Apresentação atípica de síndrome de hiper-IgM ligada ao X simulando doença inflamatória intestinal / Atypical presentation of X-linked hyper-IgM syndrome simulating inflammatory bowel disease

Relatamos o caso de um paciente do sexo masculino, que iniciou quadro de úlceras em trato gastrointestinal, associado a febre recorrente e diarreia com muco e sangue aos 10 meses de vida, suspeitado inicialmente de doença inflamatória intestinal, no entanto, não apresentou melhora do quadro com terapia imunossupressora, sendo realizada investigação para erro inato da imunidade. Nos exames laboratoriais, apresentou níveis baixos de IgG e IgA e níveis elevados de IgM e neutropenia persistente. Diante disso, foi realizado teste genético que confirmou diagnóstico de síndrome de hiper-IgM ligada ao X. Os erros inatos da imunidade podem se manifestar com doenças do trato gastrointestinal, de forma relativamente frequente, devendo entrar como diagnóstico diferencial de diarreia crônica. Inclusa nesse grupo de doenças, as síndromes de hiper-IgM constituem um grupo heterogêneo de doenças, possuindo em comum níveis significativamente baixos ou ausentes de IgG e IgA e níveis normais ou elevados de IgM, o que predispõe a infecções e febre recorrente; além de outras alterações laboratoriais, como neutropenia, que pode estar associada a úlceras no trato gastrointestinal e proctite, simulando apresentação clínica de doença inflamatória intestinal. Para o paciente relatado, foi iniciada terapia com imunoglobulinas de forma periódica, além de antibioticoprofilaxia para infecções, evoluindo com resposta clínica satisfatória. O artigo possui objetivo principal de alertar para o diagnóstico diferencial de erros inatos da imunidade diante do quadro apresentado, visando o diagnóstico precoce e a instituição da terapia adequada.

We report the case of a male patient, who started with ulcers in the gastrointestinal tract, associated with recurrent fever and diarrhea with mucus and blood at 10 months of life, initially suspected of inflammatory bowel disease, however, he did not improve the condition with immunosuppressive therapy, being investigated for inborn error of immunity. In laboratory tests, he had low levels of IgG and IgA and high levels of IgM and persistent neutropenia. Therefore, a genetic test was performed and confirmed the diagnosis of X-linked hyper IgM syndrome. Inborn errors of immunity can manifest relatively frequently with diseases of the gastrointestinal tract, and should be included as a differential diagnosis of chronic diarrhea. Included in this group of diseases, hyper-IgM syndromes constitute a heterogeneous group of diseases, having in common significantly low or absent levels of IgG and IgA and normal or high levels of IgM, which predispose to infections and recurrent fever; in addition to other laboratory alterations, such as neutropenia, which may be associated with ulcers in the gastrointestinal tract and proctitis, simulating the clinical presentation of inflammatory bowel disease. For the reported patient, therapy with immunoglobulins was started periodically, in addition to antibiotic prophylaxis for infections, evolving with a satisfactory clinical response. The main objective of the article is to alert to the differential diagnosis of inborn errors of immunity in view of the presented condition, aiming at early diagnosis and the institution of adequate therapy.

Genetic analysis of a child with co-commitment progressive multifocal leukoencephalopathy and X-linked hyper IgM syndrome / 中华医学遗传学杂志

OBJECTIVE@#To detect variant of the CD40L gene and infection of Jamestown Canyon virus (JCV) in a 7-year-and-9-month-old boy with co-commitment progressive multifocal leukoencephalopathy (PML) and X-linked hyper IgM syndrome (XHIGM).@*METHODS@#Peripheral blood samples of the child and his parents were collected for the extraction of genomic DNA. The 5 exons and exon/intronic boundaries of the CD40L gene were subjected to PCR amplification and sequencing. Suspected variants were analyzed by using bioinformatic software. The JCV gene was amplified from genomic DNA by nested PCR and sequenced.@*RESULTS@#The child was found to harbor a hemizygous c.506 A>C (p.Y169S) missense variant in exon 5 of the CD40L gene. The variant may affect the TNFH domain of the CD40L protein and result in structural instability and loss of hydrophobic interaction between CD40L and CD40. As predicted by PolyPhen2 and SIFT software, the variant was probably damaging (score = 1.00) and deleterious (score= -8.868). His mother was found to be a heterozygous carrier, while the same variant was not found in his father. Gel electrophoresis of the nested PCR product revealed presence of target JCV band, which was confirmed to be 99% identical with the JCV gene by sequencing.@*CONCLUSION@#The patient was diagnosed with co-commitment XHIGM and PML based on the testing of the CD40L gene and JCV infection.

Primer trasplante de progenitores hematopoyéticos en un paciente con inmunodeficiencia primaria en Uruguay: síndrome de hiper IgM ligafo al X / First hematopoietic stem cell transplantation in a patient with primary inmunodeficiency in Uruguay: X-linked hyper IgM syndrome

Introducción: el trasplante alogénico de progenitores hematopoyéticos (TPH) es el único tratamiento de las inmunodeficiencias congénitas severas con potencial curativo. El síndrome hiper-IgM ligado al X tipo 1 (HIGM-1) -causado por mutaciones en el gen que codifica el ligando CD40- es una inmunodeficiencia primaria (IDP) con alta morbimortalidad a pesar de tratamientos de soporte adecuados, debido a infecciones recurrentes y colangiopatía. Describimos el primer TPH en una IDP en nuestro país en un niño con HIGM-1 con enfermedad hepática ya establecida. Métodos: un paciente con HIGM-1 con infecciones reiteradas, falla de crecimiento, y colangiopatía documentada por biopsia hepática fue sometido a TPH alogénico de su hermana HLA idéntica. El condicionamiento fue no mieloablativo con fludarabina, melfalan y globulina antitimocítica. Resultados: el niño lleva dos años del TPH. El quimerismo es 100% del donante. Está libre de infecciones, independiente de inmunoglobulina intravenosa y su colangiopatía impresiona resuelta. Los estudios de laboratorio confirman la corrección del defecto inmunológico. Conclusión: el TPH alogénico de donante HLA idéntico realizado con condicionamiento no mieloablativo permitió la reconstitución inmune en un niño con HIGM-1 y colangiopatía preexistente, sin toxicidad hepática severa.

Characterization of B Cells of Lymph Nodes and Peripheral Blood in a Patient with Hyper IgM Syndrome

PURPOSE: Hyper IgM syndrome(HIGM) is characterized by severe recurrent bacterial infections with decreased serum levels of IgG, IgA, and IgE but elevated IgM levels. Recently, it has been classified into three groups; HIGM1, HIGM2 and a rare form of HIGM. HIGM1 is a X-linked form of HIGM and has now been identified as a T-cell deficiency in which mutations occur in the gene that encodes the CD40 ligand molecule. HIGM2 is an autosomal recessive form of HIGM. Molecular studies have shown that the mutation of HIGM2 is in the gene that encodes activation-induced cytidine deaminase(AID). Recently, another rare form of X-linked HIGM syndrome associated with hypohydrotic ectodermal dysplasia has been identified. We encountered a patient with a varient form of HIGM2. To clarify the cause of this form of HIGM, we evaluated the peripheral B cells of this patient. METHODS: The lymphocytes of the patient were prepared from peripheral blood. B cells were immortalized with the infection of EBV. Cell cycle analysis was done with the immortalized B cells of the patient. Peripheral mononuclear cells were stained with monoclonal anti-CD40L antibody. Total RNA was extracted from the peripheral mononuclear cells. After RT-PCR, direct sequencing for CD40L gene and HuAID gene were done. Immunostainings of a lymph node for CD3, CD23, CD40, Fas-L, bcl-2, BAX were done. RESULTS: The peripheral B cells of this patient showed normal expression of CD40L molecule and normal sequencing of CD40L gene, and also normal sequencing of AID gene. Interestingly, the peripheral B cells of this patient showed a decreased population of G2/mitosis phase in cell cycles which recovered to normal with the stimulation of IL-4. CONCLUSION: We suspect that the cause of increased serum IgM in this patient may be from a decrease of G2/mitosis phase of the peripheral B cells, which may be from the decreased production or secretion of IL-4. Therefore, this may be a new form of HIGM.