To date, little research has been done on the hematologic abnormalities in patients with primary Sj-gren’s syndrome (pSS) and their significance in the disease. The first relevant study was published in 1965, in which Bloch made a detailed analysis of blood manifestations, serum protein concentrations, autoantibodies and immunoelectrophoresis in patients with dry syndrome (Sj-gren’s syndrome, SS). And it was not until nearly 30 years later that a second small series (27 patients) was reported, focusing on the hematologic manifestations of pSS. In the last decade, there has been a gradual increase in related reports from home and abroad, providing a strong basis for studying the pathogenesis, diagnostic criteria, and diagnosis and treatment of SS. pSS patients can present with a variety of hematologic abnormalities, including anemia, hematocrit, hypergammaglobulinemia, and monoclonal immunoglobulinemia. In addition, SS patients are also prone to malignant lymphoproliferative disorders, mainly non-Hodgkin’s lymphoma (NHL) of B-cell origin. Anemia According to most of the literature, about a quarter of SS patients have anemia, mostly mild orthocytic orthochromic anemia. Orthocytic orthochromic anemia, only 3 cases (4%) were microcytic anemia and 2 cases (3%) were macrocytic anemia. The etiology of 21 patients with anemia was clear, such as gastrointestinal bleeding, chronic atrophic gastritis, lymphoproliferative disorders, and hemolytic anemia, but no other possible causes of anemia other than pSS were found in the other 55 patients. In addition, other types of anemia, such as hemolytic anemia, remittent anemia, pernicious anemia, myelodysplastic syndrome (refractory anemia with ringed iron granulocytes), and pure red remittent anemia, can also occur in pSS patients, but are very rare. Those with SS with anemia are more likely to have renal involvement, cutaneous vasculitis, peripheral neuropathy, antinuclear antibodies, anti-SSA, anti-SSB, rheumatoid factor, cryoglobulinemia, and hypocomplementemia than those without anemia. Leukopenia The literature reports that 30% of SS patients have below normal leukocytes and 25% of SS patients have eosinophilia or lymphocytosis. the Ramos-Casals study found leukopenia (white blood cell count <4×109/L) in 59 of 380 (16%) pSS patients and severe leukopenia (<2×109/L) in only 1 case (0.2 %). This is similar to the previous literature series that reported a 17% prevalence of leukopenia in a total of 877 patients. Univariate analysis showed a higher incidence of peripheral neuropathy, anti-SSA, anti-SSB, rheumatoid factor, cryoglobulinemia and hypocomplementemia in those with pSS with leukopenia compared to those without leukopenia, but multifactorial analysis found only anti-SSA and rheumatoid factor to be meaningful independent variables. CD4+ T lymphocytopenia CD4+ T lymphocytopenia, mainly manifested as a reduction in the CD4+CD45RA+ subpopulation, is not uncommon in patients with pSS, with a reported incidence of approximately 5%. Idiopathic CD4+ T lymphocytopenia occurs only in anti-SSA-positive pSS patients, thus predisposing this subgroup of SS patients to NHL. Thrombocytopenia Ramos-Casals found that 48 of 380 (13%) pSS patients had thrombocytopenia (platelet count <150×109/L), most of which were mild and 11 (3%) had thrombocytopenia. The majority were mild, 11 (3%) were moderate (<100×109/L), and only 3 (0.4%) were severe (<50×109/L). Univariate analysis revealed that those with pSS with reduced platelets were more likely to have renal involvement and anti-SSB positivity than those with normal platelets, and multifactorial analysis also confirmed that both were meaningful independent variables. In contrast, the prevalence of thrombocytopenia in a total of 643 patients previously reported in the literature was 11%. Monoclonal immunoglobulinopathy 50% of SS patients have reduced albumin and increased polyclonal globulin. All three major immunoglobulins may be increased, most notably IgG, but also, less frequently and to a lesser extent, IgA and IgM. Macroglobulin or mixed cryoglobulinemia is less common, and these patients often have a hyperviscosity syndrome. Lymphoproliferative diseases Among autoimmune diseases, SS has the highest incidence of malignant lymphoproliferative diseases, and therefore SS is considered a crossroads between autoimmune and lymphoproliferative diseases. In the latest meta-analysis of a large series of studies on the incidence of NHL in autoimmune diseases, which included 8700 cases of SLE (6 studies), 95104 cases of rheumatoid arthritis (9 studies) and 1300 cases of pSS (5 studies), the highest incidence of NHL in pSS was found to be 18.8%, compared with 7.4% in SLE and 3.9% in rheumatoid arthritis was only 3.9%. The incidence and risk of lymphoma varied among studies due to the different diagnostic criteria on which they were based and the duration of follow-up. Domestic observations suggest that the incidence of SS combined with lymphoma is lower in China than abroad. In addition, the length of time from the diagnosis of SS to the development of NHL varies. Most of the patients with SS in China have a combination of extra-glandular systemic damage, so it is necessary to closely follow up the possibility of its evolution into lymphoma. The presence of persistent enlargement of parotid glands, spleen, and lymph nodes with cough, dyspnea, unilateral pulmonary masses, and persistent Raynaud's phenomenon should alert for the development of lymphoma. As mentioned above, laboratory tests for monoclonal hyperr-globulinemia, macroglobulinemia, mixed cryoglobulinemia, decreased IgM, elevated B2 microglobulin, and negative RF also suggest the possibility of underlying lymphoma. Other hematologic malignancies Multiple myeloma is rare in SS. There have been isolated cases of extramedullary IgG and IgA plasmacytoma of the major salivary glands and primary junctional plasmacytoma. Other hematologic malignancies such as T-cell granulomatous lymphocytic leukemia, angioimmunoblastomatous lymphadenopathy with abnormal proteinemia, and multicentric Castleman disease are also seen in patients with SS.