (100% vs. 16.7%, p=0.002). The high viscosity group had a median serum viscosity of 2.2 c.p (range 2-3). This group had increased IgG, IgM and IgA levels, (p<0.01), a higher median ESSDAI (2 vs. 1, p<0.001) score and more vasculitis (16.7% vs. 0%, p=0.05) when compared with patients with normal viscosity.
Conclusions HVS in SS patients is associated with hematologic features, vasculitis and splenomegaly. The presence of vasculitis should alert about the coexistence of high viscosity values.
Acknowledgements Grant CB SEP/CONACYT
Disclosure of Interest None declared