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Prepublished online as a Blood First Edition Paper on April 17, 2002; DOI 10.1182/blood-2002-01-0128. This Article Abstract Full Text (PDF) All Versions of this Article: 2002-01-0128v1 100/1/353    most recent Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Rights and Permissions Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Goldammer, A. Articles by Haas, M. Search for Related Content PubMed PubMed Citation Articles by Goldammer, A. Articles by Haas, M. Related Collections Immunobiology Brief Reports Related Letter in Blood Online Social Bookmarking                   What's this?  Previous Article  |  Table of Contents  |  Next Article  Blood, 1 July 2002, Vol. 100, No. 1, pp. 353-355 BRIEF REPORT Influence of plasma immunoglobulin level on antibody synthesis Andreas Goldammer, Kurt Derfler, Kurt Herkner, Arthur R. Bradwell, Walter H. Hörl, and Martin Haas From the Department of Internal Medicine III, Division of Nephrology and Dialysis, and Department of Pediatric Laboratory Medicine, University Hospital Vienna, Austria; and the Department of Immunology, The Medical School, University of Birmingham, England.     Abstract Top Abstract Introduction Study design Results and discussion References In previous experimental animal studies it has been demonstrated that antibody depletion is not followed by increased antibody synthesis. To assess whether these results are conferrable to antibody-depleted humans, we measured free light chains (flcs) as markers of current antibody synthesis in 8 patients treated with immunoadsorption (IA) therapy. Specific and bulk immunoglobulin levels were obtained simultaneously. The mean serum flc concentration increased to the preapheresis value within 1 day and remained unchanged thereafter. Total immunoglobulin G (IgG) and specific antibody concentrations increased to pretreatment values in 88% and 43% of the patients, respectively, and remained below the original values in the others. In conclusion, the lack of increased flc synthesis after IA confirms the absence of a feedback mechanism regulating antibody synthesis. The restoration of serum IgG levels after IA, therefore, does not result from increased antibody synthesis but is probably related to changes of catabolism and immunoglobulin backflow. (Blood. 2002;100:353-355) © 2002 by The American Society of Hematology.     Introduction Top Abstract Introduction Study design Results and discussion References The regulation of serum antibody levels has been a subject of debate for several decades. A large number of studies have provided evidence for enhanced antibody synthesis after immunoglobulin depletion and thus for the existence of an immunoregulatory feedback mechanism.1-7 In contrast, Charlton and colleagues8-10 demonstrated with a series of animal experiments that the rapid increase of antibody serum levels after plasmapheresis could be explained by immunoglobulin backflow from extravascular space and decreased catabolism alone. More than 10 years later the lack of an increased antibody synthesis in a low immunoglobulin state was confirmed in the excellent studies by Junghans and Anderson11 and by Junghans.12 Knock-out mice with disrupted immunoglobulin G (IgG) protection receptors, which effect increased catabolism of IgG and subsequently low IgG serum levels, had a similar biosynthesis rate as normal control subjects. The complex metabolism of IgG has so far prevented exact measurement of immunoglobulin synthesis in humans with low antibody levels. However, a prerequisite for immunoglobulin assembly is the synthesis of free light chains (flcs) that are produced in excess during antibody production and secreted as free  or  monomers into the vascular space.13,14 Because flcs have a half-live of only 2 to 4 hours,15 they reflect current immunoglobulin production and can be used for estimating the activity of diseases accompanied by autoantibody synthesis.16,17 We hypothesized that increased antibody synthesis after immunoglobulin depletion would be accompanied by increased flc serum levels and measured free  and  light chain concentrations in 8 patients undergoing immunoadsorption (IA) therapy.     Study design Top Abstract Introduction Study design Results and discussion References The study protocol was approved by the local ethics committee, and the patients' informed consent was obtained. Eight patients with various autoimmune diseases and normal kidney function treated with IA therapy were recruited (Table 1). Concomitant immunosuppressive therapy was prednisolone (n = 4), mycophenolate mofetil (n = 3), and cyclosporine A (n = 1); 3 patients received no additional therapy. We recruited additionally 3 patients with familial hypercholesterolemia, who were treated with regular low-density lipoprotein (LDL)-cholesterol apheresis, as control subjects. The IA and LDL apheresis therapy procedure used at our institution was described previously.18,19 In brief, peripheral venous blood was drawn and the plasma separated by centrifugation. Thereafter the plasma was treated with either Ig-Therasorb columns (Therasorb, Munich, Germany), coated with sheep antihuman immunoglobulin antibodies, or LDL-Therasorb columns (Therasorb), coated with anti-LDL antibodies. Blood samples were analyzed immediately before and after plasmapheresis and at days 1, 3, and 5 after treatment. Measurement of flc was performed by a latex-enhanced immunoassay20 with a lower detection range for free  and  light chains of 3.4 mg/L. The blood levels of serum immunoglobulins (IgG, IgA, IgM) and of specific autoantibodies (thyroglobulin, acetylcholine receptor, double-stranded DNA (dsDNA), and antinuclear antibody/antinuclear factor) were determined with the use of standard methods. To exclude only B-cell activation by IA therapy or activation of the underlying disease, which would have increased immunoglobulin synthesis and interfered with the flc synthesis rate, in vivo B-cell activity was measured by 4-color flow cytometry before and during the post-IA period by using 3 different antibodies (CD38, CD43, and CD22; all antibodies by Immunotech, Marseille, France). Activation of B cells was defined as an increase of CD38 and CD43 expression and reduction of CD22 expression.                                View this table: [in this window] [in a new window]   Table 1. Patient characteristics at study entrance The results are expressed as median and range. Statistical analysis was carried out by the Student t test for paired or unpaired data or Wilcoxon signed rank test. A P value < .05 was considered statistically significant.     Results and discussion Top Abstract Introduction Study design Results and discussion References Free  light chain levels decreased in 7 of 8 patients during IA and remained unchanged in one patient (Table 2). The levels increased to pretreatment values in most patients within 1 day (median difference to pretreatment values, 2% [range, 41% to 62%] with one patient below detectable limit) and remained stable thereafter (Table 2). Only one patient had a  light chain pretreatment level above normal range (patient 8), which decreased by IA but remained slightly above normal range during the observation period (normal, 8.4 ng/mL; range, 3.6-15.9 ng/mL). Flc of the  type decreased similarly during IA in all patients (Table 2). Almost all patients reached pretreatment values within 24 hours (median difference, 1%; range, 14% to 15%). The levels remained within normal range during the further course (normal, 14.5 ng/mL [range, 8.1-33 ng/mL]). The median / ratio in patients with measurable free  light chain levels was 0.49 (range, 0.33-1.30) before treatment and remained within normal range during the posttreatment period (mean, 0.54 [range, 45-0.63]; normal, 0.6 [range, 0.36-1.0]). Free  and  light chain levels before and after therapy in the 3 control patients with LDL apheresis remained unchanged throughout the study (mean , 15 ng/mL [range, 13-17 ng/mL] and mean , 18 ng/mL [range, 18-19 ng/mL]). IgG serum levels decreased by approximately 90% during IA and increased to approximately 70% of pretreatment levels within 5 days (Table 3). There was a tendency toward a slower increase of serum levels in patients receiving no adjunctive immunosuppressants (n = 4) than in patients with additional mycophenolate mofetil, cyclosporine A, or prednisolone (> 10 mg/day) therapy (median, 69%; range, 63%-85% versus 81%; range, 63%-94%; P = NS). IgM and IgA decreased by 61% (range, 47%-81%) and 68% (range, 47%-81%), respectively, and increased within 5 days to 75% (range, 52%-111%) and 81% (range, 79%-98%), respectively, of pretreatment levels. Immunoglobulin levels remained unchanged in the control patients treated with LDL apheresis. Specific antibody levels decreased substantially during IA in all patients with identifiable autoimmune disease and increased to pretreatment values in 4 of 7 patients within 5 days (Table 3).                                View this table: [in this window] [in a new window]   Table 2. Individual free light chain serum levels before and immediately after immunoadsorption and at days 1, 3, and 5 after treatment                                View this table: [in this window] [in a new window]   Table 3. Total immunoglobulin G and specific antibody levels before and immediately after immunoadsorption and at days 1, 3, and 5 after treatment The 3 different activity markers (CD22, CD38, and CD43) identified on CD19+ lymphocytes showed a normal distribution in 6 of 8 investigated patients and were not influenced by IA (data not shown). Two patients had activated B cells prior to initiation of therapy. Patient 6 had markedly increased CD38+ B cells (98%), which decreased after IA (78%). In patient 8, CD38+ (78%) and CD43+ (74%) were increased and CD22+ (42%) decreased and normalized after IA therapy (CD38+, 19%; CD43+, 21%; and CD22+, 94%). The 3 patients treated with LDL apheresis had a normal distribution of CD38+, CD43+, and CD22+ B cells throughout the study. Thus, we were able to demonstrate that immunoglobulin depletion with IA does not influence antibody synthesis which agrees with previous animal experiments describing the lack of an immunoglobulin feedback mechanism.8-11 The close correlation between flc concentration and immunoglobulin synthesis has been demonstrated in several conditions associated with B-cell activation, such as multiple sclerosis16 and systemic lupus erythematodes.17 Because B-cell activation and antibody synthesis precedes tissue injury by several weeks, flcs might even be used as reliable predictors for subsequent clinical relapse of disease.21 Thus, by demonstrating that flc serum levels remained unchanged after immunoglobulin depletion, we were able to prove that a reduction of antibody serum levels is not followed by an increased biosynthesis. Moreover, because immunoadsorption therapy not only reduced IgG but also IgM and IgA serum levels by 60% to 70% because of the use of a nonspecific adsorption column, an intrinsic feedback mechanism of other immunoglobulin classes might be excluded as well. The lack of an accelerated antibody synthesis after immunoglobulin depletion makes the widely accepted strategy of administering cytotoxic drugs during plasmapheresis, to prevent an accelerated antibody production,22 obsolete. The insufficiency of prophylactic immunosuppressive therapy on antibody rebound was demonstrated in our patients by the similar immunoglobulin increase in those treated with additional immunosuppressants, when compared with patients without concomitant cytostatic drugs. Antibody levels as well as flc levels did not differ between the groups and increased to pretreatment values equally fast. Similar to others9,12 we cannot, therefore, recommend the administration of immunosuppressants for the prevention of an increased antibody synthesis after plasmapheresis. However, patients with a chronic autoimmune disease, treated with plasmapheresis either as a result of acute exacerbation or as a long-term therapeutic strategy, will, nevertheless, profit in most cases from the long-term effects of immunosuppressants. The absence of an increase of B-cell activity after IA contradicts a previous study7 but, nevertheless, excludes the possibility that IA therapy itself might promote antibody synthesis by release of antigenic peptides. On the contrary, as indicated in the patient with active Guillain-Barré syndrome, characterized serologically by highly activated B cells and increased  light chains, removal of autoantibodies and immune complexes might lead to a normalization of both B-cell activity markers and flc levels. It is, therefore, tempting to speculate that antibody removal might not only be without influence on immunoglobulin synthesis but also by interrupting the inflammatory process even decrease B-cell activity and antibody production. In conclusion, our study shows that antibody synthesis in humans is not regulated by a biofeedback mechanism. These findings are in line with similar results found in rabbits and knockout mice.8-11 Administration of cytotoxic drugs for inhibition of a supposed antibody rebound should, therefore, be avoided, because it has no influence on postapheresis synthesis rate but implies an additional risk for the patient.     Acknowledgments The flc Kits were provided by "The Binding Site," Birmingham, England. We thank Professor I.C.M. Maclennan, Birmingham, United Kingdom, and Professor G. Zlabinger, Vienna, Austria, for valuable discussion, and Mrs. Konstantin and Mrs. Czarnecki for excellent technical assistance.     Footnotes Submitted January 16, 2002; accepted February 25, 2002. Prepublished online as Blood First Edition Paper, April 17, 2002; DOI 10.1182/blood- 2002-01-0128. The publication costs of this article were defrayed in part by page charge payment. Therefore, and solely to indicate this fact, this article is hereby marked "advertisement" in accordance with 18 U.S.C. section 1734. Reprints: Martin Haas, Department of Internal Medicine III, Division of Nephrology and Dialysis, University Hospital Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria; e-mail: martin.haas{at}akh-wien.ac.at.     References Top Abstract Introduction Study design Results and discussion References 1. Graf MW, Uhr JW. Regulation of antibody formation by serum antibody. I. Removal of specific antibody by means of immunoadsorption. J Exp Med. 1969;130:1175-1186[Abstract]. 2. Terman DS, Garcia-Rinaldi R, Dannemann B, et al. Specific suppression of antibody rebound after extracorporeal immunoadsorption, I: comparison of single versus combination chemotherapeutic agents. Clin Exp Immunol. 1978;34:32-41[Medline] [Order article via Infotrieve]. 3. Euler HH, Krey U, Schröder O, Löffler H. Membrane plasmapheresis technique in rats. Confirmation of antibody rebound. J Immunol Methods. 1985;84:313-319[CrossRef][Medline] [Order article via Infotrieve]. 4. Reding R, White DJG, Wright LJ, et al. Qualitative analysis of antibody rebound after plasma exchange in the rat. Transplant Proc. 1989;21:777-778[Medline] [Order article via Infotrieve]. 5. Follette DB, Kerr D, Nasca TJ, Euler HH, Pinevich AJ. A method for chronic membrane plasmapheresis in the rat. J Appl Physiol. 1993;75:2820-2824[Abstract/Free Full Text]. 6. Dau PC. Increased proliferation of blood mononuclear cells after plasmapheresis treatment of patients with demyelinating disease. J Neuroimmunol. 1990;30:15-21[CrossRef][Medline] [Order article via Infotrieve]. 7. Dau PC. Increased antibody production in peripheral blood mononuclear cells after plasma exchange therapy in multiple sclerosis. J Neuroimmunol. 1995;62:197-200[CrossRef][Medline] [Order article via Infotrieve]. 8. Charlton B, Schindhelm K, Smeby LC, Farrell PC. Analysis of immunoglobulin G kinetics in the non-steady state. J Lab Clin Med. 1985;105:312-320[Medline] [Order article via Infotrieve]. 9. Charlton B, Schindhelm K. The effect of extracorporeal antibody removal on antibody synthesis and catabolism in immunized rabbits. Clin Exp Immunol. 1985;60:457-464[Medline] [Order article via Infotrieve]. 10. Charlton B, Schindhelm K, Farrell PC. Effect of extracorporeal IgG removal on IgG kinetics. Trans Am Soc Artif Intern Organs. 1983;29:724-729[Medline] [Order article via Infotrieve]. 11. Junghans RP, Anderson CL. The protection receptor for IgG catabolism is the 2-microglobulin-containing intestinal transport receptor. Proc Natl Acad Sci U S A. 1996;93:5512-5516[Abstract/Free Full Text]. 12. Junghans RP. IgG biosynthesis: no "immunoregulatory feedback." Blood. 1997;90:3815-3818[Free Full Text]. 13. Levinson SS, Keren DF. Free light chains of immunoglobulins: clinical laboratory analysis. Clin Chem. 1994;40:1869-1878[Abstract/Free Full Text]. 14. Askonas BA, Williamson AR. Biosynthesis of immunoglobulins. Free light chain as an intermediate in the assembly of G-molecules. Nature. 1966;211:369-372[CrossRef][Medline] [Order article via Infotrieve]. 15. Sølling K. Free light chains of immunoglobulins. Scan J Clin Lab Invest. 1981;41:15-83[Medline] [Order article via Infotrieve]. 16. Mehta PD, Cook SD, Troiano RA, Coyle PK. Increased free light chains in the urine from patients with multiple sclerosis. Neurology. 1991;41:540-544[Abstract/Free Full Text]. 17. Hopper JE, Golbus J, Meyer C, Ferrer GA. Urine free light chains in SLE: clonal markers of B-cell activity and potential link to in vivo secreted Ig. J Clin Immunol. 2000;20:123-137[CrossRef][Medline] [Order article via Infotrieve]. 18. Haas M, Godfrin Y, Oberbauer R, et al. Plasma immunoadsorption treatment in patients with primary focal and segmental glomerulosclerosis. Nephrol Dial Transplant. 1998;13:2013-2016[Abstract/Free Full Text]. 19. Schmaldienst S, Banyai S, Stulnig TM, et al. Prospective randomised cross-over comparison of three LDL-apheresis systems in statine pretreated patients with familial hypercholesterolaemia. Atherosclerosis. 2000;151:493-499[CrossRef][Medline] [Order article via Infotrieve]. 20. Bradwell AR, Carr-Smith HD, Mead GP, et al. Highly sensitive, automated immunoassay for immunoglobulin free light chains in serum and urine. Clin Chem. 2001;47:673-680[Abstract/Free Full Text]. 21. Hopper JE, Sequeira W, Martellotto J, Papagiannes E, Perna L, Skosey JL. Clinical relapse in systemic lupus erythematosus: correlation with antecedent elevation of urinary free light-chain immunoglobulin. J Clin Immunol. 1989;9:338-350[CrossRef][Medline] [Order article via Infotrieve]. 22. Dau PC. Immunologic rebound. J Clin Apheresis. 1995;10:210-217[Medline] [Order article via Infotrieve]. © 2002 by The American Society of Hematology.   CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this? Related Letter in Blood Online: Observing autoimmune patients may not be appropriate for testing "normal" immunoregulatory mechanisms Scott Ely ; and Martin Haas Blood 2002 100: 3055-3056. [Full Text] [PDF] This article has been cited by other articles: A. R. Mezo, K. A. McDonnell, C. A. T. Hehir, S. C. Low, V. J. Palombella, J. M. Stattel, G. D. Kamphaus, C. Fraley, Y. Zhang, J. A. Dumont, et al. Reduction of IgG in nonhuman primates by a peptide antagonist of the neonatal Fc receptor FcRn PNAS, February 19, 2008; 105(7): 2337 - 2342. [Abstract] [Full Text] [PDF] S. Ely ; and M. Haas Observing autoimmune patients may not be appropriate for testing "normal" immunoregulatory mechanisms Blood, September 26, 2002; 100(8): 3055 - 3056. [Full Text] [PDF] This Article Abstract Full Text (PDF) All Versions of this Article: 2002-01-0128v1 100/1/353    most recent Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Rights and Permissions Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Goldammer, A. Articles by Haas, M. 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