Trasplante de médula ósea haploidéntico en un paciente pediátrico con síndrome de Wiskott-Aldrich. A propósito de un caso / Haploidentical bone marrow transplantation in a pediatric patient with Wiskott-Aldrich syndrome. A case report

El síndrome de Wiskott-Aldrich es un error innato de la inmunidad de herencia ligada al cromosoma X, producido por variantes en el gen que codifica la proteína del síndrome de Wiskott-Aldrich (WASp). Reportamos el caso clínico de un paciente de 18 meses con diagnóstico de Wiskott-Aldrich que no presentaba donante antígeno leucocitario humano (HLA) idéntico y recibió un trasplante de células progenitoras hematopoyéticas (TCPH) con donante familiar haploidéntico. La profilaxis para enfermedad de injerto contra huésped incluyó ciclofosfamida (PT-Cy). El quimerismo del día +30 fue 100 % del donante y la evaluación postrasplante de la expresión de la proteína WAS fue normal. Actualmente, a 32 meses del trasplante, presenta reconstitución hematológica e inmunológica y quimerismo completo sin evidencia de enfermedad injerto contra huésped. El TCPH haploidéntico con PT-Cy se mostró factible y seguro en este caso de síndrome de WiskottAldrich en el que no se disponía de un donante HLA idéntico.

Wiskott-Aldrich syndrome (WAS) is an X-linked genetic disorder caused by mutations in the gene that encodes the Wiskott-Aldrich syndrome protein (WASp). Here, we report the clinical case of an 18-month-old boy diagnosed with Wiskott-Aldrich syndrome, who did not have an HLA-matched related or unrelated donor and was treated successfully with a hematopoietic stem cell transplant (HSCT) from a haploidentical family donor. Graft-versus-host disease (GvHD) prophylaxis included post-transplant cyclophosphamide (PT-Cy). At day +30, the peripheral blood-nucleated cell chimerism was 100% and the WAS protein had a normal expression. Currently, at month 32 post-transplant, the patient has hematological and immune reconstitution and complete donor chimerism without evidence of GvHD. HSCT with PT-Cy was a feasible and safe option for this patient with WAS, in which an HLA matched donor was not available.

Paciente con diagnóstico de Wiskott Aldrich y presencia de una nueva mutación

RESUMEN Introducción: El síndrome de Wiskott-Aldrich, es una inmunodeficiencia primaria, poco frecuente heredada de forma recesiva ligado al cromosoma X. Está asociado a fenotipos clínicos variables que se correlacionan con el tipo de mutación presente en la proteína del síndrome de Wiskott-Aldrich. Objetivo: Examinar el caso de un paciente con diagnóstico de Wiskott Aldrich y presencia de una mutación no descrita anteriormente. Presentación del caso: Paciente masculino cuya sintomatología se inició a los tres meses de edad, con infecciones respiratorias recurrentes, lesiones purpúricas hemorrágicas tipo equimosis, eccema y plaquetopenia. El diagnóstico se confirmó al año de inicio de los síntomas con la detección de una mutación no descrita anteriormente, ubicada en el codón 88 de la proteína del síndrome de Wiskott-Aldrich (p. Y88X; c.264C > G), asociada a una variante clásica. Conclusiones: La identificación temprana, diagnóstico y estratificación del fenotipo, es esencial para reducir los eventos desfavorables y complicaciones de la afección. El estudio genético es el medio de confirmación diagnóstica definitivo para el síndrome, lo que permite aplicar el protocolo terapéutico más adecuado para este tipo de inmunodeficiencia.

ABSTRACT Introduction: Wiskott Aldrich syndrome is a primary immunodeficiency, rarely inherited in a recessive way and linked to the X chromosome. It is associated with variable clinical phenotypes that correlate with the type of mutation present in the Wiskott Aldrich syndrome protein. Objective: Examine the case of a patient diagnosed with Wiskott Aldrich and presence of a mutation not described above. Case presentation: Male patient whose symptoms began at three months of age, with recurrent respiratory infections, purpuric hemorrhagic lesions such as ecchymosis, eczema and platelettopenia. The diagnosis was confirmed one year of after the symptoms onset with the detection of a mutation not previously described, located in codon 88 of the Wiskott Aldrich syndrome protein (p. Y88X; c.264C>G), associated with a classical variant. Conclusions: Early identification, diagnosis and stratification of the phenotype is essential to reduce unfavorable events and complications of the condition. The genetic study is the mean of definitive diagnostic confirmation for the syndrome, which allows to apply the most appropriate therapeutic protocol for this type of immunodeficiency.

Expression and significance of Rac1 and WAVE2 in glomerulus of high-fat diet induced C57BL/6J model mice / 天津医药

Objective To explore the expression and significance of Rac1 and WAVE2 protein in glomerulus of high- fat diet induced C57BL/6J model mice. Methods Thirty-two male C57BL/6J mice (3-week old) were randomly assigned into two groups(16 in each group). The control group was fed with basic diet (10%fat) for 4 weeks. The high-fat diet group was fed with high-fat diet (60%fat) for 4 weeks. The kidney morphological changes were examined by HE and PAS staining. The expressions of Rac1 and WAVE2 protein were examined by Western blot and immunohistochemistry analysis. Results HE and PAS results showed that there were glomeruli mesangial matrix hyperplasia and exudation in high-fat diet group compared with control group. The immunohistochemistry and Western blotting results showed that expressions of Rac 1 and WAVE2 in glomerulus were both increased in high-fat diet group compared with those of control group. Conclusion Rac1 and WAVE2 protein may be involved in glomerular injuries induced by high-fat diet.

Effect of oxidative stress on human Wiskott-Aldrich syndrome related protein 2 expression in placental trophoblasts in preeclampsia / 中华围产医学杂志

Objective To explore the effect of oxidative stress on human Wiskott-Aldrich syndrome related protein 2 (WAVE2) expression in placental trophoblasts in women with preeclampsia.Methods (1) Twenty women with preeclampsia and twenty-three normal term pregnant women,delivered from August 15,2011 to February 23,2012 in the First Affiliated Hospital of Chongqing Medical University,were recruited and divided into preeclampsia group and control group.Placenta samples were collected after cesarean section.The localization and distribution of WAVE2 in placenta was studied by immunohistochemistry.Quantitative real-time polymerase chain reaction and Western blot were employed to assay the WAVE2 mRNA and protein levels.Tissue homogenates was applied to determine the levels of reactive oxygen species (ROS).The correlation between ROS levels and WAVE2 was also analyzed.(2) An in vitro hypoxia/reoxygenation (H/R) model was utilized to simulate ischemia/reperfusion injury to placental trophoblasts.The HTR-8/ SVneo cells (immortalized human first trimester extravillous trophoblast cells) were pre-incubated overnight,after exposure to H/R or normoxic conditions for 48 hours.Flow cytometry was employed to analyze intracellular ROS level.Meanwhile,Transwell assay was utilized to analyze the invasion and migration of HTR-8/SVneo cells.The location and expression of WAVE2 in trophoblasts was evaluated by cell immunofluorescence and Western blot.Statistical differences between the two groups were evaluated by independent t-tests.Pearson's correlation coefficient test was used for correlation analysis.Results (1)Compared with the control group,preeclampsia group had significantly higher 24-hour proteinuria [(1.96±0.24) g vs (0.08±0.05) g,t=19.436,P＜0.05],systolic blood pressure [(154 ± 13) mm Hg vs (98 ±11) mm Hg,t=11.324,P＜0.05] and diastolic blood pressure [(105±14) mm Hgvs (69±8) mm Hg,t=9.612,P＜0.05].In addition,the placental weight and birth weight of infants in preeclampsia group were significantly reduced as compared to the control group [(432±53) g vs (536±67) g,(2446± 187) g vs (3207± 233) g,t=14.562 and 16.307,allP＜0.05)].The WAVE2 mRNA level (0.28±0.07 vs 1.01±0.02,t=12.747,P＜0.05) and the WAVE2 protein levels (0.63±0.08 vs 1.34±0.19,t=11.648,P＜0.05) were also significantly decreased in preeclampsia groups.The level of ROS in placenta in the preeclampsia group was significantly higher than in control group [(144.22 ± 12.32) nmol/(mg · prot) vs (75.17 ± 8.71) nmol/(mg · prot),t=20.467,P＜0.05].There was significant negative correlation between ROS level and WAVE2 protein expression in preeclamptic placenta (r =-0.726,P =0.000).(2) In vitro study showed that,the levels of ROS in normoxia group and H/R group was (82.9±5.8)％ and (155.6±8.1)％,(t=12.747,P＜0.05).Compared with normoxia condition,decreased cell invasion and migration were found in HTR-8/SVneo cells in H/R group [(51.9 ± 3.3)％ and (58.4 ±4.2)％ respectively,t=11.034 and 13.839,P＜0.05].Results from the cell immunofluorescence showed that WAVE2 protein located in the cytoplasm of HTR-8/SVneo cells,and the expression of WAVE2 protein was significant decreased in HTR-8/SVneo cells after exposure to H/R for 48 h (0.37±0.05 vs 0.76±0.06,t=8.631,P＜0.05).Conclusions Excessive oxidative stress in preeclamptic placentas was correlated with the decreased expression of WAVE2.H/R-induced oxidative stress could decrease WAVE2 expression,which may contribute to impaired trophoblast invasion and migration in preeclampsia.

A Familial Case of Wiskott-Aldrich Syndrome with a Hotspot Mutation in Exon 2 of the WAS Gene

The Wiskott-Aldrich syndrome (WAS) is a severe X-linked disorder characterized classically by thrombocytopenia, immunodeficiency, and eczema. The phenotype observed in this syndrome is caused by mutation in the WAS gene. Peripheral blood DNAs were isolated from an 18-month-old boy with WAS and his mother, maternal uncle, and maternal grandmother. Genetic analysis for the detection of a mutation of WAS gene was performed by polymerase chain reaction-single strand conformational polymorphism analysis (PCR-SSCP) and direct sequencing of the PCR product. In PCR-SSCP, the patient and his maternal uncle had an abnormal shift band, which was not found in normal controls, and his mother and maternal grandmother showed heterozygous bands. In direct sequencing analysis, the patient with WAS had CGC-->CAC point mutation in exon 2 that resulted in an amino acid change in codon 86 (Arg86His). The present study identified a gene mutation responsible for WAS at a mutation hotspot of the WAS gene in a Korean family.