Proinflammatory phenotype of B10 and B10pro cells elicited by TNF-α in rheumatoid arthritis.

OBJECTIVES: B10 and B10pro cells suppress immune responses via secreting interleukin (IL)-10. However, their regulators and underlying mechanisms, especially in human autoimmune diseases, are elusive. This study aimed to address these questions in rheumatoid arthritis (RA), one of the most common highly disabling autoimmune diseases. METHODS: The frequencies and functions of B10 and B10pro cells in healthy individuals and patients with RA were first analysed. The effects of proinflammatory cytokines, particularly tumour necrosis factor (TNF)-α on the quantity, stability and pathogenic phenotype of these cells, were then assessed in patients with RA before and after anti-TNF therapy. The underlying mechanisms were further investigated by scRNA-seq database reanalysis, transcriptome sequencing, TNF-α-/- and B cell-specific SHIP-1-/- mouse disease model studies. RESULTS: TNF-α was a key determinant for B10 cells. TNF-α elicited the proinflammatory feature of B10 and B10pro cells by downregulating IL-10, and upregulating interferon-γ and IL-17A. In patients with RA, B10 and B10pro cells were impaired with exacerbated proinflammatory phenotype, while anti-TNF therapy potently restored their frequencies and immunosuppressive functions, consistent with the increased B10 cells in TNF-α-/- mice. Mechanistically, TNF-α diminished B10 and B10pro cells by inhibiting their glycolysis and proliferation. TNF-α also regulated the phosphatidylinositol phosphate signalling of B10 and B10pro cells and dampened the expression of SHIP-1, a dominant phosphatidylinositol phosphatase regulator of these cells. CONCLUSIONS: TNF-α provoked the proinflammatory phenotype of B10 and B10pro cells by disturbing SHIP-1 in RA, contributing to the disease development. Reinstating the immunosuppressive property of B10 and B10pro cells might represent novel therapeutic approaches for RA.

Human umbilical cord mesenchymal stem cells confer potent immunosuppressive effects in Sjögren's syndrome by inducing regulatory T cells.

BACKGROUND: Primary Sjögren's syndrome (SS) is a lymphoproliferative disease with a chronic autoimmune disorder characterized by mononuclear cell (MNC) infiltration of notably the lacrimal and salivary glands. As mesenchymal stem cells (MSCs) regulate series of immunological responses partially by regulating proportion of CD4+ T cells and inducing an immunosuppressive local milieu, umbilical cord MSCs (UC-MSCs) are being considered as a novel source for cell-based therapies against primary SS. This study aimed to investigate the feasibility of UC-MSCs in treatment of SS and to explore the possible mechanism(s) with the special emphasis on regulatory T cells (Tregs). METHODS: Potent immunosuppressive effects of human UC-MSCs on SS were explored in vivo and in vitro. To study the effects of human UC-MSCs on the development and progression of SS, human UC-MSCs were administered before disease onset (preventive protocol) and after disease occurrence (therapeutic protocol) in non-obese diabetic (NOD) mice. In human study, the effect of human UC-MSCs on T cells from SS patients was studied. RESULTS: In both protocols, the histopathology of submandibular and sublingual salivary glands showed decreased inflammatory infiltrates. In vitro, human UC-MSCs exhibited potent suppressive effects on responses of MNCs in NOD mice and T cells in SS patients. Such inhibitory effects were coupled with decreased production of proinflammtory cytokines interferon-γ, interleukin (IL)-6, tumor necrosis factor-α and increased production of IL-10 (n = 10, p < .01). The frequency of CD4+Foxp3+T cells in the spleen of NOD recipients was elevated (n = 6, p < .05). CONCLUSION: Human UC-MSCs are capable of inducing CD4+Foxp3+ T cells in both NOD mice and human in vitro. Human UC-MSCs effectively interfere with the autoimmune attack in the course of SS by inducing an in vivo state of T cell unresponsiveness and the upregulation of Tregs.

Bone marrow mesenchymal stem cells improve bone erosion in collagen-induced arthritis by inhibiting osteoclasia-related factors and differentiating into chondrocytes.

BACKGROUND: Rheumatoid arthritis (RA) is characterized by joint inflammation and damage to the cartilage and bone in collagen-induced arthritis (CIA). Mesenchymal stem cells (MSCs) can improve articular symptoms and reduce bone erosion in CIA rats; however, the underlying mechanism remains unknown. This study aimed to investigate the mechanism underlying MSC-induced improvement of bone destruction in CIA. METHODS: Wistar rats were divided into a normal group, CIA control group, MTX intervention group, and BMSC intervention group, each comprising 8 rats. Serum RANKL, OPG, and CXCL10 levels of all groups were determined via flow cytometry after 42 days of interventions. RANKL, OPG, TRAF6, CXCL10, and CXCR3 were detected on the synovial membrane via immunohistochemistry, and their relative mRNA levels were determined via RT-PCR analysis. BMSCs were labeled with GFP and administered to CIA rats via the tail vein. At different time points, the distribution of implanted GFP-MSCs in synovial tissues was observed using a fluorescence microscope, and the potential of GFP-MSCs to differentiate into chondrocytes was assessed via immunofluorescence analysis. RESULTS: BMSC transplantation improved joint inflammation and inhibited bone destruction in CIA rats. BMSCs inhibited the expression of serum CXCL10 and CXCL10 and CXCR3 expression at the synovial membrane. Moreover, protein and mRNA expression analyses revealed that BMSCs potentially regulated RANKL/OPG expression levels in the serum and synovial tissue. Upon implantation into CIA rats, GFP-MSCs were traced in the joints. GFP-positive cells were observed in the cartilage tissue from day 11 and until 42 days after transplantation. Anti-type II collagen/GFP double-positive cells were observed in the articular cartilage (especially damaged cartilage) upon immunofluorescence staining of anti-type II collagen. CONCLUSIONS: BMSCs improve bone destruction in CIA by inhibiting the CXCL10/CXCR3 chemotactic axis, regulating the RANKL/OPG ratio, and directly differentiating into chondrocytes.

Fas- and Mitochondria-Mediated Signaling Pathway Involved in Osteoblast Apoptosis Induced by AlCl3.

Aluminum (Al) is known to induce apoptosis of osteoblasts (OBs). However, the mechanism is not yet established. To investigate the apoptotic mechanism of OBs induced by aluminum trichloride (AlCl3), the primary OBs from the craniums of fetal Wistar rats were exposed to 0 mg/mL (control group, CG), 0.06 mg/mL (low-dose group, LG), 0.12 mg/mL (mid-dose group, MG), and 0.24 mg/mL (high-dose group, HG) AlCl3 for 24 h, respectively. We observed that AlCl3 induced OB apoptosis with the appearance of apoptotic morphology and increase of apoptosis rate. Additionally, AlCl3 treatment activated mitochondrial-mediated signaling pathway, accompanied by mitochondrial membrane potential (ΔΨm) depolarization, release of cytochrome c from the mitochondria to the cytoplasm, as well as survival signal-related factor caspase-9 and caspase-3 activation. AlCl3 exposure also activated Fas/Fas ligand signaling pathway, presented as Fas, Fas ligand, and Fas-associated death domain expression enhancement and caspase-8 activation, as well as the hydrolysis of Bid to truncated Bid, suggesting that the Fas-mediated signaling pathway might aggravate mitochondria-mediated OB apoptosis through hydrolyzing Bid. Furthermore, AlCl3 exposure inhibited Bcl-2 protein expression and increased the expressions of Bax, Bak, and Bim in varying degrees. These results indicated that AlCl3 exposure induced OB apoptosis through activating Fas- and mitochondria-mediated signaling pathway and disrupted B-cell lymphoma-2 family proteins.

Impairment of Granzyme B-Producing Regulatory B Cells Correlates with Exacerbated Rheumatoid Arthritis.

Hyperactivated B cells have been demonstrated the contribution to the development of rheumatoid arthritis (RA). While the recognition of the negative regulatory function of B cells further promoted our understanding of their pathogenic role in RA. Recently, a new population of granzyme B (GrB)-producing B cells was identified, which was proved to be involved in cancer and infectious diseases. However, their characteristics and roles in RA remain to be elucidated. In the present study, we aim to further characterize whether B cells could produce GrB and reveal their potential role in the pathogenesis of RA. Here, we further demonstrated peripheral blood B cells from healthy individuals could produce and secrete GrB, which could be enhanced by IL-21 and/or anti-B-cell receptor stimulation. These cells could negatively regulate Th1 and Th17 cells partly via downregulating TCR zeta chain and inducing T cell apoptosis, which might be termed as GrB-producing regulatory B cells (Bregs). These GrB-producing Bregs were significantly decreased under RA circumstance concomitant of lower levels of IL-21 receptor, with impaired regulatory functions on Th1 and Th17 cells. Moreover, the frequencies of these cells were negatively correlated with RA patient disease activity and clinical features. After effective therapy with disease remission in RA, these GrB-producing Bregs could be recovered. Therefore, our data revealed that B cells could produce GrB with immunosuppressive functions, and the impairment of this Breg subset was correlated with RA pathogenesis.

Pathogenic conversion of regulatory B10 cells into osteoclast-priming cells in rheumatoid arthritis.

Regulatory B10 cells were functionally impaired in rheumatoid arthritis (RA), yet the mechanisms were unclear. B cells are recently recognized as important participants in osteoclastogenesis by producing RANKL. In this study, we investigated whether regulatory B10 cells could convert into RANKL-producing cells, thus impairing their immunosuppressive functions in RA and exacerbating the disease progression. Our results showed that human regulatory B10 cells could ectopically express RANKL. Under RA circumstance, RANKL-producing B10 cells expanded dramatically, partially induced by TNF-α. The frequencies of these cells were positively correlated with RA patient disease activities and tender joint counts, but negatively correlated with the frequencies of regulatory B10 cells. Strikingly, RANKL-producing B10 cells from RA patients, but not healthy individuals significantly promoted osteoclast differentiation and bone erosion in a paracrine and cell-cell contact-dependent manner. Moreover, these pathogenic RANKL-producing B10 cells declined while regulatory IL-10-producing B10 cells increased in RA patients with disease remission after therapy. Collectively, these results showed that in RA, regulatory B10 cells demonstrated the potential of converting into RANKL-producing cells, thus exacerbating osteoclast formation, bone destruction and disease progression. Modulating the status of B10 cells might provide novel therapeutic strategies for RA.

Tunable Oleo-Furan Surfactants by Acylation of Renewable Furans.

An important advance in fluid surface control was the amphiphilic surfactant composed of coupled molecular structures (i.e., hydrophilic and hydrophobic) to reduce surface tension between two distinct fluid phases. However, implementation of simple surfactants has been hindered by the broad range of applications in water containing alkaline earth metals (i.e., hard water), which disrupt surfactant function and require extensive use of undesirable and expensive chelating additives. Here we show that sugar-derived furans can be linked with triglyceride-derived fatty acid chains via Friedel-Crafts acylation within single layer (SPP) zeolite catalysts. These alkylfuran surfactants independently suppress the effects of hard water while simultaneously permitting broad tunability of size, structure, and function, which can be optimized for superior capability for forming micelles and solubilizing in water.

AlCl3 induces lymphocyte apoptosis in rats through the mitochondria-caspase dependent pathway.

To investigate apoptosis mechanisms in lymphocytes induced by aluminum trichloride (AlCl3) through the mitochondria-caspase dependent pathway, the spleen lymphocytes of rats were cultured with RPMI-1640 medium and exposed to AlCl3·6H2O in the final concentrations of 0 (control group, CG), 0.3 (low-dose group, LG), 0.6 (mid-dose group, MG), and 1.2 (high-dose group, HG) mmol·L(-1) for 24 h, respectively. Mitochondrial transmembrane potential (ΔΨm), cytochrome C (Cyt C) protein expression in cytoplasm, Caspase-3 and Caspase-9 activity, Bcl-2, Bax, Caspase-3 and Caspase-9 mRNA expressions, DNA ladder and lymphocytes apoptosis index were detected. The results showed that Cyt C protein expression in cytoplasm, Caspase-3 and Caspase-9 activity, Bcl-2, Bax, Caspase-3 and Caspase-9 mRNA expressions, the ratio of Bcl-2 and Bax mRNA expression, lymphocytes apoptosis index increased, while ΔΨm decreased in the AlCl3-treated groups compared with those in CG. The results indicate that AlCl3 induces lymphocyte apoptosis in rats through the mitochondria-caspase dependent pathway.

NE strengthens the immunosuppression induced by AlCl3 through ß2-AR/cAMP pathway in cultured rat peritoneal macrophages.

To investigate the effect of noradrenaline (NE) on the immunosuppression induced by aluminum trichloride (AlCl3), the peritoneal macrophages were cultured with RPMI-1640 medium containing 0.97 mM AlCl3 (1/10 IC50). NE was added to the medium at the final concentrations of 0 (control group, N-C), 0.1 (low-dose group, N-L), 1 (mid-dose group, N-M), and 10 (high-dose group, N-H) nM, respectively. No addition of both AlCl3 and NE serviced as blank group (D-C). Chemotaxis, adhesion, phagocytosis, tumor necrosis factor α (TNF-α) secretion, cyclic adenosine monophosphate (cAMP) content, ß2 adrenergic receptors (ß2-AR) density, and messenger RNA (mRNA) expression of macrophages were detected. The results showed that AlCl3 reduced the chemotaxis, adhesion, phagocytosis, and TNF-α secretion and increased the cAMP content, ß2-AR density, and mRNA expression of peritoneal macrophages. Meanwhile, the chemotaxis, adhesion, phagocytosis, TNF-α secretion, ß2-AR density, and mRNA expression were reduced while the cAMP content was increased in NE-treated groups than those in N-C group. The results indicated that NE strengthens the immunosuppression induced by AlCl3 in cultured rat peritoneal macrophages through the ß2-AR/cAMP pathway.

Aluminum chloride- and norepinephrine-induced immunotoxicity on splenic lymphocytes by activating ß2-AR/cAMP/PKA/NF-κB signal pathway in rats.

We found in our previous research that aluminum (Al) exposure induced immunotoxicity on spleen and increased norepinephrine (NE) content in serum from rats. However, it is unclear how NE is involved in the AlCl3 immunotoxicity on rats. Therefore, this experiment was designed to explore the mechanism of AlCl3 and NE-induced immunotoxicity on the splenic lymphocytes. Eighty male Wistar rats were orally exposed to AlCl3 (0, 64, 128, and 256 mg/kg BW) through drinking water for 120 days. Al contents in brain and spleen; NE contents in serum and in the hypothalamus; ß2-AR density; cAMP content; ß2-AR, PKA, and NF-κB mRNA expression levels; and protein expressions of PKA and nuclear NF-κB in splenic lymphocytes of AlCl3-treated rats were examined. The results showed that AlCl3 increased NE content in serum, the ß2-AR density, the ß2-AR and PKA (C-subunits) mRNA expression levels, cAMP content and the PKA (C-subunits) protein expression levels in lymphocytes, whereas, decreased NE content in the hypothalamus, the NF-κB (p65) mRNA expression level and nuclear NF-κB (p65) protein expression level in lymphocytes. These results indicated that the accumulated AlCl3 in spleen and the increased NE in serum induced the immunotoxicity on splenic lymphocytes by activating ß2-AR/cAMP/PKA/NF-κB signal pathway in rats.

Epidemiology of eight common rheumatic diseases in China: a large-scale cross-sectional survey in Beijing.

OBJECTIVE: To investigate the prevalence of eight common rheumatic diseases in a large Chinese population. METHODS: A population-based epidemiological investigation of the prevalence of eight common rheumatic diseases in a suburb of Beijing was conducted in 14 642 individuals. A community-based survey was carried out using a screening questionnaire. Positive responders were included in a clinical and laboratory examination. Diagnosis was based on the criteria of ACR or those used widely in literature. RESULTS: A total of 10 556 inhabitants were interviewed. Forty-three cases of RA were identified with an age-adjusted prevalence of 0.28% (95% CI 0.19%, 0.41%). Gout was diagnosed with a crude prevalence of 0.09% (95% CI 0.05%, 0.17%). Psoriasis was reported in 28 individuals with a prevalence of 0.27% (95% CI 0.18%, 0.38%). This included two cases diagnosed with PsA, resulting in a prevalence of 7.14% (95% CI 0.88%, 23.5%) in psoriasis patients and 0.02% (95% CI 0%, 0.07%) in the general population. Three individuals were identified with SLE, with a prevalence of 0.03% (95% CI 0%, 0.06%). One individual was identified with SSc and the calculated prevalence was 0.01% (95% CI 0%, 0.05%). One case of Behçet's disease was identified, giving a prevalence of 0.01% (95% CI 0%, 0.05%). CONCLUSION: This large-scale epidemiological survey provides an estimate of the burden of rheumatic diseases in China.

Hyperuricemia accompanied with changes in the retinal microcirculation in a Chinese high-risk population for diabetes.

OBJECTIVE: To investigate the association of retinal vascular calibers with hyperuricemia in a middle-aged and elderly population. METHODS: A cross-sectional design was applied in this study and 869 participants aged =40 years from a high-risk group for diabetes were recruited. All participants received the anthropometrical measurements and laboratory tests. Retinal arteriolar and venular caliber of the participants were measured with a semi-automated system. Hyperuricemia was defined as a serum uric acid level >420 µmol/L in men and >360 µmol/L in women. Linear regression models were used to assess the association of hyperuricemia with retinal vascular calibers. These models were additionally adjusted for age, central obesity, hypertension, dyslipidemia, weekly activity, smoking status, and education. RESULTS: Among the 869 participants, 133 (15.3%) suffered from hyperuricemia. The crude mean serum uric acid level was 312.3 µmol/L (Standard Deviation 79.5); mean concentration was 355.0 µmol/L (SD 75.5) in male participants, and 288.0 µmol/L (SD 71.1) in female participants (age-adjusted difference 58.1 µmol/L, 95% Confidence Internal 48.5, 67.6). After adjusting for additional covariates, male participants with hyperuricemia had 3.77 µm (95% CI -0.46, 8.00) smaller arteriolar caliber and 6.20 µm (95% CI 0.36, 12.04) larger venule than those without hyperuricemia; the corresponding numbers among female participants were 1.57 µm (95% CI -1.07, 4.21) for retinal arteriolar caliber and 2.28 µm (95% CI -1.72, 6.27) for retinal venular caliber. CONCLUSION: Hyperuricemia was associated with smaller retinal arteriolar caliber and larger venular caliber mainly in male participants in this study.

[Possible mechanisms of peripheral elevated CD8+ IL-17+ T cells in rheumatoid arthritis].

OBJECTIVE: To identify interleukin-17 (IL-17 )-producing CD8 positive T cells from patients with rheumatoid arthritis (RA), and investigate its cytokines as well as their correlations. METHODS: Peripheral blood got from 39 RA patients and 40 healthy donors. Flow cytometry was used to analyze the subsets of T cells in peripheral blood from these 39 RA patients and 27 healthy donors. 11-17, IL-6, and IL-23 levels in sera of all these people were tested by ELISA. RESULTS: The median of CD8 IL-17+ T cells from RA patients was 2.7% (95% confidence internal was 1.55%-3.74%); the median of these cells from healthy controls was 1.61% (95% confidence internal was 1.25%-2.61%). CD8+ IL-17+ T cells elevated significantly in RA(P < 0.05). As the production of CD8+ IL-17+ T cells, the IL-17 levels in sera of RA patients and healthy controls were (429 +/- 502) ng/L and (13 +/- 30) ng/L respectively. The IL-17 level in RA is higher than that in healthy people (P < 0.01). Meanwhile, to constitute CD8+ IL-17+ T cell polarizing condition, IL-23 and IL-6 in sera of RA were (157.83 +/- 27.07) ng/L and (32.67 +/- 34.50) x ng/L individually. These two cytokines in healthy controls were (21.97 +/- 3.52) ng/L and (1.82 +/- 1.51) ng/L severally. IL-6 and IL-23 increased clearly in peripheral blood of RA patients as compared with healthy donors (P < 0.01). CONCLUSIONS: This study suggested that elevated CD8+ IL-17+ T cells which involved in IL-17 secretion may depend on increased IL-6 and IL-23 in peripheral blood of rheumatoid arthritis.

[Therapeutic effect and impact on cytokine production by methotrexate in rheumatoid arthritis].

OBJECTIVE: To examine the clinical benefit and impact on cytokine production by methotrexate in rheumatoid arthritis. METHODS: Thirty patients with RA were treated with oral methotrexate (mean, 15 mg per week) as monotherapy for 24 weeks. Clinical assessment using the American College of Rheumatology (ACR) criteria for improvement was performed at baseline and at the end of 2, 4, 8, 12 and 24 weeks. The pro-inflammation cytokine TNF-alpha, INF-gamma,IL-1beta, IL-6 and anti-inflammation cytokine IL-10 were measured in RA sera at baseline and after 24 weeks of therapy. RESULTS: There was remarkable improvement in disease activity following the MTX treatment. At the end of 24 weeks, the percent age of ACR20 was 70% (21/30), ACR50 30% (9/30) and ACR70 10% (3/30). The levels of IL-6 (46.83+/-35.81 vs. 20.92+/-17.98, P=0.001), TNF-alpha (162.52+/-107.63 vs. 18.32+/-14.36, P=0.026) and INF-gamma (67.79+/-43.76 vs. 35.78+/-27.51, P=0.004) were significantly higher than those of the health control at baseline, respectively. The levels of TNF-alpha (123.36+/-89.61,P=0.018), INF-gamma (41.53+/-13.49, P=0.015), IL-1beta (7.47+/-7.33, P=0.026), IL-6 (26.01+/-25.64, P=0.025) were significantly decreased after treatment with methotrexate. In contrast, IL-10 was remarkably increased (71.76+/-41.01, P=0.02). CONCLUSION: Methotrexate is effective in patients with rheumatoid arthritis. It can suppress the symptoms and joint damage. In addition, methotrexate treatment decreases the levels of pro-inflammatory cytokine, and increases the level of anti-inflammatory cytokine.

[The re-expression of p15(INK4B) gene in leukemia cells induced by in vitro DNA methyltransferase and histone deacetylase inhibition].

OBJECTIVE: To explore the possibility of re-expression of silenced p15(INK4B) gene in leukemia cells by 5-Aza-2'-deoxycytidine (CdR), a DNA methyltransferase inhibitor, and sodium butyrate (SB), a histone deacetylase inhibitor. METHODS: A myeloid leukemia cell line, KG1a and two primary cultured leukemia cells isolated from bone marrow of AML-M(2) and MDS-RAEB-T patients were chosen as the experimental target. The methylation pattern of p15(INK4B) gene was analyzed with restriction endonucleases combined with PCR technique. The expression level of mRNA and protein was detected by RT-PCR technique and Western blot. RESULTS: All detected leukemia cells showed a hypermethylated promoter region of p15(INK4B) gene with complete or partial loss of expression of mRNA and protein. Either CdR or SB induced weak expression of p15(INK4B) with a dose dependent effect. Combined low dose of CdR (0.5 micro mol/L) and SB (0.5 mmol/L) increased the expression level of p15(INK4B) significantly. The synergistic effect of the two drugs was significantly stronger than that of any drug of high dose alone. CONCLUSION: Hypermethylated and silenced p15(INK4B) gene could be re-expressed by synergy of CdR and SB.

Re-expression of p16 gene in the myeloma cell line U266 induced by synergy of sodium butyrate and 5-Aza-2'-deoxycytidine.

OBJECTIVE: To understand the synergic effect of histone deacetylase inhibitor sodium butyrate (SB) and demethylating agent 5-Aza-2'- deoxycytidine (5-Aza-CdR) on cell growth and to explore the possibility of re-expression of the hypermethylated and silenced p16 gene in the myeloma cell line U266. METHODS: U266 cells were cultured in RPMI 1640 in the presence of varied doses of SB and 5-Aza-CdR, and the growth curve was obtained by trypan-blue exclusion assay and cell count. The cell cycle was analyzed by flow cytometry and the expression level of mRNA and protein of p16 gene were detected by reverse transcriptase-PCR and Western blotting, respectively. RESULTS: The cell growth was arrested by treatment with 5-Aza-CdR alone or SB alone. Increased inhibition effect was shown in synergic treatment of SB and 5-Aza-CdR. The G(1) phase of cell cycle was arrested by 5-Aza-CdR combined with SB, which, however, did not occur when SB or 5-Aza-CdR was used alone. 5-Aza-CdR alone induced the expression of p16 gene in a concentration-dependent manner, whereas SB alone only induced its low-level expression. The expression level of both mRNA and protein of p16 gene was increased significantly by synergic application of SB and 5-Aza-CdR. CONCLUSION: Hypermethylated and silenced p16 gene in U266 cell line can be markedly reactivated by synergic treatment with demethylating agent 5-Aza-CdR and histone deacetylase inhibitor SB, and the cell growth can be inhibited and cell cycle arrested at G(1) phase.

[The clinical features and tumor cells characteristics of splenic marginal zone lymphoma].

OBJECTIVE: To deepen the understanding of splenic marginal zone lymphoma (SMZL) and improve the level of diagnosis and therapy. METHODS: A typical case of SMZL, a 61 year old female with lymphocytosis and splenomegaly found fortuitously, was reported. The pathologic, immunologic and genetic features of tumor cells in peripheral blood, bone marrow and spleen were studied with light microscopy, phase contrast microscopy, scanning electron microscopy, immunohistochemical method, flow cytometry, G chromosome banding technique and PCR for studying the pattern of IgH gene rearrangement. RESULTS: The spleen was large with uniform parenchyma and smooth surface. There were multiple small gray-white nodules on sections. Histologically, the neoplastic cells replaced the marginal and mantle zones with complete replacement of germinal centers in the white pulp. The neoplastic cells were predominantly of small to medium size with oval or slightly irregular nuclei. Lymph nodes in the splenic hilum were infiltrated by tumor cells. Immunophenotypic analysis demonstrated that the lymphocytes in the bone marrow expressed CD(20), HLA-DR, CD(45) RA and bcl-2. The monoclonal pattern of IgH gene rearrangement in peripheral blood and bone marrow was found to be the same as that in spleen. After splenectomy, COP chemotherapy and IFNalpha-2a were given and the abnormally increased lymphocytes decreased to normal level. Seven months later the monoclonal rearranged immunoglobulin heavy chain gene pattern changed to polyclonal pattern. CONCLUSION: Splenomegaly, lymphocytosis in peripheral blood and bone marrow without lymph node enlargement and leukocytosis are clinical characters of SMZL. Presence of monoclonal rearranged IgH gene is in favor of the diagnosis. Splenectomy should be done earlier in suspicious patients to avoid malignant transformation.