The spectrum of apoptotic defects and clinical manifestations, including systemic lupus erythematosus, in humans with CD95 (Fas/APO-1) mutations

OBJECTIVE

To determine the clinical spectrum of disease in humans with mutations in the CD95 (Fas/ APO-1) receptor and to obtain mechanistic insight into the different clinical phenotypes observed.

METHODS

Clinical information for each of the index cases, first-degree relatives, and any family members reported to have Canale-Smith syndrome (or another autoimmune disease) was gathered by direct interview, chart review, and verification of data by the physician or pathologist concerned. Apoptosis of activated T or B lymphocytes was induced by agonistic anti-CD95 antibodies and quantified by a cell death assay (propidium iodide staining in the subdiploid peak) or cell viability assay (alamar blue or 3H-thymidine incorporation).

RESULTS

Evaluation of an additional 8 probands with novel heterozygous CD95 mutations revealed hypergammaglobulinemia and immune-mediated cytopenias in all patients, as well as urticarial rash, oral ulceration, lymphopenia, and peripheral neuropathy in some individuals. One patient (P4) had systemic lupus erythematosus (SLE) characterized by a World Health Organization class V lupus nephropathy, a recurrent, reversible multifocal central nervous system disorder, high-titer antiphospholipid autoantibodies, and autoimmune cytopenias. In the P4 pedigree, the father had reduced T and B cell apoptosis associated with a CD95 mutation, whereas an independent B cell apoptotic defect was demonstrated in maternal family members who did not have a CD95 mutation. Three cases of B cell lymphoma occurred in carriers of the CD95 mutation.

CONCLUSIONS

CD95 mutations are associated with loss of regulation of B lymphocytes, which predisposes to systemic autoimmunity including SLE. The P4 family provides a model of the complex genetic and functional interactions that are required for the development of a lupus-like syndrome.

The spectrum of apoptotic defects and clinical manifestations, including systemic lupus erythematosus, in humans with CD95 (Fas/APO-1) mutations

OBJECTIVE

To determine the clinical spectrum of disease in humans with mutations in the CD95 (Fas/ APO-1) receptor and to obtain mechanistic insight into the different clinical phenotypes observed.

METHODS

Clinical information for each of the index cases, first-degree relatives, and any family members reported to have Canale-Smith syndrome (or another autoimmune disease) was gathered by direct interview, chart review, and verification of data by the physician or pathologist concerned. Apoptosis of activated T or B lymphocytes was induced by agonistic anti-CD95 antibodies and quantified by a cell death assay (propidium iodide staining in the subdiploid peak) or cell viability assay (alamar blue or 3H-thymidine incorporation).

RESULTS

Evaluation of an additional 8 probands with novel heterozygous CD95 mutations revealed hypergammaglobulinemia and immune-mediated cytopenias in all patients, as well as urticarial rash, oral ulceration, lymphopenia, and peripheral neuropathy in some individuals. One patient (P4) had systemic lupus erythematosus (SLE) characterized by a World Health Organization class V lupus nephropathy, a recurrent, reversible multifocal central nervous system disorder, high-titer antiphospholipid autoantibodies, and autoimmune cytopenias. In the P4 pedigree, the father had reduced T and B cell apoptosis associated with a CD95 mutation, whereas an independent B cell apoptotic defect was demonstrated in maternal family members who did not have a CD95 mutation. Three cases of B cell lymphoma occurred in carriers of the CD95 mutation.

CONCLUSIONS

CD95 mutations are associated with loss of regulation of B lymphocytes, which predisposes to systemic autoimmunity including SLE. The P4 family provides a model of the complex genetic and functional interactions that are required for the development of a lupus-like syndrome.

Intellectual function in long-term survivors of childhood acute lymphoblastic leukemia: protective effect of pre-irradiation methotrexate? A Childrens Cancer Study Group study

Having demonstrated in a laboratory model that the neurotoxicity of CNS irradiation can be ameliorated with pre-irradiation methotrexate, we retrospectively compared two methods of CNS prophylaxis in childhood acute lymphoblastic leukemia which differed only in the timing of intrathecal methotrexate and radiotherapy. The results of standard IQ tests conducted 2-11 years after 24 Gy of cranial radiotherapy were obtained in 72 patients, of whom 27 had pre-irradiation methotrexate and 45 did not (control group). The two groups were otherwise comparable. In girls, the full-, performance-, and verbal-scale IQ scores were consistently higher in the pre-irradiation methotrexate group than in the corresponding control group (P less than 0.025). Among girls less than 5 years of age when irradiated, the mean IQ scores were 25-29 points higher after pre-irradiation methotrexate than after the control treatment (P less than 0.0007). These results suggest that pre-irradiation methotrexate may help prevent CNS radiotoxicity in children, and that the benefit is dependent on patient age and gender.

Marrow hypoplasia associated with congenital neurologic anomalies in two siblings

Two siblings with congenital neurologic structural anomalies and delayed-onset selective bone marrow hypoplasia in a previously undescribed constellation of symptoms are presented. Differences between these cases and other well known syndromes are discussed. The importance of this association is the implication that children with congenital neurologic abnormalities may be at increased risk for the development of hypoplastic hematopoietic conditions.

Influence of age, sex, and concurrent intrathecal methotrexate therapy on intellectual function after cranial irradiation during childhood: a report from the Children's Cancer Study Group

Standard IQ tests were performed in 70 children and adolescents 3.5-10 years (median 5 yrs) after 24 Gy cranial irradiation, with or without concurrent intrathecal methotrexate, for central nervous system prophylaxis of acute lymphoblastic leukemia. Lower IQ scores correlated with younger age, female gender, and concomitant intrathecal methotrexate therapy. Multivariate analysis identified age as the most important determinant of the three factors. The lowest IQ scores were observed in girls who were less than 5 years old at the time of irradiation and who received concurrent intrathecal methotrexate. The observed adverse contribution of simultaneous intrathecal methotrexate therapy on IQ outcome may have significant implications for school performance, peer relationships, and occupational expectations.

Prediction of intellectual deficits in children with acute lymphoblastic leukemia

Possible predictors of reported lower cognitive functioning in irradiated children with acute lymphoblastic leukemia (ALL) were investigated. Thirty-four subjects, 5-14 years old, with ALL in continuous complete remission and without evidence of current or past central nervous system disease, were examined 9-110 months after diagnosis, using standard measures of intelligence and academic achievement. Subjects with a history of post-irradiation somnolence syndrome were significantly older at diagnosis than nonsomnolent subjects. Intelligence (IQ) was found to be unrelated to history of somnolence syndrome. IQ and achievement were unrelated to age at irradiation, irradiation-examination interval, and radiation dosages. The strongest predictor of IQ by far is parental social class. The importance of controlling for social class differences when searching for treatment effects on IQ and achievement is stressed.