Three independent mutations involving the apoptosis-1 (APO-1)/Fas receptor or its putative ligand have led to lupuslike diseases associated with lymphadenopathy in different strains of mice. To determine whether humans with SLE also have a defect in this apoptosis pathway, we analyzed the expression of APO-1 on freshly isolated blood mononuclear cells and on lymphocytes activated in vitro using flow cytometry and the monoclonal antibody anti-APO-1. Significantly higher levels of APO-1 expression were detected on freshly isolated peripheral B cells and both CD4' and CD8' T lymphocyte populations obtained from lupus patients when compared with normal controls (P < 0.001). Almost 90% of the cells that stained positive for APO-1 also expressed the CD29 antigen, suggesting that APO-1 was upregulated after lymphocyte activation in vivo. No defect in APO-1 regulation was detected after activation of SLE T (with anti-CD3) or B (with Staphylococcus aureus Cowan 1) lymphocytes in the presence of IL-2 in vitro. Similarly, the anti-APO-1 antibody induced apoptosis in 74±5% of activated SLE T cells in vitro compared with 79±6% of the normal controls (P > 0.05). These results reveal that, while APO-1 / Fas may play an important role in the regulation of lymphocyte survival in SLE, no consistent defect in the expression or function of the receptor could be detected in these studies. (J. Clin.

Autoantibodies to a polymerase III transcription factor, La (SS-B), are frequently detected in the serum of patients with Sjogren's syndrome and systemic lupus erythematosus. To define the humoral immune response to this protein, we analyzed the patterns of antibody recognition toward 13 recombinant La peptides by immunoblotting and determined the heterogeneity of antibodies reactive with the immunodominant epitopes. The smallest epitopes that were strongly antigenic and recognized by > 70% of sera tested (immunodominant) were encoded by the subclones BgX and XA located in the 5' and 3' halves of the La cDNA, respectively. Conformation of the immunodominant La peptides played a major role in antibody recognition. Although greater diversity in antibody binding to carboxyl-terminal La peptides was observed, the overall pattern of peptide recognition by anti-La antibodies was similar in different diseases. The antibody responses to the immunodominant peptides were strongly correlated (r = 0.68, P < 0.001). One-and two-dimensional isoelectric focusing of affinity purified IgG anti-La peptide antibodies revealed restricted heterogeneity and oligoclonal bands (K light chains). These observations suggest that anti-La antibodies are induced and/or maintained by the self antigen and that their diversity is constrained either by mechanisms related to tolerance or by affinity maturation of the humoral immune response. (J. Clin. Invest. 1990. 85:325-333.) autoantibody -epitope mapping * La (SS-B) * systemic lupus erythematosus

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SUMMARYThis study was undertaken to determine the role of antibodies against both recombinant Ro (r-Ro) and La (r-La) proteins and polypeptides derived from the recombinant La protein in predicting fetal and neonatal outcome in children at risk to develop neonatal lupus erythematosus (NLE). All sera were obtained in the perinatal period and quantitative ELISA assays were used. We collected 41 maternal sera within 2 months of delivery ofa child with NLE (21 with congenital heart disease block (CHB) and 20 with dermalologic NLE) and 19 sera from anti-Ro and/or anti-La antibodypositive mothers with systemic lupus erythematosus (SLE) who delivered a child without NLE. All sera were tested for anti-r-La aod anti-r-Ro antibodies by ELISA, and most sera were tested for antibodies directed against La polypeptides by immunoblot. We found significantly higher anti-rLa antibody levels in the sera from mothers of children with NLE compared with sera from mothers of unaffected children (067 i 0-43 versus 0-14 ± 0-30: P < 0 0001). There was a statistically significant difference in the mean anti-r-La levels between the sera of mothers of children with CHB compared with dermatologic NLE (0-51 ±0 45 versus 083 ±0 37 respectively; /'^O 0091). When we examined antibodies directed against the recombinant 52-kD Ro protein, there was a statistically significant elevation of titres in the sera of mothers of NLE children (0 77±0 35) compared with non-NLE mothers (0'29±0 39; /*

A full-term 9-day-old girl presented with fever, irritability, and seizures. The routine CSF examination, cranial ultrasound, and laboratory tests were normal. Brain MRI showed diffuse white matter abnormality (figure). Human parechovirus (HPeV) type 3 was isolated in both CSF and blood. The neurodevelopmental outcome at 4 months is poor, and MRI shows an extensive cystic leukomalacia in the frontal white matter.The diagnosis of HPeV infection can be made from a positive HPeV PCR in CSF and blood. Extensive white matter abnormality is a typical MRI finding in neonatal HPeV encephalitis, whereas herpes simplex virus encephalitis exhibits diffuse gray and white matter changes. 1 AUTHOR CONTRIBUTIONSVincenzo Belcastro and Paolo Bini: drafting/revising the manuscript for content, including medical writing for content; analysis or interpretation of data; study supervision or coordination. Mario Barbarini and Roberta Barachetti: analysis or interpretation of data; drafting/revising the manuscript for content, including medical writing. STUDY FUNDINGNo targeted funding reported. DISCLOSUREThe authors report no disclosures relevant to the manuscript. Go to Neurology.org for full disclosures. MRI T2-weighted spin-echo axial section (A) shows punctate white matter lesions (arrows) suggestive of petechial hemorrhages. Diffusion-weighted imaging section (B) shows diffuse excessive high signal intensity. This distinctive pattern of white matter involvement is noteworthy, and these abnormalities extend into the subcortical white matter and involve entire fiber tracts, corpus callosum, optic radiation, and posterior thalamus.From the Departments of Neurosciences (V.B.) and Neonatology (P.B., R.B., M.B.), S.

Although proteinase 3 (PR3) has been identified as a major autoantigen in Wegener's granulomatosis, the precise antibody specificity(ies) and requirements for epitope recognition have not been characterized. We analyzed 11 sera containing antineutrophil cytoplasmic antibodies (cANCA) for binding to azurophilic granule proteins extracted from neutrophils under various conditions and for binding to native or rPR3. Ten of 11 (91%) of the cANCA sera bound to PR3 extracted by nonionic detergents when tested by immunoprecipitation or by IEF followed by capillary immunoblotting. Antibody binding to PR3 was retained when IEF was performed under dissociating conditions (8 M urea) indicating that PR3 is the major autoantigen in azurophilic granules and that association with other proteins is not required for antigenicity. In contrast, antigenicity was totally destroyed by exposure of PR3 to reducing agents or to low pH (less than 3.0) and was either lost or considerably diminished after boiling in SDS. cANCA sera also showed little or no binding to rPR3 expressed as a fusion protein in Escherichia coli or synthesized by wheat germ ribosomes in vitro. Inasmuch as PR3 enzymatic activity was partially retained after acid extraction, these findings indicate that cANCA bind to a limited number of conformational epitopes on PR3. In addition, IEF followed by capillary immunoblotting appears to be a sensitive and specific method to detect anti-PR3 antibodies in Wegener's granulomatosis.

We report 2 neonates with human parechoviruses type 3 encephalitis. Both newborns presented with fever, irritability and seizures. Cerebrospinal fluid analyses were normal, but magnetic resonance imaging revealed white matter damage, suggesting human parechoviruse infection. Human parechoviruses type 3-RNA was detected in cerebrospinal fluid samples and in blood, stool, urine and respiratory samples, indicating the dissemination of the virus.

Whole-exome sequencing (WES) is a powerful and comprehensive tool for the genetic diagnosis of rare diseases, but few reports describe its timely application and clinical impact on infantile cardiomyopathies (CM). We conducted a retrospective analysis of patients with infantile CMs who had trio (proband and parents)-WES to determine whether results contributed to clinical management in urgent and non-urgent settings. Twenty-nine out of 42 enrolled patients (69.0%) received a definitive molecular diagnosis. The mean time-to-diagnosis was 9.7 days in urgent settings, and 17 out of 24 patients (70.8%) obtained an etiological classification. In non-urgent settings, the mean time-to-diagnosis was 225 days, and 12 out of 18 patients (66.7%) had a molecular diagnosis. In 37 out of 42 patients (88.1%), the genetic findings contributed to clinical management, including heart transplantation, palliative care, or medical treatment, independent of the patient’s critical condition. All 29 patients and families with a definitive diagnosis received specific counseling about recurrence risk, and in seven (24.1%) cases, the result facilitated diagnosis in parents or siblings. In conclusion, genetic diagnosis significantly contributes to patients’ clinical and family management, and trio-WES should be performed promptly to be an essential part of care in infantile cardiomyopathy, maximizing its clinical utility.