The role of allogeneic hematopoietic stem cell transplantation and Epstein‐Barr virus infection on the treatment for child primary hemophagocytic lymphohistiocytosis patients with X‐linked lymphoproliferative disease: A rare case report and family survey study

XLP‐2 is known as a rare primary immunodeficiency disease, which is characterized by the susceptibility to EBV infection and potential development into the pHLH. The existing studies believe that the dysfunction of XIAP represents one of the most significant pathogenic mechanisms of XLP‐2, and allo‐HSCT is regarded as a crucial treatment for the long‐term survival in XLP‐2 patients. In our present study, a 2‐year‐old male patient was diagnosed with XLP‐2. After receiving chemotherapy by using HLH‐2004 without allo‐HSCT, he reached a complete remission, and his EBV load was brought under control. Our family survey revealed a novel frameshift mutation in the XIAP gene in this patient, as well as in his cousin and grandfather. Until now, the patient has been followed up for 22 months with no recurrence reported yet. Based on these findings, it is believed that for child pHLH patients with XLP‐2, the treatment by controlling symptoms alone without allo‐HSCT and with regular monitoring of EBV load could be conducive to a long‐term survival.     

Lymphocytic vasculitis involving the central nervous system occurs in patients with X‐linked lymphoproliferative disease in the absence of Epstein–Barr virus infection

X‐linked lymphoproliferative disease (XLP) is an immunodeficiency caused by defects in the adaptor molecule SAP. The manifestations of XLP generally occur following Epstein–Barr virus (EBV) infection and include fulminant mononucleosis, hypogammaglobulinemia and lymphoma. In this report, we describe two unrelated patients with fatal T‐cell‐mediated central nervous system vasculitis for whom repeated serologic and molecular testing for EBV was negative. In both patients, clonal T‐cell populations were observed, but neither demonstrated evidence of lymphoma. Thus, loss of SAP function can lead to dysregulated immune responses characterized by the uncontrolled expansion and activation of T cells independent of EBV infection. Pediatr Blood Cancer 2009;53:1120–1123. © 2009 Wiley‐Liss, Inc.     

Haploidentical hematopoietic stem cell transplantation for a case with X‐linked chronic granulomatous disease

CGD is a rare primary immunodeficiency with high mortality rates when treated conventionally, especially for the X‐chromosome‐linked form. HSCT is the only curative therapy for CGD; however, haploidentical transplantation in CGD is rare. Here, we report a case of X‐linked CGD treated successfully by haploidentical HSCT. The patient showed a positive result with full donor chimerism, good quality of life, and the absence of recurrent infectious diseases at follow‐up (68 months). Thus, haploidentical HSCT may serve as an acceptable treatment approach for patients who have CGD, but no HLA‐matched related or unrelated donor.     

Fatal hemophagocytic lymphohistiocytosis in X‐linked chronic granulomatous disease associated with a perforin gene variant

A patient with previously unrecognized X‐linked chronic granulomatous disease (X‐CGD) died of multi‐organ failure, secondary to ongoing infection and hemophagocytic lymphohistiocytosis (HLH). Post mortem histological investigations were compatible with X‐CGD, and a CYBB gene mutation was confirmed. No homozygous mutations in the genes encoding perforin (PRF1), MUNC 13‐4 or syntaxin‐11 (STX11) were found; however, there was a heterozygous alteration c.1471G>A in the PRF1 gene causing a p.Asp491Asn substitution. Although this substitution has not been reported to cause primary or secondary HLH, we speculate that it may have made the patient more susceptible for HLH under the circumstances of ongoing infection associated with X‐CGD. Pediatr Blood Cancer 2009;52:527–529. © 2008 Wiley‐Liss, Inc.     

Potentially effective method for fetal gender determination by noninvasive prenatal testing for X‐linked disease

Examination of maternal plasma cell‐free DNA (cfDNA) for noninvasive prenatal testing for fetal trisomy is a highly effective method for pregnant women at high risk. This can be also applied to fetal gender determination in female carriers of severe X‐linked disease. Polymerase chain reaction (PCR) analysis is a relatively simpler and less expensive method of detecting Y chromosome‐specific repeats (Y‐specific PCR; YSP), but is limited by the risk of false‐negative results. To address this, we have developed a combined strategy incorporating YSP and an estimation of the fetal DNA fraction. Multiplex PCR for 30 single nucleotide polymorphism (SNP) loci selected by high heterozygosity enables the robust detection of the fetal DNA fraction in cfDNA. The cfDNA sample is first subjected to YSP. When the YSP result is positive, the fetus is male and invasive testing for an X‐linked mutation is then required. When the YSP result is negative, the cfDNA sample is analyzed using multiplex PCR. If fetal DNA is then found in the cfDNA, invasive testing is not then required. If the multiplex PCR analysis of cfDNA is negative for fetal DNA, the fetal gender cannot be determined and invasive testing is still required. Our technique provides a potentially effective procedure that can help to avoid unnecessary invasive prenatal testing in some female carriers of severe X‐linked disease.     

Post‐transplant EBV‐related lymphoproliferative disorder complicating umbilical cord blood transplantation in patients of adrenoleukodystrophy

EBV‐associated post‐transplant lymphoproliferative disorder (PTLD) is a well‐recognized complication following solid organ transplantation and hematopoietic stem cell transplantation (HSCT) using bone marrow or peripheral blood as stem cell sources, but rarely reported in umbilical cord blood transplantation (UCBT). We report two cases in unrelated UCBT setting and added the following new information to the literature: (i) EBV‐related PTLD can be presented late in recipients of unrelated UCBT; (ii) in contrast to reported literatures that PTLD is a serious complication with unfavorable outcome, especially in monomorphic form, our cases showed that the clinical course may be relatively benign if treatment is initiated promptly. Pediatr Blood Cancer 2009; 53:1329–1331. © 2009 Wiley‐Liss, Inc.     

Prenatal molecular diagnosis of X‐linked hydrocephalus via a silent C924T mutation in the L1CAM gene

We present a case of a patient whose L1CAM gene in X‐chromosome has a C924T transition. Her first son's ventriculomegaly was prenatally detected. A mature infant was born, his head circumference was large, and thumbs were bilaterally adducted. X‐linked hydrocephalus (XLH) was suspected. The DNA examination revealed that both her and boy's LICAM gene had a C924T transition. She became pregnant 5 years later and amniocentesis was performed. The results of cytogenetic analysis revealed that the fetus was female. She continued her pregnancy and delivered a healthy girl. She again became pregnant 3 years later. The chromosomal analysis revealed that the fetus was male. Fetal DNA analysis determined that the fetus had the inherited mutation. She chose to terminate the pregnancy. A C924T mutation can be disease causing for XLH, and the detection of this mutation would aid in genetic counseling for the prenatal diagnosis of XLH.     

Transitional cell carcinoma in a patient with X‐linked hyperimmunoglobulin M syndrome

Patients with X‐linked hyperimmunoglobulin M syndrome (XHIGM) have a defective CD40–CD40 ligand system and further immunoglobulin class‐switching. They may present with recurrent infection and malignancy involving the liver, pancreas or biliary tract. We report here a case of poorly differentiated transitional cell carcinoma in a young man with XHIGM even on regular treatment and discuss the possible pathogenesis. Given that the triggering of the CD40–CD40 ligand system has been found to improve tumor immunogenicity in recent studies, future immunotherapy targeting the CD40 ligand for these patients may be feasible to prolong their survival.     

Prompt diagnosis and management of Epstein–Barr virus‐associated post‐transplant lymphoproliferative disorder and hemophagocytosis: A dreaded complication in a post‐liver transplant child

EBV‐associated PTLD is increasingly recognized as an important cause of morbidity and mortality in both solid organ and hematopoietic stem cell transplant recipients. Mortality rates due to PTLD and virus‐induced HLH are reported to be quite high. We report a case of EBV‐associated PTLD and HLH in a child after liver transplantation who was successfully managed due to timely intervention. This case highlights that measurement of EBV load by quantitative polymerase chain reaction assays is an important aid in the surveillance and diagnosis of PTLD and early detection of EBV‐induced PTLD, and aggressive treatment with rituximab is a key to survival in patients who have undergone liver transplantation.