Facial manifestations of Epstein-Barr virus-related lymphoproliferative disease in childhood acute lymphoblastic leukemia in remission: Two atypical presentations.

Epstein-Barr virus-related lymphoproliferative disease (EBV-LPD) rarely occurs in patients with acute lymphoblastic leukemia (ALL), who have not received hematopoietic transplantation. We describe EBV-LPD manifesting as facial lesions in two children with ALL in remission. One patient was a 16-year-old male with T-cell ALL with an EBV-positive angiocentric polymorphous lip lesion presenting as right-sided facial swelling. The other patient was a 12-year-old male with B-cell ALL with an EBV-positive polymorphous lymphoplasmacytic infiltrate presenting as bilateral dacryoadenitis. Neither patient had known primary immunodeficiencies. Both cases improved with immunosuppressant de-escalation. These cases suggest that immunosuppression induced by maintenance chemotherapy is sufficient to promote EBV-LPD.

Pediatric-type nodal follicular lymphoma: an indolent clonal proliferation in children and adults with high proliferation index and no BCL2 rearrangement.

Pediatric follicular lymphoma (PFL) is a variant of follicular lymphoma (FL) presenting as localized lymphadenopathy in children. Unlike conventional adult FL, PFL typically does not recur or progress. Clear diagnostic criteria for PFL are lacking, and it is uncertain whether this indolent lymphoma is defined by age or may occur in adults. We analyzed 27 FL in patients < 40 years of age and found that all 21 cases that lacked a BCL2 gene abnormality (BCL2-N; P < .0001) and had > 30% Ki67 fraction (high proliferation index, HPI; P = .0007) were stage I and did not progress or recur; in comparison, all 6 cases with BCL2 rearrangement and/or PI < 30% were stage III/IV, and 5 of 6 recurred or progressed. In a separate cohort of 58 adult FL (≥ 18 years of age), all 13 BCL2-N/HPI cases were stage I, and none progressed or relapsed, whereas 11 of 15 stage I cases with BCL2 gene abnormality and/or LPI relapsed or progressed (P = .0001). The adult and pediatric BCL2-N/HPI FL cases had similar morphologic features. Our results confirm the highly indolent behavior of PFL and suggest that these are characterized by HPI and absence of BCL2 gene abnormality. PFL-like cases also occur in adults and are associated with indolent behavior in this patient population.

Relapse after treatment of pediatric Hodgkin lymphoma: outcome and role of surveillance after end of therapy.

BACKGROUND: The outcome of treatment for pediatric Hodgkin lymphoma (HL) is excellent using chemotherapy and radiation. However, a minority of patients will relapse after treatment, but additional therapy achieves durable second remission in many cases. The optimal surveillance strategy after modern therapy for HL has not been well defined. PROCEDURES: We reviewed the outcomes of pediatric patients with HL treated between 1990 and 2006 to determine the primary event that led to the detection of relapse. We determined the probability of relapse detection by routine follow-up procedures, including history, physical examination, laboratory tests, and imaging, and determined the impact of each of these screening methods on the likelihood of survival after relapse. RESULTS: Relapse occurred in 64 of 402 evaluable patients (15.9%) at a median of 1.7 years from the time of diagnosis. The majority of relapses (60%) were diagnosed at a routine visit, and patient complaint was the most common initial finding that led to a diagnosis of relapse (47% of relapses). An abnormal finding on physical examination was the primary event in another 17% of relapses, and imaging abnormalities led to the diagnosis in the remaining 36%. Laboratory abnormalities were never the primary finding. The method of detection of relapse and timing (whether detected at a routine visit or an extra visit) did not impact survival. CONCLUSIONS: In pediatric HL, most relapses are identified through history and physical examination. Frequent imaging of asymptomatic patients does not appear to impact survival and is probably not warranted.

Prevalence and prognostic significance of KIT mutations in pediatric patients with core binding factor AML enrolled on serial pediatric cooperative trials for de novo AML.

KIT receptor tyrosine kinase mutations are implicated as a prognostic factor in adults with core binding factor (CBF) acute myeloid leukemia (AML). However, their prevalence and prognostic significance in pediatric CBF AML is not well established. We performed KIT mutational analysis (exon 8 and exon 17) on diagnostic specimens from 203 pediatric patients with CBF AML enrolled on 4 pediatric AML protocols. KIT mutations were detected in 38 (19%) of 203 (95% CI, 14%-25%) patient samples of which 20 (52.5%) of 38 (95% CI, 36%-69%) involved exon 8, 17 (45%) of 38 (95% CI, 29%-62%) involved exon 17, and 1 (2.5%; 95% CI, 0%-14%) involved both locations. Patients with KIT mutations had a 5-year event-free survival of 55% (+/- 17%) compared with 59% (+/- 9%) for patients with wild-type KIT (P = .86). Rates of complete remission, overall survival, disease-free survival, or relapse were not significantly different for patients with or without KIT mutations. Location of the KIT mutation and analysis by cytogenetic subtype [t(8;21) vs inv(16)] also lacked prognostic significance. Our study shows that KIT mutations lack prognostic significance in a large series of pediatric patients with CBF AML. This finding, which differs from adult series and a previously published pediatric study, may reflect variations in therapeutic approaches and/or biologic heterogeneity within CBF AML. Two of 4 studies included in this analysis are registered at http://clinicaltrials.gov as NCT00002798 (CCG-2961) and NCT00070174 (COG AAML03P1).

Association between radiotherapy vs no radiotherapy based on early response to VAMP chemotherapy and survival among children with favorable-risk Hodgkin lymphoma.

CONTEXT: More than 90% of children with favorable-risk Hodgkin lymphoma can achieve long-term survival, yet many will experience toxic effects from radiation therapy. Pediatric oncologists strive for maintaining excellent cure rates while minimizing toxic effects. OBJECTIVE: To evaluate the efficacy of 4 cycles of vinblastine, Adriamycin (doxorubicin), methotrexate, and prednisone (VAMP) in patients with favorable-risk Hodgkin lymphoma who achieve a complete response after 2 cycles and do not receive radiotherapy. DESIGN, SETTING, AND PATIENTS: Multi-institutional, unblinded, nonrandomized single group phase 2 clinical trial to assess the need for radiotherapy based on early response to chemotherapy. Eighty-eight eligible patients with Hodgkin lymphoma stage I and II (<3 nodal sites, no B symptoms, mediastinal bulk, or extranodal extension) enrolled between March 3, 2000, and December 9, 2008. Follow-up data are current to March 12, 2012. INTERVENTIONS: The 47 patients who achieved a complete response after 2 cycles received no radiotherapy, and the 41 with less than a complete response were given 25.5 Gy-involved-field radiotherapy. MAIN OUTCOME MEASURES: Two-year event-free survival was the primary outcome measure. A 2-year event-free survival of greater than 90% was desired, and 80% was considered to be unacceptably low. RESULTS: Two-year event-free survival was 90.8% (95% CI, 84.7%-96.9%). For patients who did not require radiotherapy, it was 89.4% (95% CI, 80.8%-98.0%) compared with 92.5% (95% CI, 84.5%-100%) for those who did (P = .61). Most common acute adverse effects were neuropathic pain (2% of patients), nausea or vomiting (3% of patients), neutropenia (32% of cycles), and febrile neutropenia (2% of patients). Nine patients (10%) were hospitalized 11 times (3% of cycles) for febrile neutropenia or nonneutropenic infection. Long-term adverse effects after radiotherapy were asymptomatic compensated hypothyroidism in 9 patients (10%), osteonecrosis and moderate osteopenia in 2 patients each (2%), subclinical pulmonary dysfunction in 12 patients (14%), and asymptomatic left ventricular dysfunction in 4 patients (5%). No second malignant neoplasms were observed. CONCLUSIONS: Among patients with favorable-risk Hodgkin lymphoma and a complete early response to chemotherapy, the use of limited radiotherapy resulted in a high rate of 2-year event-free survival. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00145600.

Advanced-stage large-cell lymphoma in children and adolescents: results of a randomized trial incorporating intermediate-dose methotrexate and high-dose cytarabine in the maintenance phase of the APO regimen: a Pediatric Oncology Group phase III trial.

PURPOSE: The Pediatric Oncology Group adopted a histology-based approach to non-Hodgkin's lymphoma and treated patients with advanced large-cell lymphoma on a separate protocol (doxorubicin, vincristine, prednisone, 6-mercaptopurin, and methotrexate; APO regimen). In this study, we assessed the effects of an intense antimetabolite therapy alternating with APO on overall survival (OS) and event-free survival (EFS) and looked into biologic correlates. PATIENTS AND METHODS: From December 1994 to April 2000, we enrolled 180 eligible pediatric patients with stage III/IV large-cell lymphoma (LCL); 90 patients were randomly assigned to the intermediate-dose methotrexate (IDM) and high-dose cytarabine (HiDAC) arm, 85 patients to the APO arm, and five patients directly to the APO arm by study design due to CNS involvement. Planned therapy duration was 12 months. RESULTS: The 4-year EFS for all patients was 67.4% (SE, 4.2%), and OS was 80.1% (SE, 3.6%) without any significant difference between the two arms. The 4-year EFS and OS were 71.8% (SE, 6.1%) and 88.1% (SE, 4.4%), respectively, for patients with anaplastic large-cell lymphoma, and 63.8% (SE, 10.3%) and 70.3% (SE, 9.0%), respectively, for patients with diffuse large B-cell lymphoma. Only 11 patients required radiation (due to unresponsive bulky disease or CNS involvement). The IDM/HiDAC arm was associated with more toxicity. CONCLUSION: The efficacy of incorporating IDM/HiDAC in the treatment plan of pediatric and adolescent patients with advanced-stage LCL was inconclusive as to its effect on EFS, regardless of the lymphoma phenotype. It cannot be excluded that with a higher number of patients, one treatment could prove superior and future studies will build on these data.

Treatment of unfavorable childhood Hodgkin's disease with VEPA and low-dose, involved-field radiation.

PURPOSE: Between January 1990 and April 1993, 56 pediatric patients with Hodgkin's disease were treated on a single-arm trial at three institutions with a regimen designed to maintain high cure rates while minimizing the potential late effects of treatment, such as infertility, second malignant neoplasms, and cardiopulmonary injury. PATIENTS AND METHODS: The regimen used combined-modality therapy with six cycles of vinblastine, etoposide, prednisone, and doxorubicin (VEPA) chemotherapy and low-dose, involved-field radiation. Unfavorable features comprised bulky presentations of localized (stage I or II) disease or advanced (stage III or IV) Hodgkin's disease. RESULTS: Of 56 patients enrolled, 26 (46%) had unfavorable presentations of stage I/II disease and 30 (54%) had advanced (stage III/IV) disease. Seventy-nine percent of the patients are alive without disease at a median follow-up time of 8.9 years from diagnosis. Nineteen patients had events at a median of 1.5 years (range, 0.4 to 7.9 years) from diagnosis; 17 patients relapsed, one died of cardiomyopathy, and one died of accidental injuries. Survival and event-free survival (EFS) estimates at 5 years for the entire cohort were 81.9% (SE, 5.2%) and 67.8% (SE, 6.3%), respectively. Five-year EFS by stage was 100% for stage I, 79.2% (SE, 8.3%) for stage II, 70% (SE, 14.5%) for stage III, and 49.5% (SE, 11.3%) for stage IV patients. CONCLUSION: Combined-modality therapy with VEPA chemotherapy and low-dose, involved-field radiation is adequate for disease control of early-stage patients with unfavorable features, but it is inferior to other standard regimens for advanced-stage patients.

VAMP and low-dose, involved-field radiation for children and adolescents with favorable, early-stage Hodgkin's disease: results of a prospective clinical trial.

PURPOSE: To evaluate outcome and assess toxicity of children and adolescents with early-stage, favorable Hodgkin's disease treated with vinblastine, doxorubicin, methotrexate, and prednisone (VAMP) and low-dose, involved-field radiation. PATIENTS AND METHODS: One hundred ten patients with clinical stages I and II, favorable (nonbulky) Hodgkin's disease were treated with four cycles of VAMP chemotherapy and 15 Gy involved-field radiation for those who achieved a complete response, or 25.5 Gy for those who achieved a partial response to two cycles of VAMP. RESULTS: With a median follow-up of 5.6 years (range, 1.1 to 10.4 years), the 5-year survival and event-free survival were 99% (lower confidence limit [CL], 97.4%) and 93% (lower CL, 88.6%), respectively. Factors associated with event-free survival of 100% were complete response to two cycles of VAMP and histology other than nodular sclerosing Hodgkin's disease (NSHD). No serious early or late toxicity has been observed. Patients presenting with clinical stages I and IIA, nonbulky disease involving fewer than three nodal sites have a projected survival and event-free survival of 100% and 97% (lower CL, 93%), respectively, at 5 years. CONCLUSION: Risk-adapted, combined-modality therapy using only four cycles of VAMP chemotherapy with 15 to 25.5 Gy of involved-field radiation for patients with early-stage/favorable Hodgkin's disease is highly effective and without demonstrable late effects. These results indicate that pediatric patients with stages I and II favorable Hodgkin's disease can be cured with limited therapy that does not include an alkylating agent, bleomycin, etoposide, or high-dose, extended-field radiation therapy.

Risk-adapted, combined-modality therapy with VAMP/COP and response-based, involved-field radiation for unfavorable pediatric Hodgkin's disease.

PURPOSE: To evaluate the efficacy of vinblastine, doxorubicin, methotrexate, and prednisone (VAMP) and cyclophosphamide, vincristine, and procarbazine (COP) chemotherapy and response-based, involved-field radiation, a combined-modality regimen that limits doses of alkylating agents, anthracyclines, and radiation, in children with advanced and unfavorable Hodgkin's disease. PATIENTS AND METHODS: From 1993 to 2000, 159 children and adolescents with unfavorable Hodgkin's disease received three alternating cycles (total of six cycles) of VAMP/COP chemotherapy followed by response-based, involved-field radiation therapy: 15 Gy was administered to patients achieving a complete response, and 25.5 Gy was administered to those achieving a partial response after the first two cycles of chemotherapy and to all sites of bulky lymphadenopathy. Unfavorable disease was defined as clinical stage I and II with bulky peripheral nodal disease greater than 6 cm, initial bulky mediastinal mass 33% or more of the intrathoracic diameter, and/or "B" symptoms and all stage III and IV. RESULTS: Study enrollment was closed after an interim analysis estimated a 5-year event-free survival (EFS) rate below a predefined level. Disease presentation was localized (stage I/II) in 77 patients (48.4%) and advanced (stage III/IV) in 82 patients (51.6%). At a median follow-up of 5.8 years (range, 1.3 to 10.0 years), 38 patients had events, including relapse/progression (n = 35), second malignancy (n = 2), and accidental death (n = 1); nine relapses (25.7%) occurred greater than 4 years from diagnosis. Five-year survival and EFS estimates are 92.7% +/- 2.5% and 75.6% +/- 4.1%, respectively. CONCLUSION: Risk-adapted combined-modality therapy with VAMP/COP and response-based, involved-field radiation therapy results in an unsatisfactory outcome for pediatric patients with unfavorable presentations of Hodgkin's disease.

Results of a randomized phase III trial in children and adolescents with advanced stage diffuse large cell non-Hodgkin's lymphoma: a Pediatric Oncology Group study.

PURPOSE: The Pediatric Oncology Group (POG) adopted a histology-based approach to the management of pediatric non-Hodgkin's lymphomas (NHL) utilizing the National Cancer Institute Working Formulation for Clinical Usage. Patients with diffuse large cell lymphoma (DLCL) were treated on a separate protocol from small cell diffuse undifferentiated or lymphoblastic lymphomas. This study assessed the overall and event free survival of children with DLCL and determined the effects of cyclophosphamide upon these end-points in a prospective randomized trial. PATIENTS AND METHODS: One hundred and twenty eligible stage III or IV NHL patients with the confirmed diagnosis of diffuse large cell or immunoblastic histology were enrolled on study between October 1986 and November 1991. Patients were randomized to receive or not receive cyclophosphamide: 58 received cyclophosphamide, doxorubicin, vincristine, 6-mercaptopurine (6-MP), and prednisone (ACOP+) and 62 were treated with doxorubicin, vincristine, 6-MP, and prednisone (APO). In both treatment programs methotrexate was substituted when the doxorubicin cumulative dose reached 450 mg/m2. Radiation was administered to bulky disease if progression or no response were observed after induction therapy. Planned duration of therapy was 12 months. RESULTS: The 5-year event free survival (EFS) rates of patients treated with ACOP+ versus APO were 62+/-7 and 72+/-6%, respectively. While there was no statistically significant difference between the two treatment arms (p = 0.28), we can only say that we are 95% confident that the difference in 5-year EFS falls in the wide range from 28% in favor of APO to 8% favoring ACOP+. Marrow suppression was the main toxicity with one fatal infection. There were three other deaths on study due to respiratory failure in patients with mediastinal masses. Only one patient experienced cardiotoxicity requiring discontinuation of doxorubicin. Ten patients received radiation therapy to achieve remission. CONCLUSION: The efficacy of elimination of cyclophosphamide from the treatment program of children and adolescents with advanced stage diffuse large cell lymphoma was inconclusive as to its effect on EFS. Furthermore, the majority of the patients (92%) did not require any radiation therapy to bulky disease indicating that the chemotherapy regimens are quite efficient for achievement of complete remission.

Final results of a prospective clinical trial with VAMP and low-dose involved-field radiation for children with low-risk Hodgkin's disease.

PURPOSE: To evaluate outcome and assess complications in children and adolescents with low-risk Hodgkin's disease treated with vinblastine, doxorubicin, methotrexate, and prednisone (VAMP) chemotherapy and low-dose, involved-field radiation therapy (IFRT). PATIENTS AND METHODS: One hundred ten children with low-risk Hodgkin's disease were treated with four cycles of VAMP and 15 Gy IFRT for those who achieved a complete response (CR) or 25.5 Gy for those with a partial response after two cycles of VAMP. RESULTS: With median follow-up of 9.6 years (range, 1.7 to 15.0), 5- and 10-year overall survival were 99.1% and 96.1%, respectively, and 5-and 10-year event-free survival (EFS) were 92.7% and 89.4%. Factors contributing to 10-year EFS were: early CR (P = .02), absence of B symptoms (P = .01), lymphocyte predominant histologic subtype (P = .04), and less than three initial sites of disease (P = .02). Organ toxicity has been limited to correctable hypothyroidism in 42% of irradiated patients, and one case of cardiac dysfunction. Seventeen healthy babies have been born to 106 survivors. There have been two malignant tumors: one thyroid cancer within the radiation therapy field and one Ewing's sarcoma outside the radiation therapy field. CONCLUSION: Risk-adapted, combined-modality therapy using VAMP chemotherapy with radiation is effective and well tolerated. Pediatric patients with low-risk Hodgkin's disease can be cured with therapy without an alkylating agent, bleomycin, etoposide, or high-dose, extended-field radiotherapy. Thus, these children are expected to retain normal fertility, organ function, and be at low risk of a second malignant tumor.

A prospective study of the natural history of transient leukemia (TL) in neonates with Down syndrome (DS): Children's Oncology Group (COG) study POG-9481.

A unique transient leukemia (TL) has been described in newborns with Down syndrome (DS; or trisomy 21 mosaics). This leukemia has a high incidence of spontaneous remission; however, early death and subsequent development of acute megakaryoblastic leukemia (AMKL) have been reported. We prospectively evaluated 48 infants with DS and TL to determine the natural history and biologic characteristics of this disease, identify the clinical characteristics associated with early death or subsequent leukemia, and assess the incidence of subsequent leukemia. Blast cells associated with TL in DS infants exhibited FAB M(7) morphology and phenotype. Most infants (74%) had trisomy 21 (or mosaicism) as the only cytogenetic abnormality in the blast cells. Most children were able to spontaneously clear peripheral blasts (89%), normalize blood counts (74%), and maintain a complete remission (64%). Early death occurred in 17% of infants and was significantly correlated with higher white blood cell count at diagnosis (P < .001), increased bilirubin and liver enzymes (P < .005), and a failure to normalize the blood count (P = .001). Recurrence of leukemia occurred in 19% of infants at a mean of 20 months. Development of leukemia was significantly correlated with karyotypic abnormalities in addition to trisomy 21 (P = .037). Ongoing collaborative clinical studies are needed to determine the optimal role of chemotherapy for infants at risk for increased mortality or disease recurrence and to further the knowledge of the unique biologic features of this TL.

Differential gene expression, GATA1 target genes, and the chemotherapy sensitivity of Down syndrome megakaryocytic leukemia.

Children with Down syndrome (DS) with acute megakaryocytic leukemia (AMkL) have very high survival rates compared with non-DS AMkL patients. Somatic mutations identified in the X-linked transcription factor gene, GATA1, in essentially all DS AMkL cases result in the synthesis of a shorter (40 kDa) protein (GATA1s) with altered transactivation activity and may lead to altered expression of GATA1 target genes. Using the Affymetrix U133A microarray chip, we identified 551 differentially expressed genes between DS and non-DS AMkL samples. Transcripts for the bone marrow stromal-cell antigen 2 (BST2) gene, encoding a transmembrane glycoprotein potentially involved in interactions between leukemia cells and bone marrow stromal cells, were 7.3-fold higher (validated by real-time polymerase chain reaction) in the non-DS compared with the DS group. Additional studies confirmed GATA1 protein binding and transactivation of the BST2 promoter; however, stimulation of BST2 promoter activity by GATA1s was substantially reduced compared with the full-length GATA1. CMK sublines, transfected with the BST2 cDNA and incubated with HS-5 bone marrow stromal cells, exhibited up to 1.7-fold reduced cytosine arabinoside (ara-C)-induced apoptosis, compared with mock-transfected cells. Our results demonstrate that genes that account for differences in survival between DS and non-DS AMkL cases may be identified by microarray analysis and that differential gene expression may reflect relative transactivation capacities of the GATA1s and full-length GATA1 proteins.

Pediatric non-Hodgkin's lymphoma: clinical and biologic prognostic factors and risk allocation.

The use of effective combination chemotherapy for all stages and subtypes of non-Hodgkin"s lymphoma (NHL) in children has resulted in a striking improvement in cure rates. Event-free survival now ranges from 70% to 90%, depending on the stage of disease and the NHL subtype. Risk-adapted therapy has resulted in a dramatic improvement in outcome for high-risk patients, at the cost of significantly increased short-term toxicity, and a reduction of therapy and toxicity for the lower-risk patient, while maintaining the excellent cure rate. Successful risk allocation of patients is dependent on the identification and continual validation of prognostic factors. The specific treatment protocol is the single most important factor predicting outcome today. Traditional prognostic factors such as stage and tumor burden are useful in selecting the intensity and length of therapy, rather than as a major indicator of likelihood of survival. In order to further improve cure rates and decrease toxicity, new biologic prognosticators need to be found and validated. Some promising avenues for study appear to be the presence or absence of adhesion molecules and of aberrant proteins that are specific to subtypes of lymphomas, such as soluble CD30 and anaplastic lymphoma kinase (ALK), the molecular classification of lymphomas on the basis of gene expression, and the evaluation of biologic markers for measuring early response to therapy.

Incidence and treatment of potentially lethal diseases in transient leukemia of Down syndrome: Pediatric Oncology Group Study.

Transient leukemia (TL or transient myeloproliferative disorder) occurs in approximately 10% of newborn infants with Down syndrome. The disorder is characterized by the presence of megakaryoblasts in the peripheral blood; most cases resolve spontaneously within the first 3 months of life, and the child is well thereafter. However, there are cases in which a severe, potentially lethal form of disease develops, manifesting as hepatic fibrosis or cardiopulmonary failure. Hitherto, the incidence of these severe forms of the disease has not been reported. A prospective study of TL was conducted by the Pediatric Oncology Group (POG Study 9481) in which 48 children with TL were identified. Life-threatening disease occurred in nine patients (19%); seven had hepatic fibrosis and two had cardiopulmonary failure. Five children died of the disease within the first 3 months of life, none of whom received antileukemic therapy. One patient died on day 31 after receiving minimal therapy within 1 day of death. Three children received low-dose cytosine arabinoside (Ara-C) (0.4-1.5 mg/kg every 12 hours for 5 or 7 days). In all these patients, the disease resolved. It is concluded that potentially lethal disease is relatively common in TL, and the available evidence suggests that these diseases are responsive to low-dose Ara-C therapy.

Rituximab therapy for multisystem autoimmune diseases in pediatric patients.

OBJECTIVE: To evaluate the effects of rituximab (anti-CD20 monoclonal antibody) on the disease course in pediatric patients with multisystem autoimmune diseases. METHODS: Four patients with multisystem autoimmune diseases refractory to conventional immunosuppressive medications, each with central nervous system (CNS) involvement, were treated with four weekly infusions of rituximab. Their clinical and laboratory responses were evaluated. RESULTS: Each of the patients had improvement in clinical symptoms and laboratory parameters. One patient with autoimmune cytopenias and autoimmune CNS and peripheral nervous system disease had resolution of the cytopenias and marked improvement in neurologic symptoms; he currently receives no immunosuppressive medications. Two half-siblings with lymphoplasmacytic colitis, pulmonary nodules, and CNS disease had improvement of their symptoms. A fourth patient with chorea and seizures secondary to primary antiphospholipid antibody syndrome had improvement in fine and gross motor function and reduced seizure frequency. There were no serious adverse events. CONCLUSIONS: The biologic response modifier rituximab, designed to eliminate B lymphocytes, was safe and effective in four pediatric patients with multisystem autoimmune disorders. It appears to be beneficial in autoimmune conditions presumably mediated by a variety of B-cell-related mechanisms, and may decrease or eliminate the need for other immunosuppressive medications.