Ferritin synthesis by human T lymphocytes.

Mononuclear cells from peripheral blood of normal humans, unselected spleen cells from patients with Hodgkin's disease, and selected T and non-T lymphoid cells from normal peripheral blood and from the spleens of Hodgkin's disease patients were examined for de novo synthesis and secretion of ferritin. After precipitation of labeled lysates and supernatants from unseparated and selected T cells with antiserum to human liver ferritin, two bands were visible on sodium dodecyl sulfate-polyacrylimide gel analysis. The two bands were detected in molecular weight regions 19,000 and 21,000, which are thought to represent the L and H subunits of the ferritin molecule, respectively. The slower band (subunit H) was more radioactive than the faster band (subunit L). The H subunit is found in greater amounts in the serum of some tumor patients, but its cellular origin has not been established. The present findings indicate that cells of the immune system contribute to the synthesis and secretion of a ferritin molecule with a high proportion of H subunits.

Factor V C2 domain contains a major thrombin-binding site responsible for thrombin-catalyzed factor V activation.

Factor (F)V is converted into its active form, FVa, by limited proteolysis. Thrombin-catalyzed activation of FV is essential for its full cofactor activation. Previously, we reported that thrombin was bound to the C2 domain in the light chain of FVIII. As FV has a similar domain structure to FVIII, we focused on the FV C2 domain as a possible binding region for thrombin. Kinetic parameters, measured by surface plasmon resonance, revealed that the K(d) values of anhydro-thrombin for FV, FVa, and the FV C2 domain were 66, 240, and 670 nmol L(-1), respectively. FV activation was increased by approximately 9-fold by the addition of thrombin. In the presence of the FV C2 domain, this increase of the FV activation was inhibited. However, FV activation was not inhibited by the addition of the FVIII C2 domain. FV was cleaved into a 105-kDa heavy chain and a 71/74-kDa light chain by thrombin-catalyzed proteolysis at Arg709, Arg1018 and Arg1545. In the presence of the FV C2 domain, the cleavage was inhibited at all sites. Proteolysis was not affected by the addition of the FVIII C2 domain. These results indicated that the FV C2 domain contains a major binding site for thrombin and that this domain is necessary for the proteolysis at all cleavage sites. Furthermore, the present results also suggested that thrombin has an independent binding site for FV different from that for FVIII.

Heat stress-induced modulation of host defense against Toxoplasma gondii infection in mice.

This study examined the effects of burn injury on murine immune response against Toxoplasma gondii infection. Male C57BL/6 mice were divided into 3 groups: T. gondii infection (group T), burn injury (group B), and burn injury followed by T. gondii infection (group BT). The survival of group BT was significantly lower than those of group B and group T. Parasite abundance in the tissues was determined by quantitative competitive-polymerase chain reaction. Group BT exhibited significantly higher numbers of T. gondii than group T. Antibody production against T.g.HSP30 in group BT was significantly lower than that in group T, whereas no significant difference was observed in SAG1-specific antibody production. Delayed-type hypersensitivity (DTH) specific for 2,4-dinitrofluorobenzene (DNFB) of both group B and group BT was significantly lower than that of group T. One week after infection, serum interferon-gamma (IFN-gamma) and interleukin (IL)-10 levels in group BT were significantly lower, whereas serum IL-6 levels were significantly higher than in group T Serum TNF-alpha levels in both group T and group BT were elevated at 1 wk after infection, although there was no significant difference between them. Serum IFN-gamma, IL-10, and TNF-alpha levels in group B were not elevated during the experimental term. In conclusion, the impaired antigen-specific antibody production and DTH response, together with the modulated patterns of cytokine responses, seemed to be strongly involved in the development of burn-induced immunosuppression and the consequent increased susceptibility to T. gondii infection in mice.

Iron deposition in renal biopsy specimens from patients with kidney diseases.

This study was performed to investigate the correlation between clinical parameters and grading of iron deposition in renal biopsy specimens from 102 patients with various kidney diseases. Iron deposition in renal tissues was detected by Berlin blue staining. The extent of iron staining was semiquantitatively graded as negative (Fe(-)), grade 0, or positive (Fe(+)), including faint, grade 1; moderate, grade 2; or severe, grade 3, by light microscopy. Thirty-four of 102 patients (33%) showed positive iron staining. Fe(+) patients had various renal diseases, mainly consisting of 12 patients with immunoglobulin A nephropathy and 5 patients with benign nephrosclerosis. Mean arterial pressure (MAP), serum creatinine (sCr) levels, incidence of hematuria, and urinary N-acetylbeta-D-glucosaminidase (u-NAG) levels in Fe(+) patients were significantly greater than those in Fe(-) patients, and u-NAG levels correlated positively with the extent of iron deposition. Study patients were tentatively divided into two groups according to the extent of iron deposition: group A, patients with grades 2 and 3 staining, and group B, patients with grades 0 and 1 staining. In group A, MAP, sCr level, urinary protein excretion, and the incidence of hematuria were significantly greater than in group B. Our results suggest that the amount of iron deposition in renal tissue may contribute to the progression of chronic renal disease and may be an early and sensitive indicator of renal damage in certain renal diseases.

Ferritin correlates with C-reactive protein and acute phase serum amyloid A in synovial fluid, but not in serum.

OBJECTIVE: To evaluate ferritin concentration in serum and synovial fluid (SF) as a marker of activity of arthritis in comparison with C-reactive protein (CRP) and acute-phase serum amyloid A protein (A-SAA). METHODS: We determined the concentrations of ferritin, CRP and A-SAA in paired serum and SF in 34 rheumatoid arthritis (RA) and 21 osteoarthritis (OA) patients. The erythrocyte sedimentation rate (ESR) was also measured. RESULTS: The serum concentrations of ferritin, CRP and A-SAA were 93 +/- 76 (mean +/- SD) ng/ml, 4 +/- 5 mg/ml, 8 +/- 4 mg/ml in OA and 140 +/- 227, 59 +/- 34, 289 +/- 223 in RA, respectively. There was no significant difference in serum ferritin levels between OA and RA, and serum ferritin did not correlate with ESR, CRP or A-SAA. Both serum CRP and A-SAA levels were significantly higher in RA than in OA (p < 0.0001, p < 0.0001), and correlated with ESR in all arthritis (r = 0.658, p < 0.0001, r = 0.404, p < 0.01), respectively. Serum CRP levels correlated with A-SAA levels in serum (r = 0.727, p < 0.0001). In SF, the concentrations of ferritin, CRP and A-SAA in RA (421 +/- 307, 25 +/- 20 and 39 +/- 41) were significantly higher (p < 0.01, p < 0.0001, p < 0.001) than those in OA (202 +/- 220, 2 +/- 2 and 2 +/- 2), respectively. There were significant correlations among SF ferritin, CRP and A-SAA. CONCLUSION: Ferritin levels in SF but not in serum are significantly elevated in RA more than in OA, and ferritin correlated with CRP or A-SAA in SF, but not in serum. Higher levels of SF ferritin, as well as SF CRP and SF A-SAA, seem to reflect greater degrees of joints inflammation in RA and OA.

Sesquiterpenoids and iridoid glycosides from Valeriana fauriei.

A new guaiane sesquiterpenoid glycoside together with known sesquiterpenoids and iridoid glycosides have been isolated from the rhizomes and roots of Valeriana fauriei. The 13C NMR assignments of the isolated compounds are presented.

Elevation of serum ferritin levels as a marker for active systemic lupus erythematosus.

OBJECTIVE: To determine the clinical relevance of serum levels of ferritin in patients with systemic lupus erythematosus (SLE) vs. controls, we assessed the correlations between such levels and clinical disease activity, anti-DNA antibody titer, and serum levels of complement. METHODS: We evaluated 36 patients (3 males and 33 females) with SLE, including 21 patients with active disease. A total of 52 patients (3 males and 49 females) with rheumatoid arthritis (RA) served as controls. In a further study for reproducibility, 15 SLE and 21 RA patients were examined. Serum ferritin levels were measured by a 2-site radioimmunometric assay. Serum levels of C-reactive protein (CRP) were measured semiquantitatively by immunoprecipitation or quantitatively by laser immunonephelometry. Anti-DNA antibody was measured by the Farr assay. CH50 was measured by the hemolytic activity method. RESULTS: The SLE patients exhibited higher serum levels of ferritin and lower serum levels of CRP than the RA patients. Serum levels of ferritin at the active stage of SLE exceeded those at the inactive stage. The levels of serum ferritin in SLE were positively correlated with the anti-DNA antibody titer and negatively correlated with CH50 values. CONCLUSION: Serum levels of ferritin appear to provide a useful marker of disease activity in SLE patients.

Changes in immune function following surgery for esophageal carcinoma.

Changes in immune function due to surgical injury have been well-documented. Immunosuppression is one of the causes of infectious complications leading to organ dysfunction in critical illness. It is not known what kind of surgery in the daily clinical practice causes immunosuppression. Stress response and immune function following surgery for esophageal carcinoma, assuming a highly-stressed operation, were studied and then compared with the stress response and immune function following gastric surgery, a moderately-stressed procedure. Forty patients who underwent esophagectomy and 39 patients receiving gastric operation were studied. The concentrations of serum interleukin-6 (IL-6) were measured preoperatively, at 1, 2, and 6 h, and at 1, 3, and 10 d after operation. Total protein, serum albumin, rapid turnover protein, serum CRP, and cortisol were measured before operation and at 1, 3, 7, and 21 d after operation. ConA- and PHA-stimulated lymphocyte proliferation, IgA, IgG, and IgM were also measured preoperatively, and on 7 and 21 d following surgery. The patients were fed exclusively by total parenteral nutrition (TPN). A striking rise of IL-6 was observed, with a peak in both groups at 1 to 6 h following operation. The peak values were 419+/-30 pg/mL, which was approximately twice as high in the esophagectomy patients as in the gastrectomy patients (195+/-40 pg/mL). CRP and cortisol also increased after operation, and these increases were also significantly greater in the esophagectomy patients. ConA- and PHA-stimulated lymphocyte proliferation decreased significantly 7 d after esophagectomy (P<0.05), but was unchanged in the patients receiving gastrectomy. Suppression of cellular immunity correlated significantly with serum cortisol, and was preceded by a rise in serum IL-6. The IgA, IgG, and IgM levels, however, remained unchanged from their preoperative values throughout the study in both groups. Nutritional status in terms of serum protein, albumin, and rapid turnover protein, decreased postoperatively, but there was no difference between the two groups. It is, therefore, concluded that cell-mediated immunosuppression, preceded by a hyperinflammatory response, is an observable reaction in patients following esophageal surgery, but not in patients undergoing gastric surgery.

The number of CD10-positive glomerular epithelial cells reflects renal prognosis in IgA nephropathy patients.

BACKGROUND: The glomerular epithelial cells play an important role in glomerular filtration of the kidney. The disruption of these cells contributes to the development of glomerulosclerosis. The present study was performed to elucidate whether loss of the glomerular epithelial cells is associated with renal injury in patients with IgA nephropathy. PATIENTS AND METHODS: Thirty renal biopsy specimens from IgA nephropathy, 12 from minor glomerular abnormalities and 5 from normal controls were observed. The specimens from IgA nephropathy were divided into 2 groups: Group IgA-1, including 11 patients who had received a follow-up renal biopsy because of deterioration of renal function, and Group IgA-2, consisting of the remaining 19 patients without follow-up biopsy. Immunohistochemistry was performed using a monoclonal antibody against CD10 antigen that appears on mature epithelial cells of glomeruli. RESULTS: The average number of CD10-positive glomerular epithelial cells (GECs) was significantly lower in IgA nephropathy than in either minor glomerular abnormalities or the normal controls. In IgA nephropathy, there were significant correlations of the GECs with renal functions. The GECs were reduced along with the progression of histopathological damage. In group IgA-1, the GECs were significantly reduced at the second biopsy compared with the first biopsy, and significantly fewer in group IgA-1 than in group IgA-2 at the first biopsy. The GECs showed a significant correlation with renal prognosis during the follow-up period. CONCLUSIONS: The reduction of GECs was associated with renal dysfunction, histopathological damage and renal prognosis. The GECs may be a useful predictor of renal prognosis in IgA nephropathy.

Lobular form idiopathic glomerulonephritis with massive subendothelial and paramesangial immune deposits, a three-year follow-up case.

We report a patient with unusual glomerulonephritis. A 24-year-old Japanese female was hospitalized in October 1995 because of nephrotic syndrome. Lobular form glomerulonephritis with mesangial proliferation associated with massive wide-spread accumulation of slightly eosinophilic, periodic acid Schiff-positive amorphous materials in the luminal side of the capillary walls and paramesangial area was observed in the renal biopsy specimen. Immunofluorescent study revealed massive strong staining for IgM and C4 along the capillary walls and in the mesangium. Deposits of IgA, IgG, C3 and fibrinogen were also observed. Electron microscopy showed normal thickness of the capillary basement membrane and a large amount of subendothelial and paramesangial electron dense, finely granular deposits without fibrils or tubular structures. There were no clinical or laboratory findings of systemic diseases, such as systemic lupus erythematosus and cryoglobulinemia. Therefore, we believed that this case involved an unusual idiopathic glomerular disease with massive subendothelial and paramesangial immune deposits. Glomerulonephritis in this patient appeared to be resistant to treatment with corticosteroids and that this glomerulopathy may be a progressive disease as shown during the 3-year observation. Furthermore, our patient had idiopathic hyperprolactinemia and subclinical hypothyroidism. However, the relationship between glomerulonephritis and endocrinopathy in our patient is unknown.

Neuropeptide Y Y1 receptor polymorphism as a prognostic predictor in Japanese patients with IgA nephropathy.

BACKGROUND: Neuropeptide Y exhibits a vasoconstricting action and regulates systemic blood pressure as well as noradrenalin. There are 5 types of NPY receptors, Y1 - Y5, which were introduced by pharmacological differences. Recently, a single point mutation in the first intron of the NPY Y1 receptor (NPYY1R) was reported. SUBJECTS AND METHODS: In this study, we investigated the relationship between NPYY1R gene polymorphism and clinical characteristics in patients with IgA nephropathy using polymerase chain reaction and restriction fragment length polymorphism analysis. RESULTS: Distribution of the NPYY1R genotypes which were defined as YY, Yy and yy genotypes, did not differ between 60 normal control subjects and 68 patients with IgA nephropathy (15 : 36 : 9 versus 21 : 40 : 7, respectively). In IgA nephropathy patients, the incidence of hypertension and the rate of urinary protein excretion were slightly higher in the non-YY genotype than in the YY genotype group (23% versus 5% and 1.1 +/- 1.2 versus 0.6 +/- 0.4 g/24 h, p = 0.09 and p = 0.05, respectively). The reciprocal of the serum creatinine level was estimated to determine the deterioration in renal function during follow-up after the renal biopsy. The level was lower in the non-YY genotype than in the YY genotype group (-0.002 +/- 0.064 vs 0.033 +/- 0.053/month, respectively, p < 0.01). Multiple regression analysis for the reciprocal of the serum creatinine level revealed that the NPYY1R genotype was an effective variable (p < 0.01). CONCLUSION: In conclusion, we propose that the NPYY1R gene polymorphism may be a novel prognostic predictor in patients with IgA nephropathy.

Effect of a polymorphism of endothelial nitric oxide synthase gene in Japanese patients with IgA nephropathy.

BACKGROUND: Nitric oxide (NO) is synthesized by endothelial cell NO synthase (ecNOS) on vascular endothelium, and it plays a key role in the regulation of blood flow and pressure. A polymorphism of the ecNOS gene was recently shown to be associated with the development of cardiovascular disease. PATIENTS AND METHODS: We investigated the ecNOS gene polymorphism in 68 Japanese patients with IgA nephropathy (IgAN) and 134 normal controls. RESULTS: The genotype distributions were not different between the normal controls and the IgAN patients (ecNOS4b/b: ecNOS4b/a: ecNOS4a/a = 106:27:1 and 50:18:0, respectively). There was no significant difference in the renal histopathological grading between the patients with ecNOS4b/a and ecNOS4b/b. However, among the subgroup of patients whose duration of illness was two or more years, the advanced histopathological grading was more frequent in the patients with the ecNOS4b/a genotype (than in those with the ecNOS4b/b (p = 0.04)). The incidence of hypertension was also higher in the patients with the ecNOS4b/a genotype (50% in ecNOS4b/a versus 12% in ecNOS4b/b, p = 0.04). CONCLUSION: These results suggest that the ecNOS4b/a genotype (or ecNOS4a allele) of the ecNOS gene polymorphism may be involved in the progression of IgAN.

Serum transferrin receptor levels in patients with rheumatoid arthritis are correlated with indicators for anaemia.

To measure serum soluble transferrin receptor (s-TfR) levels in patients with rheumatoid arthritis (RA), sera were obtained from 50 Japanese RA patients and 20 healthy subjects. Both s-TfR and serum erythropoietin (EPO) levels were measured by enzyme-linked immunosorbent assay (ELISA). Routine laboratory tests were also performed, including peripheral blood analysis and determination of erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), rheumatoid factor (RF), serum iron levels, total iron-binding capacity (TIBC) and serum ferritin levels. The s-TfR levels in the 50 RA patients (mean +/- SD, 1,801 +/- 512 ng/ml) were significantly higher than those in the 20 control subjects (1,316 +/- 345 ng/ml). There were no differences in the values of s-TfR between men and women in either group, or between RA patients over and under 50 years old. Serum EPO levels in 47 RA patients were as low as 14.0 +/- 10.1 mlU/ml (mean +/- SD), ranging from 3.9 to 58.7 mIU/ml (normal range 2.8-17.2 mlU/ml), unrelated to low haemoglobin concentration. The s-TfR levels in RA patients showed negative correlations with red blood cell count, serum iron level and haemoglobin concentration, and positive correlations with ESR and serum EPO levels. However, there were no correlations between s-TfR level and markers of inflammation such as CRP, platelet count or RF titre. In conclusion, s-TfR level in RA patients could be a marker of erythropoiesis rather than of joint inflammation.

Antineutrophil cytoplasmic antibody in patients with primary Sjögren's syndrome.

The incidence, specificity and clinical significance of positivity for serum antineutrophil cytoplasmic antibody (ANCA) was investigated in 60 patients with primary Sjögren's syndrome (SjS). The indirect immunofluorescence (IIF) technique and an enzyme-linked immunosorbent assay (ELISA) were used to measure ANCA. Purified myeloperoxidase (MPO), lactoferrin (LF), cathepsin-G (CTG) and elastase (HLE) served as ANCA antigens for the ELISA. Ten (16.7%) of the 60 SjS patients showed positivity by IIF for perinuclear, but not cytoplasmic, ANCA. Four of the 60 sera were shown to be positive for LF, four for MPO, 0 for CTG and 0 for HLE by ELISA. There was no correlation between ANCA positivity and clinical features. ANCA in patients with SjS might be an epiphenomenon of polyclonal B-cell activation.

Anti-neutrophil cytoplasmic antibody in patients with systemic lupus erythematosus is unrelated to clinical features.

To investigate the incidence, the specificity and clinical significance of positivity for serum anti-neutrophil cytoplasmic antibody (ANCA) in 31 patients with systemic lupus erythematosus (SLE), the indirect immunofluorescence (IIF) technique and enzyme-linked immunosorbent assay (ELISA) were used to measure ANCA. Purified myeloperoxidase (MPO), lactoferrin (LF), cathepsin-G (CTG) and elastase (HLE) served as ANCA antigens for ELISA. Thirteen (42%) of the 31 SLE patients showed positivity for perinuclear, but not cytoplasmic, ANCA by IIF. Five of 31 sera were positive for MPO, 10 for LF, 1 for CTG and 0 for HLE by ELISA. Patients positive for ANCA had a higher score of SLE disease activity index (SLEDAI) than those without ANCA. There was no correlation between ANCA positivity, clinical manifestations, or organic involvement. While the ANCA in patients with SLE reflected disease activity, it was unrelated to organic involvement.

Co-existence of non-Hodgkin's lymphoma in the leukemic phase and polyarthritis simulating rheumatoid arthritis.

The patient, a 64-year-old male, complained of morning stiffness, polyarthralgia and bilateral knee joint swelling with leukocytosis (24,200/microliter) in peripheral blood. The leukocyte differentiation revealed 54% medium-size immature lymphocytes. The majority of lymphocytes showed the B-cell characteristics of IgGk monoclonality, and CD19+ and CD20+ in cell surface phenotype, suggesting a B-cell malignancy, non-Hodgkin lymphoma in the leukemic phase. Arthropathy associated with lymphoid malignancy was suspected. However, the infiltrated leukocytes in the synovial fluid of the left knee joint were dominantly neutrophils and CD3+ T-cells, and compatible with the findings in rheumatoid arthritis (RA). The association of B-cell malignancy and RA is not frequently reported. We discuss the common underlying immunological abnormalities in both B-cell malignancy and RA.

Stimulation by interleukin-7 of mononuclear cells in peripheral blood, synovial fluid and synovial tissue from patients with rheumatoid arthritis.

To determine how interleukin-7 (IL-7) affects the proliferation of T cells in patients with rheumatoid arthritis (RA), we evaluated the response of mononuclear cells (MNC) obtained from their peripheral blood (PB), synovial fluid (SF) and synovial tissue (ST) to stimulation by recombinant IL-7 and interleukin-2 (IL-2). Each cytokine was administered alone or combined with phytohemagglutinin (PHA). Cellular DNA synthesis was assayed by the [3H]-thymidine incorporation method. The stimulatory effect of 500 u/ml IL-7 on PBMNC obtained from 19 patients with RA was significantly lower than on PBMNC from 19 healthy controls. However, the same degree of stimulatory activity of 500 u/ml IL-2 was observed on the PBMNC from both RA patients and control subjects. The response of PBMNC to a suboptimal dose of PHA (0.2 micrograms/ml) was enhanced by adding either IL-7 or IL-2 (100 or 500 u/ml) to the cultures. The enhanced synthesis of DNA by both RA and control PBMNC on exposure to IL-7 following stimulation by a suboptimal dose of PHA was higher than that of IL-2. The effect of IL-7 on RA PBMNC was significantly greater than that of IL-2 at the concentration of 100 u/ml on PBMNC from the same RA patients. The stimulatory activity of IL-2 at the concentrations of 100 and 500 u/ml on SF MNC and ST MNC exceeded that of IL-7. In particular, an IL-2 dose of 500 u/ml had a marked effect on SF MNC. The PHA response of SF MNC was the lowest seen among the MNC from three different compartments.(ABSTRACT TRUNCATED AT 250 WORDS)

Frequency of gamma delta T cells in peripheral blood, synovial fluid, synovial membrane and lungs from patients with rheumatoid arthritis.

The percentages and absolute numbers of gamma delta T cells per CD3 positive cells (T cells) in four different compartments, namely peripheral blood, synovial fluid, synovial membrane and lungs from patients with rheumatoid arthritis (RA) and in peripheral blood from healthy controls were studied by two color flow-cytometric analysis. The percentages (mean +/- SEM = 6.3 +/- 0.8%, n = 22) and absolute numbers (70 +/- 11/microliters, n = 22) of gamma delta T cells in peripheral blood from RA patients were not different from those of 22 age-matched healthy controls (7.5 +/- 0.9%, 81 +/- 17/microliters, respectively). The gamma delta T cells in peripheral blood from 50 RA patients were, however, significantly decreased in negative correlation with the value of CRP as a marker for inflammation, although they had no correlation with the titer of rheumatoid factor as an autoantibody. The percentages of gamma delta T cells in synovial fluid from 10 patients (3.3 +/- 0.5%, n = 10) or in synovial membrane from 5 patients (4.2 +/- 1.9%, n = 5) and in bronchoalveolar lavage fluid from 6 patients (3.6 +/- 0.8%, n = 6) were not different from those in peripheral blood from the same patients. Thus, gamma delta T cells are not the dominant infiltrating T cell subset in the inflammatory sites of RA patients.

Role of endogenous prostaglandin E2 in interleukin 1 production by peripheral blood monocytes from patients with rheumatoid arthritis.

We studied the effect of endogenous prostaglandin E2 (PGE2) on interleukin 1 (IL-1) production by peripheral blood monocytes from patients with rheumatoid arthritis (RA). IL-1 production by RA monocytes was not different from that of monocytes from normal controls, when the cells were either unstimulated or stimulated with lipopolysaccharide (LPS, 20 micrograms/ml), as measured by two different bioassays (thymocyte or fibroblast proliferation assay) and enzyme-linked immunosorbent assay. However, IL-1 production by LPS-stimulated monocytes from RA patients cultured in medium containing indomethacin, an inhibitor of PGE2 synthesis, was significantly greater than that of monocytes from normal controls. In addition, the levels of PGE2 in culture supernatants of unstimulated or LPS-stimulated monocytes from RA patients were higher than in culture supernatants of monocytes from normal controls. Moreover, the increase of in vitro IL-2 production by RA T cells stimulated by phytohemagglutinin (PHA) was observed when monocytes were removed from peripheral blood mononuclear cells. These results indicated that peripheral blood monocytes from RA patients could produce IL-1 in excess in vitro, but that in vivo IL-1 production by RA monocytes and IL-2 induction by RA T cells might be negatively regulated by endogenous PGE2.

Increased ability of peripheral blood B cells from patients with rheumatoid arthritis to produce interleukin 1 in vitro.

Twenty-four patients with rheumatoid arthritis (RA) and 20 normal controls were examined for the ability of their peripheral blood B cells to produce interleukin 1 (IL-1) with or without lipopolysaccharide (LPS). B cells were purified from peripheral blood by negative selection methods (i.e., removal of adherent cells and sheep red blood cell rosette-forming cells, followed by treatment with monoclonal antibodies (OKT3 and OKM1) and complement). The amount of IL-1 in B cell culture supernatants (SN) was measured by thymocyte and fibroblast proliferation assays and an enzyme-linked immunosorbent assay for IL-1 alpha and beta. As a group, cultured B cells from patients with RA, both spontaneously and when stimulated with LPS, produced higher levels of IL-1 than those from normal controls. IL-1 production by RA B cells with LPS had a weak but positive correlation with disease activity. Moreover, RA B cell culture SN with elevated levels of IL-1 had a synergistic effect on the growth of anti-human IgM (anti-mu) stimulated B cells. In separate experiments, the growth of RA B cells was significantly promoted by IL-1 beta both with and without anti-mu stimulation. These results suggest that B cell-derived IL-1 may be involved in the B cell clonal expansion of RA through its own activity as a B cell stimulatory factor.