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1.
Scand J Rheumatol ; 36(2): 107-10, 2007.
Article in English | MEDLINE | ID: mdl-17476616

ABSTRACT

BACKGROUND: The disproportionate ferritin response encountered in some patients with adult Still's disease (ASD) may reflect a fundamental aspect in the pathophysiology of ASD. METHODS: An observational case-control study of 22 ASD patients followed for 63 months. Baseline laboratory data were compared with age- and gender-matched controls with new-onset rheumatoid arthritis (RA). Serum levels of ferritin and C-reactive protein (CRP) and the ferritin/CRP ratio were related to clinical outcome in ASD through nonparametric statistical analyses. RESULTS: Compared to RA patients, haemoglobin levels were lower (11.8 vs. 13.5 g/dL; p = 0.009) and leucocyte counts (17.1 vs. 8.6 10(9)/mL; p<0.001), erythrocyte sedimentation rate (ESR) (84 vs. 38 mm; p = 0.001), CRP (154 vs. 27 mg/L; p<0.001), aspartate aminotransferase (ASAT) (52 vs. 23 U/l; p = 0.004), serum ferritin (8750 vs. 62 microg/L; p<0.001) and ferritin/CRP ratios (9.7 vs. 1.7; p<0.001) were higher in ASD patients at baseline. Six patients (27%) achieved sustained remission (monocyclic disease), while 16 patients (73%) developed chronic disease (progressive in 27%, relapsing/remitting in 46%). The levels of ESR and CRP or other baseline variables were not associated with outcome. However, baseline serum ferritin was significantly higher in ASD patients with chronic disease (p = 0.04), while a cut-off of five times the normal upper level (NUL) was 100% sensitive and 60% specific for predicting chronic disease. CONCLUSION: An exaggerated ferritin response with levels>5 times the NUL and high ferritin/CRP ratios is useful for distinguishing between ASD and RA patients. Ferritin levels>5 times the NUL are also associated with a chronic disease course.


Subject(s)
C-Reactive Protein/analysis , Ferritins/blood , Still's Disease, Adult-Onset/blood , Adult , Biomarkers , Case-Control Studies , Female , Ferritins/immunology , Follow-Up Studies , Humans , Inflammation/immunology , Male , Middle Aged , Still's Disease, Adult-Onset/diagnosis
2.
Br J Cancer ; 75(10): 1447-53, 1997.
Article in English | MEDLINE | ID: mdl-9166936

ABSTRACT

Isolated limb perfusion with tumour necrosis factor alpha (TNF-alpha) and melphalan is well tolerated and highly effective in irresectable sarcoma and melanoma. No data are available on isolated hepatic perfusion (IHP) with these drugs for irresectable hepatic malignancies. This study was undertaken to assess the feasibility of such an approach by analysing hepatic and systemic toxicity of IHP with TNF-alpha with and without melphalan in pigs. Ten healthy pigs underwent IHP. After vascular isolation of the liver, inflow catheters were placed in the hepatic artery and portal vein, and an outflow catheter was placed in the inferior vena cava (IVC). An extracorporeal veno-venous bypass was used to shunt blood from the lower body and intestines to the heart. The liver was perfused for 60 min with (1) 50 microg kg(-1) TNF-alpha (n = 5), (2) 50 microg kg(-1) TNF-alpha plus 1 mg kg(-1) melphalan (n = 3) or (3) no drugs (n = 2). The liver was washed with macrodex before restoring vascular continuity. All but one pigs tolerated the procedure well. Stable perfusion was achieved in all animals with median perfusate TNF-alpha levels of 5.1 +/- 0.78 x 10(6) pg ml(-1) (+/- s.e.m). Systemic leakage of TNF-alpha from the perfusate was consistently < 0.02%. Following IHP, a transient elevation of systemic TNF-alpha levels was observed in groups 1 and 2 with a median peak level of 23 +/- 3 x 10(3) pg ml(-1) at 10 min after washout, which normalized within 6 h. No significant systemic toxicity was observed. Mild transient hepatotoxicity was seen to a similar extent in all animals, including controls. IHP with TNF-alpha with(out) melphalan in pigs is technically feasible, results in minimal systemic drug exposure and causes minor transient disturbances of liver biochemistry and histology.


Subject(s)
Antineoplastic Agents, Alkylating/toxicity , Chemical and Drug Induced Liver Injury , Melphalan/toxicity , Tumor Necrosis Factor-alpha/toxicity , Alanine Transaminase/metabolism , Animals , Antineoplastic Agents, Alkylating/administration & dosage , Aspartate Aminotransferases/metabolism , L-Lactate Dehydrogenase/metabolism , Liver/blood supply , Liver/drug effects , Liver/metabolism , Liver Diseases/metabolism , Liver Diseases/pathology , Melphalan/administration & dosage , Perfusion , Swine , Tumor Necrosis Factor-alpha/administration & dosage , Tumor Necrosis Factor-alpha/metabolism
4.
J Am Coll Cardiol ; 23(7): 1677-81, 1994 Jun.
Article in English | MEDLINE | ID: mdl-8195531

ABSTRACT

OBJECTIVES: We studied 30 consecutive children with isolated heart block to assess the clinical impact of the presence of maternal anti-Ro/SS-A antibodies for isolated heart block. BACKGROUND: Isolated heart block in children, often associated with maternal autoimmune disease leading to anti-Ro/SS-A auto-antibody production, is an infrequent but potentially lethal disorder. METHODS: Thirty children with isolated heart block were studied with respect to medical history and electrocardiographic (ECG) analysis. The presence of anti-Ro/SS-A antibodies was determined in the maternal serum. We also examined the ECGs of all brothers and sisters of the patients for conduction abnormalities. RESULTS: Twenty-one of the 30 children had an anti-Ro/SS-A-positive mother (group A); the other 9 children had an anti-Ro/SS-A-negative mother (group B). Comparison of the clinical data from both mothers and children revealed that these two groups differed significantly with respect to the following: Prenatal diagnosis and obstetric complications occurred more often in group A, whereas progression to complete block, QRS width > 0.08 s, premature ventricular contractions and ventricular standstills > 4.5 s occurred more often in group B. In addition, mothers of children in group A reported more spontaneous abortions. All siblings of children in groups A and B had normal ECGs, excluding a subclinical form of heart block. CONCLUSIONS: Two types of heart block can be recognized: Congenital heart block is associated with maternal anti-Ro/SS-A antibodies and numerous obstetric and neonatal complications. It is diagnosed prenatally or at birth and is usually complete at onset and probably has a substantial recurrence risk. Heart block that is acquired later in life is not associated with maternal autoimmunity and has no risk for recurrence. It often presents as a partial block but progresses to complete block in time.


Subject(s)
Autoantibodies/analysis , Heart Block/immunology , Sjogren's Syndrome/immunology , Adolescent , Autoimmune Diseases/immunology , Child , Child, Preschool , Female , Heart Block/genetics , Heart Block/physiopathology , Humans , Infant , Male
5.
Ann Rheum Dis ; 52(2): 127-32, 1993 Feb.
Article in English | MEDLINE | ID: mdl-8447692

ABSTRACT

The specificity of T cells in the inflamed joints of patients with rheumatoid arthritis (RA) has been the subject of much study. Bacterial antigens are suspect in the aetiology of rheumatic diseases. The responsiveness of the mononuclear cell fraction of peripheral blood and synovial fluid of patients with RA and of patients with rheumatic diseases other than RA to bacterial antigens such as cell wall fragments of the anaerobic intestinal flora, cell wall fragments of Streptococcus pyogenes, intestinal flora derived peptidoglycan polysaccharide complexes, the 65 kilodalton protein of Mycobacterium tuberculosis, and muramyldipeptide was investigated. No significant difference in response was found to all these bacterial antigens in the synovial fluid of patients with RA compared with the responses in patients with other rheumatic diseases. The highest responsiveness in the synovial fluid of the patients with RA was to the streptococcal cell wall fragments and to the 65 kilodalton protein. Higher responses to several bacterial antigens in the synovial fluid of patients with RA were found compared with peripheral blood from the same patient group. The antigen presenting cell population of the synovial fluid in patients with RA and the patients with other rheumatic diseases was found to be stimulatory for autologous peripheral blood T cells even in the absence of antigen. This suggests an important role for the synovial antigen presenting cell in the aetiology of inflammatory joint diseases.


Subject(s)
Antigen-Presenting Cells/immunology , Antigens, Bacterial/immunology , Arthritis/immunology , Leukocytes, Mononuclear/immunology , Synovial Fluid/immunology , Adult , Aged , Aged, 80 and over , Arthritis, Rheumatoid/immunology , Cell Division , Humans , Middle Aged , T-Lymphocytes/immunology
6.
Arthritis Rheum ; 36(2): 168-80, 1993 Feb.
Article in English | MEDLINE | ID: mdl-8431205

ABSTRACT

OBJECTIVE: In vitro, activated neutrophils create a microenvironment in which proteinase inhibitors are inactivated through the coordinate action of reactive oxygen species and released elastase. We investigated whether such a mechanism may contribute to the destruction of the joint tissues in arthritis. METHODS: We analyzed the state of alpha 1-antitrypsin (alpha 1AT) and alpha 1-antichymotrypsin (alpha 1ACT), the two major inhibitors of the neutrophilic serine proteinases, in synovial fluid (SF) from patients with inflammatory arthropathies (n = 71) and osteoarthritis (OA) (n = 11), and related the results to neutrophil activation in SF. RESULTS: The ratio of functional to antigenic levels of alpha 1AT in SF of patients with inflammatory joint diseases was similar to that of alpha 1AT in normal plasma, whereas that of alpha 1ACT was significantly decreased. Patients with inflammatory arthropathies had significantly higher levels of inactivated alpha 1AT (i alpha 1AT) and inactivated alpha 1ACT (i alpha 1ACT) in SF (as determined with monoclonal antibodies specific for the inactivated [i.e., proteolytically inactivated and/or complexed] forms of these inhibitors) than patients with OA (P < 0.005). Inactivated alpha 1AT and i alpha 1ACT levels corresponded to 0.3-11% and 3-99%, respectively, of the total amount of these inhibitors in SF. Most of the i alpha 1AT in SF had a lower M(r) than that of native alpha 1AT. Inactivated alpha 1ACT in SF had an M(r) identical to that of nonfunctional alpha 1ACT in plasma treated with chymotrypsin. Levels of both i alpha 1AT and i alpha 1ACT correlated significantly with lactoferrin and elastase levels. CONCLUSION: These results suggest that alpha 1AT and alpha 1ACT in arthritic joints are inactivated in part by activated neutrophils, suggesting a role for these cells in impairment of the local balance between proteinases and their inhibitors in arthritis.


Subject(s)
Arthritis, Rheumatoid/metabolism , Neutrophils/metabolism , alpha 1-Antichymotrypsin/metabolism , alpha 1-Antitrypsin/metabolism , Electrophoresis, Polyacrylamide Gel/methods , Enzyme Activation , Humans , Sodium Dodecyl Sulfate , Synovial Fluid/cytology
7.
Arthritis Rheum ; 35(8): 884-93, 1992 Aug.
Article in English | MEDLINE | ID: mdl-1379429

ABSTRACT

OBJECTIVE: Intraarticular activation of the fibrinolytic system has been suspected to occur in patients with arthritis. We undertook the present study to investigate the relation of this activation to clinical symptoms, and the molecular pathways involved. METHODS: We quantitatively assessed levels of plasmin-alpha 2-antiplasmin (PAP) complexes in synovial fluid (SF) from 25 patients with rheumatoid arthritis (RA), 7 with seronegative spondylarthropathy (SSA), and 10 with osteoarthritis (OA), and conducted an analysis to determine the plasminogen-activating pathway via which these complexes were generated. In addition, we studied the relationship of intraarticular fibrinolysis to clinical and biochemical parameters. RESULTS: All patients studied had increased SF levels of PAP complexes. Levels in patients with RA and SSA were slightly higher than those in patients with OA. These complexes were probably formed by activation of urokinase-type plasminogen activator (u-PA), and not tissue-type plasminogen activator (t-PA), since SF levels of both u-PA antigen and u-PA-plasminogen activator inhibitor (PAI) complexes were increased in 27 of the 42 patients. Conversely, SF levels of t-PA were below normal in all but 1 patient. In some patients, activation of factor XII presumably also contributed to plasminogen activation in SF, since levels of factor XIIa-C1 inhibitor in SF were increased in 8 of the 42 patients and correlated, as did u-PA-PAI levels, with levels of PAP complexes. Several of the parameters of fibrinolysis in SF, particularly u-PA antigen and u-PA-PAI-1 complexes, were found to correlate with clinical and biochemical parameters. CONCLUSION: Our results suggest that plasminogen is frequently activated in the joints of patients with inflammatory or noninflammatory arthropathy and that this activation mainly occurs via a u-PA-, and in some cases also via a factor XII-, dependent pathway. The possible relation of this activation process to stimulation of synovial cells by cytokines is discussed.


Subject(s)
Arthritis, Rheumatoid/physiopathology , Cartilage, Articular/physiopathology , Fibrinolysis/physiology , Joint Diseases/physiopathology , Osteoarthritis/physiopathology , Spondylitis, Ankylosing/physiopathology , Adult , Aged , Aged, 80 and over , Arthritis, Rheumatoid/blood , Electrophoresis, Polyacrylamide Gel , Factor XII/physiology , Female , Fibrinolysin/analysis , Humans , Male , Middle Aged , Osteoarthritis/blood , Plasminogen Inactivators/analysis , Plasminogen Inactivators/metabolism , Spondylitis, Ankylosing/blood , Synovial Fluid/chemistry , Thymine Nucleotides/analysis , Urokinase-Type Plasminogen Activator/analysis , Urokinase-Type Plasminogen Activator/metabolism , Urokinase-Type Plasminogen Activator/physiology , alpha-Macroglobulins/analysis
8.
Clin Rheumatol ; 10(1): 23-7, 1991 Mar.
Article in English | MEDLINE | ID: mdl-2065503

ABSTRACT

Kidney involvement in Sjögren's syndrome (SS) including renal tubular disorders are well recognized but little is known about frequency and extent of such dysfunction in the general population of patients with primary SS, due to a lack of group studies. We studied 27 patients with primary SS and without other possible causes of tubular dysfunction. Increased urinary beta 2M excretion, due to proximal tubular dysfunction, was present in 26% of patients. Inadequate urine acidification after oral NH4 Cl, proving distal tubular dysfunction, was found in 12% of the patients studied. Concentrating ability, tested by thirst, was decreased in 44% of patients studied. Abnormal renal tubular tests correlated with presence of ANA (p = 0.05) but not with other clinical parameters. In conclusion demonstrable renal tubular dysfunctions occur in over half the patients with primary SS. Literature concerning this subject is discussed.


Subject(s)
Kidney Tubules/physiopathology , Sjogren's Syndrome/physiopathology , Administration, Oral , Adult , Aged , Ammonium Chloride/administration & dosage , Ammonium Chloride/pharmacology , Female , Humans , Kidney Concentrating Ability/drug effects , Kidney Concentrating Ability/physiology , Kidney Function Tests , Kidney Tubules/pathology , Male , Middle Aged , Sjogren's Syndrome/pathology , Sjogren's Syndrome/urine , beta 2-Microglobulin/urine
9.
Ann Intern Med ; 114(3): 183-8, 1991 Feb 01.
Article in English | MEDLINE | ID: mdl-1984742

ABSTRACT

OBJECTIVE: To determine the outcome of renal transplantation in patients with systemic lupus erythematosus and end-stage renal failure and to compare disease activity after transplantation with disease activity before transplantation. DESIGN: Retrospective case finding using data for an 8-year period from the central registry for renal replacement therapy in The Netherlands. SETTING: Tertiary care hospitals with facilities for renal transplantation in the Netherlands. PATIENTS: Twenty-eight patients who fulfilled at least four of the American Rheumatology Association's criteria for the classification of systemic lupus erythematosus and who received a renal transplant. MEASUREMENTS: Actuarial survival rates for grafts and patients after transplantation, maximal nonrenal scores on the Systemic Lupus Erythematosus Disease Activity Index, and time-adjusted disease exacerbation rates in all patients before and after transplantation. RESULTS: The actuarial graft survival rate at 1 year and 5 years was 68% (95% CI, 47% to 82%) and 54% (CI, 25% to 77%), respectively, whereas the actuarial patient survival rate was 87% (CI, 69% to 96%) at 1 and 5 years. High disease activity was not found to affect graft survival adversely before the start of renal replacement therapy or during dialysis. After transplantation, disease activity per patient and the overall incidence of disease exacerbations decreased. One case of recurrent lupus nephritis was seen. CONCLUSIONS: Patients with systemic lupus erythematosus and end-stage renal failure are excellent candidates for renal transplantation; disease activity after transplantation is sporadic and low, and the recurrence of lupus nephritis is rare.


Subject(s)
Graft Survival/physiology , Kidney Failure, Chronic/surgery , Kidney Transplantation/physiology , Lupus Erythematosus, Systemic/physiopathology , Lupus Nephritis/surgery , Actuarial Analysis , Adolescent , Adult , Female , Follow-Up Studies , Humans , Kidney Failure, Chronic/etiology , Lupus Nephritis/physiopathology , Male , Middle Aged , Severity of Illness Index , Survival Rate
10.
Am J Med ; 89(2): 169-74, 1990 Aug.
Article in English | MEDLINE | ID: mdl-2382665

ABSTRACT

PURPOSE: To compare disease activity in patients with systemic lupus erythematosus (SLE) (1) before and after the onset of end-stage renal failure and (2) during hemodialysis and continuous ambulatory peritoneal dialysis (CAPD). PATIENTS AND METHODS: Records of 55 patients with SLE currently being treated with dialysis were reviewed. Disease activity was measured according to the SLE Disease Activity Index, event rates per 1,000 months' patient observation, and use of medication. RESULTS: In the majority of patients, deterioration of renal function was slowly progressive over more than 2 years. After the initiation of dialysis for end-stage renal failure, maximal extrarenal disease activity and use of medication decreased markedly, but event rates for specific nonrenal manifestations of lupus did not decrease. Overall survival with dialysis was 89% after 5 years. During dialysis no difference was found in disease activity and use of medication between treatment with either hemodialysis of CAPD. Thrombocytopenia and elevated levels of anti-double-stranded DNA, however, occurred more frequently during CAPD. CONCLUSION: Patients with SLE have excellent survival rates with dialysis; their disease activity is diminished during dialysis but not abolished. No difference in survival or disease activity was found between patients undergoing hemodialysis or CAPD.


Subject(s)
Kidney Failure, Chronic/therapy , Lupus Erythematosus, Systemic/complications , Peritoneal Dialysis, Continuous Ambulatory , Renal Dialysis , Adult , Female , Humans , Incidence , Kidney Failure, Chronic/etiology , Kidney Failure, Chronic/mortality , Lupus Erythematosus, Systemic/mortality , Lupus Erythematosus, Systemic/therapy , Male , Peritoneal Dialysis, Continuous Ambulatory/adverse effects , Survival Rate , Thrombocytopenia/epidemiology
11.
Arthritis Rheum ; 33(7): 970-7, 1990 Jul.
Article in English | MEDLINE | ID: mdl-2369432

ABSTRACT

We reassessed renal biopsy specimens from 116 patients with systemic lupus erythematosus and clinical manifestations of lupus nephritis to determine the contributions of the World Health Organization classification system, the activity and chronicity indexes of the National Institutes of Health scoring system, and various clinical parameters at the time of biopsy to predicting disease outcome. Multivariate analysis showed that only a chronicity index greater than 3 was predictive for decreased renal survival, while age greater than 31 years at biopsy and a chronicity index greater than 3 were associated with decreased patient survival. Clinical tests of renal function were not reliable in discriminating between active lesions and chronic renal damage.


Subject(s)
Kidney/pathology , Lupus Nephritis/pathology , Adult , Biopsy , Female , Humans , Lupus Nephritis/diagnosis , Lupus Nephritis/mortality , Male , Peritoneal Dialysis , Prognosis , Renal Dialysis/mortality
13.
J Rheumatol ; 17(6): 771-6, 1990 Jun.
Article in English | MEDLINE | ID: mdl-2388198

ABSTRACT

The influence of systemic lupus erythematosus (SLE) on pregnancy and vice versa was examined during 39 pregnancies in 19 patients, and outcome was compared with 24 pregnancies in 18 other patients before SLE was established. No difference in fetal loss or premature birth rate was found, although more babies were born with low birth weight after SLE was diagnosed; there was a preponderance of female babies in both groups. Pregnancy during SLE was accompanied by disease exacerbations in up to 74% of all patients. These exacerbations concerned mostly musculoskeletal (41%) and hematological abnormalities (36%), while organ involvement occurred in 13% of all exacerbations. No differences in pregnancy outcome during SLE were found between patients with active or quiescent disease, as established by the lupus activity criteria count (LACC). The presence of antibodies to SSA in the mother was associated with the occurrence of congenital heart block; no association was found between antiphospholipid antibodies and fetal loss.


Subject(s)
Lupus Erythematosus, Systemic/complications , Pregnancy Complications , Pregnancy Outcome , Adult , Antibodies, Antinuclear/analysis , Complement System Proteins/analysis , Female , Humans , Infant Mortality , Infant, Newborn , Lupus Erythematosus, Systemic/epidemiology , Lupus Erythematosus, Systemic/immunology , Pregnancy , Pregnancy Complications/immunology , Prospective Studies
14.
J Immunol Methods ; 109(1): 27-35, 1988 Apr 22.
Article in English | MEDLINE | ID: mdl-3282012

ABSTRACT

Antibodies to dsDNA differ in their avidity towards the antigen. The electrostatic interaction between DNA and anti-DNA is sensitive to increases in pH and/or ionic strength and therefore, elution studies employing either of these permit discrimination between anti-dsDNA populations that differ in avidity. Another way to determine anti-dsDNA avidity is the calculation of Farr/PEG ratios. These are obtained by division of the amount of anti-DNA measured with the Farr assay (which does not detect low avidity anti-dsDNA) by the amount measured with the PEG assay (which does detect low avidity anti-dsDNA). With these separate approaches, we compared the sera of 17 SLE patients with nephritis with the sera of 17 patients with central nervous system (CNS) involvement. Farr/PEG ratios and sensitivity to high pH elution of anti-dsDNA in the sera of these patients both permitted discrimination between the two groups of patients. The anti-dsDNA of patients with nephritis was found to have a significantly higher avidity towards DNA than anti-dsDNA of patients with cerebral disease. We also observed a significant correlation between Farr/PEG ratios and the salt lability of anti-dsDNA.


Subject(s)
Antibodies, Antinuclear/analysis , Antibody Affinity , Antigen-Antibody Complex/metabolism , DNA/immunology , Immunologic Techniques , Antibodies, Antinuclear/isolation & purification , Fluorescent Antibody Technique , Humans , Lupus Erythematosus, Systemic/immunology , Polyethylene Glycols
15.
Arthritis Rheum ; 30(6): 607-17, 1987 Jun.
Article in English | MEDLINE | ID: mdl-3606679

ABSTRACT

Putative cross-reactions between anti-DNA and anticardiolipin activities were studied using sera of different patients and a panel of monoclonal antibodies to DNA. Sera were obtained from patients with systemic lupus erythematosus, from patients with syphilis, and from heroin addicts who showed a biologic false-positive result on the serologic test for syphilis. While the patients with syphilis and the heroin addicts had elevated levels of anticardiolipin antibodies in their circulation, no reactivity with DNA was observed in these sera. Sera from systemic lupus erythematosus patients often showed both anti-DNA and anticardiolipin activity. Although a correlation between anti-DNA and anticardiolipin titers was found, this did not always result from cross-reactivity of the same population of antibodies. In fact, we observed a relationship between cross-reactivity and antibody avidity. Anti-DNA of high avidity to DNA showed little cross-reactivity with cardiolipin. Anticardiolipin activity in such sera was based on the presence of specific anticardiolipin antibodies. Anti-DNA of low avidity was found to cross-react with cardiolipin. Among monoclonal antibodies to DNA, we found that cross-reactions with cardiolipin were rare: only 6 of 55 anti-DNA clones produced antibodies that also reacted with cardiolipin.


Subject(s)
Autoantibodies/immunology , Cardiolipins/immunology , DNA/immunology , Antibody Affinity , Cross Reactions , Heroin Dependence/immunology , Humans , Lupus Erythematosus, Systemic/immunology , Syphilis Serodiagnosis
16.
J Immunol ; 135(1): 265-71, 1985 Jul.
Article in English | MEDLINE | ID: mdl-3923103

ABSTRACT

In sera of patients suffering from an exacerbation of systemic lupus erythematosus (SLE), increased amounts of abnormal C1q were detected, contrasting with decreased or even undetectable levels of normal C1q in these sera. When analyzed immunochemically by double immunodiffusion, this low m.w. C1q (LMW-C1q) appeared to be identical with the defective C1q in serum of individuals with an inherited, homozygous inability to produce functional plasma C1q. These persons show a tendency to develop SLE-like syndromes. Like the genetically defective C1q, the abnormal C1q molecule in SLE sera was hemolytically inactive, did not incorporate in C1, was found in the supernatant of euglobulin-precipitated serum, and appeared in the break-through fraction of a cation-exchange column. Sucrose gradients and gel filtration analyses supported the putative identity of the molecules. SDS-PAGE and immunoblots revealed the presence of subunits that reacted with antibodies against C1q and confirmed the C1q-like nature of LMW-C1q. Low levels of LMW-C1q were also detected in serum and plasma of normal individuals. A radial immunodiffusion technique was used to measure LMW-C1q in the serum of 54 patients. Although these patients were not selected for parameters of disease activity, their levels of LMW-C1q were significantly higher than those of normal individuals and children with decreased C3 levels due to acute glomerulonephritis.


Subject(s)
Complement Activating Enzymes/analysis , Lupus Erythematosus, Systemic/immunology , Centrifugation, Density Gradient , Chromatography, Ion Exchange , Complement Activating Enzymes/deficiency , Complement Activating Enzymes/genetics , Complement C1q , Electrophoresis, Polyacrylamide Gel , Humans , Immunodiffusion , Lupus Erythematosus, Systemic/genetics , Molecular Weight
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