Table 4 Summary of the results of seronegative and seropositive pSS in published studies

Veli Yazisiz [7]

Turkey

seropositive group (317):

Anti-Ro+/Anti-La+/ANA+/RF+.

seronegative group (58):

negative for all four autoantibodies

Retrospective

No statistically significant differences in terms of patient age, age at diagnosis, sex distribution, clinical features, and laboratory findings were found between seronegative and seropositive pSS. The frequency of hypergammaglobulinemia was higher in seropositive pSS.

G. Cafaro [19]

Italy

Patients with anti-Ro and positive SGB were included.

SSB- group (319)

SSB + group (281)

Retrospective

Anti-SSB positive patients were younger at disease diagnosis and had a longer disease duration, had a higher prevalence of hypergammaglobulinaemia and circulating rheumatoid factor and of lymphoproliferative disorders in comparison to seronegative group.

Jowy Tani [14]

Taiwan, China

Seronegative group [10]:

SSA- and SSB-

seropositive group(28):

SSA + or SSB+

Retrospective

Thermal QST showed more prominent abnormalities in seronegative pSS compared to seropositive pSS, while seronegative pSS showed much less prominent motor axonal changes and no significant sensory axonal changes.

Y. Park [17]

Korea

SSA + group (326),

SSA- group (29)

Retrospective

The anti-SSA negative group showed less rheumatoid factor positivity, leucopenia, hypergammaglobulinemia, lower serum β2-microglobulin level, more anti-centromere antibody positivity, higher score in dryness domain of EULAR SS patient-reported index and more positivity for peripheral nervous system domain in EULAR SS disease activity index and loss of teeth than patients who were anti-Ro/SSA positive.

Ewa Kontny [18]

Poland

Group 1 [15]: SSA- and SSB-

Group 2 (27): SSA + only

Group 3 (39): SSA + and SSB+

Retrospective

Patients of groups 2 and 3 developed disease symptoms at younger age, and more often had positive Schirmer’s test and skin lesions, higher frequency of autoantibodies other than anti-SSA and anti-SSB, higher serum concentrations of APRIL than those of group 1.

Luca Quartuccio [16]

Italy

seronegative group (206):

SSA-and SSB-

seropositive group (342):

SSA + and/or SSB+

Retrospective

Variables statistically associated with seropositive pSS were younger age at diagnosis, glandular swelling, purpura, leucopoenia, lymphoma, low C3, low C4, hypergammaglobulinemia, ANA, rheumatoid factor, and serum cryoglobulins. Seronegative pSS appears to be characterized by a lower risk of lymphoma and by a lower level of B-cell expansion.

Barbara

M. Segal [15]

America

Seropositive group (68):

SSA + or SSB+.

Seronegative group (40):

SSA- and SSB-.

Retrospective

Chronic pain, defined as daily pain for > 3 months, was reported by 65% of seropositive and 75% of seronegative patients. Pain severity was greater and physical function was reduced in the seronegative patients. Prevalence of neuropathic pain, depression, anxiety, and disability was similar between groups.