Limits...
Long-lived plasma cells and memory B cells produce pathogenic anti-GAD65 autoantibodies in Stiff Person Syndrome.

Rizzi M, Knoth R, Hampe CS, Lorenz P, Gougeon ML, Lemercier B, Venhoff N, Ferrera F, Salzer U, Thiesen HJ, Peter HH, Walker UA, Eibel H - PLoS ONE (2010)

Bottom Line: Studying the B cell compartment and the anti-GAD65 B cell response in two monozygotic twins suffering from SPS, who were treated with the B cell-depleting monoclonal anti-CD20 antibody rituximab, we found that the humoral autoimmune response in SPS is composed of a rituximab-sensitive part that is rapidly cleared after treatment, and a rituximab-resistant component, which persists and acts as a reservoir for autoantibodies inhibiting GAD65 enzyme activity.Both subsets represent only a fraction of anti-GAD65 autoantibody secreting cells.Therefore, the identification and targeting of this compartment is a key factor for successful treatment planning of SPS and of similar autoimmune diseases.

View Article: PubMed Central - PubMed

Affiliation: Department of Rheumatology and Clinical Immunology, University Medical Center Freiburg, Freiburg, Germany.

ABSTRACT
Stiff person syndrome (SPS) is a rare, neurological disorder characterized by sudden cramps and spasms. High titers of enzyme-inhibiting IgG autoantibodies against the 65 kD isoform of glutamic acid decarboxylase (GAD65) are a hallmark of SPS, implicating an autoimmune component in the pathology of the syndrome. Studying the B cell compartment and the anti-GAD65 B cell response in two monozygotic twins suffering from SPS, who were treated with the B cell-depleting monoclonal anti-CD20 antibody rituximab, we found that the humoral autoimmune response in SPS is composed of a rituximab-sensitive part that is rapidly cleared after treatment, and a rituximab-resistant component, which persists and acts as a reservoir for autoantibodies inhibiting GAD65 enzyme activity. Our data show that these potentially pathogenic anti-GAD65 autoantibodies are secreted by long-lived plasma cells, which may either be persistent or develop from rituximab-resistant memory B lymphocytes. Both subsets represent only a fraction of anti-GAD65 autoantibody secreting cells. Therefore, the identification and targeting of this compartment is a key factor for successful treatment planning of SPS and of similar autoimmune diseases.

Show MeSH

Related in: MedlinePlus

A portion of antibodies in SPS patients is not influenced by rituximab treatment.Rituximab treatment induces a 2-fold decrease of GAD65 specific serum antibody titer. (A) Serum samples from twin A and twin B were collected before and 8, 16, 36 weeks after rituximab treatment, and GAD65 specific antibody titers were measured by ELISA. The titers of 8 healthy donors ranged between undetectable and 1/80. (B) Inhibition of GAD65 enzyme activity was tested with IgG of twin A and twin B isolated at week 0 and 36 after starting the anti-CD20 treatment. (C,D) TT and Rotavirus antibody titers. Serum from twin A and twin B was collected at week 0 and 36 post rituximab treatment, and antibody titer was measured by ELISA. Eight healthy donors (HD) were used as controls. (E, F) Pneumococcal polysaccharide (PnP) antigens antibody titers in twin A (E) and in twin B serum (F), at week 0 and 36 post treatment, x axes show the different PnP antigens tested.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2877104&req=5

pone-0010838-g001: A portion of antibodies in SPS patients is not influenced by rituximab treatment.Rituximab treatment induces a 2-fold decrease of GAD65 specific serum antibody titer. (A) Serum samples from twin A and twin B were collected before and 8, 16, 36 weeks after rituximab treatment, and GAD65 specific antibody titers were measured by ELISA. The titers of 8 healthy donors ranged between undetectable and 1/80. (B) Inhibition of GAD65 enzyme activity was tested with IgG of twin A and twin B isolated at week 0 and 36 after starting the anti-CD20 treatment. (C,D) TT and Rotavirus antibody titers. Serum from twin A and twin B was collected at week 0 and 36 post rituximab treatment, and antibody titer was measured by ELISA. Eight healthy donors (HD) were used as controls. (E, F) Pneumococcal polysaccharide (PnP) antigens antibody titers in twin A (E) and in twin B serum (F), at week 0 and 36 post treatment, x axes show the different PnP antigens tested.

Mentions: Two monozygotic twins affected by SPS were treated with 2 single 1000 mg injections of rituximab at 2 weeks of interval, however during 1 year of follow-up clinical improvements were not observed [21]. Before receiving rituximab-treatment, both patients had an elevated percentage of circulating B cells (22% and 21% CD19+ cells in twin A and B, respectively, normal range 5–18%) with a normal distribution of naïve and memory B cells as well as plasmablasts (Table 1). Eight and 18 weeks after rituximab treatment, CD19+ B cells were undetectable in peripheral blood. In line with previously published data [22], [23], the B cell compartment in peripheral blood was partially regenerated 36 weeks after rituximab and returned to pre-treatment values at week 54, however with a predominance of naïve and transitional B cell subsets (>95% and >8% respectively). The percentages of class switched memory and marginal zone B cells were both reduced 4 to 5-fold compared to pre-treatment values, whereas the proportion of plasmablasts increased from 1.06% to 1.72% in twin A and from 0.5% to 1% in twin B (Table 1). During the entire monitoring period the total serum IgG concentration remained constant [21]. Twin A and twin B had initially very high anti-GAD65 antibody serum titers (1/256,000), exceeding the titers of control sera by 10,000-fold (average 1/40, range: not detectable to 1/80; n = 8). Despite the fact that a 2-fold decline in anti-GAD65 antibody titer to 1/128,000 was observed in both patients 8 weeks after anti-CD20 treatment and persisted up to week 36, the titers remained at least 2,000-fold above the controls (Fig. 1A). These data indicate that only about half of anti-GAD65 antibodies are sensitive to anti-CD20 mediated B cell depletion. Similar to the anti-GAD65 serum titers the IgG concentrations of antibodies specific for TT, rotavirus group A antigen and S. pneumoniae cell wall (PnPs) antigens either remained unchanged or increased upon rituximab treatment (Fig. 1 C–F).


Long-lived plasma cells and memory B cells produce pathogenic anti-GAD65 autoantibodies in Stiff Person Syndrome.

Rizzi M, Knoth R, Hampe CS, Lorenz P, Gougeon ML, Lemercier B, Venhoff N, Ferrera F, Salzer U, Thiesen HJ, Peter HH, Walker UA, Eibel H - PLoS ONE (2010)

A portion of antibodies in SPS patients is not influenced by rituximab treatment.Rituximab treatment induces a 2-fold decrease of GAD65 specific serum antibody titer. (A) Serum samples from twin A and twin B were collected before and 8, 16, 36 weeks after rituximab treatment, and GAD65 specific antibody titers were measured by ELISA. The titers of 8 healthy donors ranged between undetectable and 1/80. (B) Inhibition of GAD65 enzyme activity was tested with IgG of twin A and twin B isolated at week 0 and 36 after starting the anti-CD20 treatment. (C,D) TT and Rotavirus antibody titers. Serum from twin A and twin B was collected at week 0 and 36 post rituximab treatment, and antibody titer was measured by ELISA. Eight healthy donors (HD) were used as controls. (E, F) Pneumococcal polysaccharide (PnP) antigens antibody titers in twin A (E) and in twin B serum (F), at week 0 and 36 post treatment, x axes show the different PnP antigens tested.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2877104&req=5

pone-0010838-g001: A portion of antibodies in SPS patients is not influenced by rituximab treatment.Rituximab treatment induces a 2-fold decrease of GAD65 specific serum antibody titer. (A) Serum samples from twin A and twin B were collected before and 8, 16, 36 weeks after rituximab treatment, and GAD65 specific antibody titers were measured by ELISA. The titers of 8 healthy donors ranged between undetectable and 1/80. (B) Inhibition of GAD65 enzyme activity was tested with IgG of twin A and twin B isolated at week 0 and 36 after starting the anti-CD20 treatment. (C,D) TT and Rotavirus antibody titers. Serum from twin A and twin B was collected at week 0 and 36 post rituximab treatment, and antibody titer was measured by ELISA. Eight healthy donors (HD) were used as controls. (E, F) Pneumococcal polysaccharide (PnP) antigens antibody titers in twin A (E) and in twin B serum (F), at week 0 and 36 post treatment, x axes show the different PnP antigens tested.
Mentions: Two monozygotic twins affected by SPS were treated with 2 single 1000 mg injections of rituximab at 2 weeks of interval, however during 1 year of follow-up clinical improvements were not observed [21]. Before receiving rituximab-treatment, both patients had an elevated percentage of circulating B cells (22% and 21% CD19+ cells in twin A and B, respectively, normal range 5–18%) with a normal distribution of naïve and memory B cells as well as plasmablasts (Table 1). Eight and 18 weeks after rituximab treatment, CD19+ B cells were undetectable in peripheral blood. In line with previously published data [22], [23], the B cell compartment in peripheral blood was partially regenerated 36 weeks after rituximab and returned to pre-treatment values at week 54, however with a predominance of naïve and transitional B cell subsets (>95% and >8% respectively). The percentages of class switched memory and marginal zone B cells were both reduced 4 to 5-fold compared to pre-treatment values, whereas the proportion of plasmablasts increased from 1.06% to 1.72% in twin A and from 0.5% to 1% in twin B (Table 1). During the entire monitoring period the total serum IgG concentration remained constant [21]. Twin A and twin B had initially very high anti-GAD65 antibody serum titers (1/256,000), exceeding the titers of control sera by 10,000-fold (average 1/40, range: not detectable to 1/80; n = 8). Despite the fact that a 2-fold decline in anti-GAD65 antibody titer to 1/128,000 was observed in both patients 8 weeks after anti-CD20 treatment and persisted up to week 36, the titers remained at least 2,000-fold above the controls (Fig. 1A). These data indicate that only about half of anti-GAD65 antibodies are sensitive to anti-CD20 mediated B cell depletion. Similar to the anti-GAD65 serum titers the IgG concentrations of antibodies specific for TT, rotavirus group A antigen and S. pneumoniae cell wall (PnPs) antigens either remained unchanged or increased upon rituximab treatment (Fig. 1 C–F).

Bottom Line: Studying the B cell compartment and the anti-GAD65 B cell response in two monozygotic twins suffering from SPS, who were treated with the B cell-depleting monoclonal anti-CD20 antibody rituximab, we found that the humoral autoimmune response in SPS is composed of a rituximab-sensitive part that is rapidly cleared after treatment, and a rituximab-resistant component, which persists and acts as a reservoir for autoantibodies inhibiting GAD65 enzyme activity.Both subsets represent only a fraction of anti-GAD65 autoantibody secreting cells.Therefore, the identification and targeting of this compartment is a key factor for successful treatment planning of SPS and of similar autoimmune diseases.

View Article: PubMed Central - PubMed

Affiliation: Department of Rheumatology and Clinical Immunology, University Medical Center Freiburg, Freiburg, Germany.

ABSTRACT
Stiff person syndrome (SPS) is a rare, neurological disorder characterized by sudden cramps and spasms. High titers of enzyme-inhibiting IgG autoantibodies against the 65 kD isoform of glutamic acid decarboxylase (GAD65) are a hallmark of SPS, implicating an autoimmune component in the pathology of the syndrome. Studying the B cell compartment and the anti-GAD65 B cell response in two monozygotic twins suffering from SPS, who were treated with the B cell-depleting monoclonal anti-CD20 antibody rituximab, we found that the humoral autoimmune response in SPS is composed of a rituximab-sensitive part that is rapidly cleared after treatment, and a rituximab-resistant component, which persists and acts as a reservoir for autoantibodies inhibiting GAD65 enzyme activity. Our data show that these potentially pathogenic anti-GAD65 autoantibodies are secreted by long-lived plasma cells, which may either be persistent or develop from rituximab-resistant memory B lymphocytes. Both subsets represent only a fraction of anti-GAD65 autoantibody secreting cells. Therefore, the identification and targeting of this compartment is a key factor for successful treatment planning of SPS and of similar autoimmune diseases.

Show MeSH
Related in: MedlinePlus