A dose-escalation study of rituximab for treatment of systemic lupus erythematosus and Evans' syndrome: immunological analysis of B cells, T cells and cytokines.
OBJECTIVE
Accumulating evidence suggests that B-cell depletion therapy by rituximab may be effective for autoimmune disorders. However, an optimal dose of rituximab and a mechanism of its action remain to be established. We performed a dose-escalation study for treatment of Japanese patients with autoimmune diseases including eight with SLE and one with Evans' syndrome.


METHODS
Rituximab was infused intravenously, weekly 4 times in a dose-escalating fashion at three different doses of 100, 250 or 375 mg/m(2) to three patients each. Immunological parameters were monitored at certain points until 12 months after the treatment.


RESULTS
Rituximab was well tolerated and safe in these patients. Seven out of eight SLE patients and one with Evans' syndrome clinically responded completely or partially to the treatment. Four patients achieved long-term remission (18-30 months) without any additional treatment. In these patients, a significant decrease in circulating B cells continued for 6 months after the treatment. The mean fluorescence intensities of CD19, CD21, CD40 and BR3 on the residual B cells as well as the percentage of CD69+ CD4+ T cells decreased significantly. Serum TNF-alpha levels decreased significantly on day 2. The Th1/Th2 balance of CD4+ T cells gradually shifted towards a Th1 type by 6 months.


CONCLUSIONS
In addition to B-cell depletion, modification of B-cell and T-cell phenotypes as well as cytokine profiles may be involved in the action of rituximab.
Tamimoto
Y
Y
Department of Medicine and Biosystemic Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan.
Horiuchi
T
T
Tsukamoto
H
H
Otsuka
J
J
Mitoma
H
H
Kimoto
Y
Y
Nakashima
H
H
Muta
K
K
Abe
Y
Y
Kiyohara
C
C
Ueda
A
A
Nagasawa
K
K
Yoshizawa
S
S
Shimoda
T
T
Harada
M
M
D000328:Adult; D000744:Anemia, Hemolytic, Autoimmune / Q000188:drug therapy* / Q000276:immunology; D000911:Antibodies, Monoclonal / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use; D058846:Antibodies, Monoclonal, Murine-Derived; D000954:Antigens, Surface / Q000378:metabolism; D016175:B-Lymphocyte Subsets / Q000187:drug effects* / Q000276:immunology; D016207:Cytokines / Q000097:blood; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use; D008180:Lupus Erythematosus, Systemic / Q000188:drug therapy* / Q000276:immunology; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D000069283:Rituximab; D016176:T-Lymphocyte Subsets / Q000187:drug effects* / Q000276:immunology; D018417:Th1 Cells / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology
D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; D000954:Antigens, Surface; D016207:Cytokines; D007166:Immunosuppressive Agents; D000069283:Rituximab