Three-year cardiovascular and non-cardiovascular adverse events in patients with chronic lymphocytic leukemia or small cell lymphocytic lymphoma treated with Bruton tyrosine kinase inhibitors acalabrutinib or ibrutinib: a real-world analysis.

Bruton tyrosine kinase (BTK) inhibitors play an important role in targeted treatment of B-cell lymphoproliferative disorders. However, adverse events may limit the proper course of treatment in many patients. The purpose of this study is to compare the risk of cardiovascular and non-cardiovascular adverse events in patients with chronic lymphocytic leukemia (CLL) or small cell lymphocytic lymphoma (SLL) treated with the first-generation BTK inhibitor ibrutinib versus second-generation acalabrutinib, using real-world data from a collaborative multinational network. We used data from the network (TriNetX), which encompasses more than 100 healthcare organizations worldwide. We queried the database for patients aged ≥ 18 years with chronic lymphocytic leukemia or small-cell lymphomas treated with ibrutinib or acalabrutinib in the past ten years before the analysis. We used propensity score matching to balance the cohorts. The 3-year cumulative incidences and hazard ratios for the following outcomes were calculated: atrial flutter or fibrillation, other arrhythmias, heart failure, ischemic stroke or peripheral embolism, acute coronary syndrome, bleeding, and sepsis. We compared 2,107 patients in each group. Atrial fibrillation or flutter occurred in 150 (7.1%) patients with acalabrutinib and 310 (14.7%) patients with ibrutinib during the 3-year follow-up (hazard ratio, 0.68, 95% CI 0.55-0.84). New-onset hypertension occurred in 342 (16.3%) patients in the acalabrutinib group and 584 (27.7%) patients in the ibrutinib group (hazard ratio 0.81, 95% CI 0.66-0.98). Sepsis was diagnosed in 136 (6.5%) patients in the acalabrutinib group versus 239 (11.3%) patients in the ibrutinib group (hazard ratio 0.77, 95 CI 0.60-0.98). The two groups had no significant differences concerning the other adverse events. In a large retrospective cohort using real-world data from electronic medical registers, patients with CLL or SLL treated with acalabrutinib had a better cardiovascular and non-cardiovascular safety profile than those treated with ibrutinib, with lower risks of atrial flutter or fibrillation, new-onset arterial hypertension, and sepsis.

Bruton's tyrosine kinase inhibitors in primary central nervous system lymphoma: New hopes on the horizon.

In this editorial, we comment on the article by Wang et al. This manuscript explores the potential synergistic effects of combining zanubrutinib, a novel oral inhibitor of Bruton's tyrosine kinase, with high-dose methotrexate (HD-MTX) as a therapeutic intervention for primary central nervous system lymphoma (PCNSL). The study involves a retrospective analysis of 19 PCNSL patients, highlighting clinicopathological characteristics, treatment outcomes, and genomic biomarkers. The results indicate the combination's good tolerance and strong antitumor activity, with an 84.2% overall response rate. The authors emphasize the potential of zanubrutinib to modulate key genomic features of PCNSL, particularly mutations in myeloid differentiation primary response 88 and cluster of differentiation 79B. Furthermore, the study investigates the role of circulating tumor DNA in cerebrospinal fluid for disease surveillance and treatment response monitoring. In essence, the study provides valuable insights into the potential of combining zanubrutinib with HD-MTX as a frontline therapeutic regimen for PCNSL. The findings underscore the importance of exploring alternative treatment modalities and monitoring genomic and liquid biopsy markers to optimize patient outcomes. While the findings suggest promise, the study's limitations should be considered, and further research is needed to establish the clinical relevance of this therapeutic approach for PCNSL.

First report of Wilson disease and Bruton agammaglobulinemia in the same patient caused by new mutations in ATP7B and BTK genes.

INTRODUCTION: Wilson disease is characterized by an alteration in copper metabolism that causes its accumulation in different tissues. Its diagnosis is established by the combination of clinical manifestations and paraclinical and genetic studies. Bruton agammaglobulinemia is an X-linked recessive hereditary disease belonging to the group of primary immunodeficiencies and is produced by mutation in the Bruton tyrosine kinase (BTK) gene. CASE REPORT: A 14-year-old Colombian patient with clinical characteristics of Bruton agammaglobulinemia presented with liver disease and clinically and molecularly diagnosed with Wilson disease. DISCUSSION: Bruton agammaglobulinemia and Wilson disease are considered rare diseases because of their low prevalence. We report for the first time a pediatric patient from southwestern Colombia presenting with both entities, and diagnosed clinically and molecularly, an association so far not reported in the literature.

Current Perspectives: Evidence to Date on BTK Inhibitors in the Management of Multiple Sclerosis.

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system leading to demyelination and neurodegeneration. Basic and translational studies have shown that B cells and myeloid cells are critical players for the development and course of the disease. Bruton's tyrosine kinase (BTK) is essential for B cell receptor-mediated B cell activation and for normal B cell development and maturation. In addition to its role in B cells, BTK is also involved in several functions of myeloid cells. Although significant number of disease-modifying treatments (DMTs) have been approved for clinical use in MS patients, novel targeted therapies should be studied in refractory patients and patients with progressive forms of the disease. On the basis of its role in B cells and myeloid cells, BTK inhibitors can provide attractive therapeutic benefits for MS. In this article, we review the main effects of BTK inhibitors on different cell types involved in the pathogenesis of MS and summarise recent advances in the development of BTK inhibitors as novel therapeutic approaches in different MS clinical trials. Available data regarding the efficacy and safety of these drugs are described.

Linfoma de Burkitt como complicación de la agammaglobulinemia de Bruton / Burkitt's lymphoma as a complication of Bruton's Agammaglobulinemia

Introducción: La agammaglobulinemia de Bruton es una inmunodeficiencia primaria (IDP) originada por una mutación del gen que codifica la tirosina kinasa de Bruton (BTK). Se sospecha principalmente en varones con infecciones frecuentes de las vías respiratorias y tiene entre otras complicaciones, los tumores, fundamentalmente linfoproliferativos. Se reportan agammaglobulinemias autosómicas recesivas con similares características clínicas en ambos sexos. Objetivo: Presentar el primer caso pediátrico reportado en Cuba, con diagnóstico de linfoma de Burkitt asociado a esta inmunodeficiencia primaria y que además utilizó tratamiento combinado sustitutivo de inmunoglobulinas y antitumoral. Presentación del caso: Paciente masculino, que a los 2 años se le realizó diagnóstico de enfermedad de Bruton. Con el tratamiento de reemplazo con inmunoglobulina endovenosa (Intacglobín) se mantuvo tres años sin infecciones graves. A los 5 años de edad presentó linfoma de Burkitt, tratado con poliquimioterapia, según el esquema AEIOP al que se asoció rituximab. Aunque no se dispone de la detección por biología molecular de la mutación del gen BTK, la disminución por debajo del 2 por ciento de las células B CD19+ y los valores ausentes de IgG, IgA e IgM permitieron el diagnóstico. Conclusión: Coexistieron con resultados clínicos satisfactorios el tratamiento antitumoral y la terapia de reemplazo con inmunoglobulina endovenosa. El paciente se mantiene con buen estado general(AU)

Introduction: Bruton's Agammaglobulinemia is a primary immunodeficiency (PID) caused by a mutation in the gene that encodes Bruton's tyrosine kinase (BTK). It is suspected mainly in men with frequent respiratory tract infections and has, among other complications, tumors, mainly lymphoproliferative. Autosomal recessive agammaglobulinemias with similar clinical characteristics have been reported in both sexes. Objective: To present the first pediatric case reported in Cuba, with a diagnosis of Burkitt's lymphoma associated with PID and that also used combined immunoglobulin replacement and antitumor therapy. Case report: 2-year-old male diagnosed with Bruton's disease. With the replacement treatment with intravenous immunoglobulin (Intacglobin), he maintained three years without serious infections. At 5 years of age, he presented Burkitt's lymphoma, treated with polychemotherapy according to the AEIOP scheme, associating Rituximab. Although do not have molecular biology detection of the BTK gene mutation, the decrease of CD19 + B cells to below 2 percent and the absent values of IgG, IgA and IgM allowed the diagnosis. Conclusion: Antitumor treatment and intravenous immunoglobulin replacement therapy coexisted with satisfactory clinical results. The patient remains in good general condition(AU)

Emerging protein kinase inhibitors for the treatment of rheumatoid arthritis.

INTRODUCTION: Protein tyrosine kinase inhibitors are emergent drugs in the treatment of rheumatoid arthritis (RA); they block the signal transduction in immune cells preventing the production and release of pro-inflammatory cytokines. AREAS COVERED: The current research aims to review the role of Janus, Bruton's and spleen kinase inhibitors for the treatment of RA. Mechanism of action, rationale for usage, and the main efficacy and safety outcomes in phase II and III clinical trials are described. EXPERT OPINION: In RA, the development of Bruton kinase inhibitors was interrupted because they failed to demonstrate superiority versus placebo. The spleen kinase inhibitors had their development deprioritized because their risk/benefit profile was unfavorable compared to janus kinase inhibitors (JAKi). JAKi proved to be effective in treatment naïve patients and in those with previous failure to methotrexate and/or biological therapy. There still remain important points about JAKi that need more studies: the clinical importance of JAKi selectivity should be further evaluated in head-to-head trials and the safety profile of JAKi, mainly regarding the risk of malignancy and thromboembolic events, must be analyzed in long-term real-life studies.

Extracellular vesicles and their associated miRNAs as potential prognostic biomarkers in chronic lymphocytic leukemia.

PURPOSE OF REVIEW: Many prognostic and predictive biomarkers have been proposed for chronic lymphocytic leukaemia (CLL). Here, we aim to discuss the evidence showing a prognostic potential for extracellular vesicles (EV) and their associated microRNAs (miRNAs). RECENT FINDINGS: EV are produced by several cells in the body as a physiological event; however, there is evidence suggesting that an elevated EV concentration is present in the circulation of CLL patients. Moreover, some studies have associated EV concentration with advanced Rai stage and unmutated CLL while others have demonstrated its potential as an independent prognostic factor for TTFT and OS. Finally, some studies have shown that CLL EV shared some dysregulated microRNAs with CLL cells and plasma. On the other hand, it was found that CLL EV has a distinctive microRNA expression profile. Until now, EV-associated miR-155 is the most studied miRNA. Despite methodological diversity and limitations in study design, unanimity in CLL EV concentration behaviour and miRNA content has been found.

Diagnóstico genético de pacientes con agammaglobulinemia primaria atendidos en centros peruanos de tercer nivel / Genetic diagnosis of patients with primary agammaglobulinemia treated at third level peruvian centers

Las agammaglobulinemias primarias (AP) resultan de alteraciones específicas en las células B, lo cual, conduce a baja producción de anticuerpos. La sospecha diagnóstica se establece con el antecedente de infecciones a repetición, inmunoglobulinas bajas y la ausencia linfocitos B CD19+. El diagnóstico se confirma mediante el análisis genético y la detección de una mutación ligada en el cromosoma X o autosómico recesiva o dominante. En Perú, no hay literatura sobre AP ni reportes sobre el genotipo de los pacientes con sospecha de AP. Bajo este escenario, se realizó un estudio que describió el genotipo de pacientes con sospecha de AP. Se encontraron 20 pacientes con mutaciones en el gen BTK y una mutación autosómica recesiva IGHM. Se hallaron 13 mutaciones hereditarias y siete mutaciones de novo. Se concluye que las AP son, en su mayoría, mutaciones en el gen BTK que corresponden con AP ligadas al cromosoma X.

Primary agammaglobulinemia result from specific alterations in B cells, which lead to low antibody production. Diagnostic suspicion is established with a history of repeated infections, low immunoglobulins, and absence of CD19+ B lymphocytes. The diagnosis is confirmed by genetic analysis and the detection of a mutation linked to the X or autosomal recessive or dominant chromosome. In Peru, there is no literature on primary agammaglobulinemia and no reports on the genotype of patients with suspected primary agammaglobulinemia. Under this scenario, a study was performed to describe the genotype of patients with suspected primary agammaglobulinemia. Twenty (20) patients were found with mutations in the BTK gene and an autosomal recessive IGHM mutation. Thirteen (13) hereditary mutations and seven de novo mutations were found. It is concluded that the group of primary agammaglobulinemia are mostly mutations in the BTK gene, corresponding to X-linked agammaglobulinemia.

Delayed diagnosis in X-linked agammaglobulinemia and its relationship to the occurrence of mutations in BTK non-kinase domains.

BACKGROUND: X-linked agammaglobulinemia (XLA) is characterized by the absence of immunoglobulin and B cells. Patients suffer from recurrent bacterial infections from early childhood, and require lifelong immunoglobulin replacement therapy. Mutations in BTK (Bruton's Tyrosine Kinase) are associated with this phenotype. Some patients that present XLA do not show typical clinical symptoms, resulting in delayed diagnosis due to the lack of a severe phenotype. This study presents a report of five XLA patients from four different families and attempts to determine a relationship between delayed diagnosis and the occurrence of BTK mutations. METHODS: Samples from patients with antibody deficiency were analyzed to determine BTK expression, immunophenotyping and mutation analysis. Clinical and laboratory data was analyzed and presented for each patient. RESULTS: Most patients presented here showed atypical clinical and laboratory data for XLA, including normal IgM, IgG, or IgA levels. Most patients expressed detectable BTK protein. Sequencing of BTK showed that these patients harbored missense mutations in the pleckstrin homology and Src-homology-2 domains. When it was compared to public databases, BTK sequencing exhibited a new change, along with three other previously reported changes. CONCLUSIONS: Delayed diagnosis and atypical manifestations in XLA might be related to mutation type and BTK expression.

Expression of Bruton's tyrosine kinase in B-cell neoplasms evaluated by flow cytometry.

Bruton's tyrosine kinase (BTK) is a cytoplasmatic protein that is part of the B-cell antigen receptor signaling pathway. Our aim was to evaluate the expression of BTK in B-cell neoplasms and compare it to normal B-cell lymphocytes. After surface staining with CD19 and CD45, flow cytometry staining for intracellular BTK was performed in leukemic or mature B-cells from bone marrow or peripheral blood samples. No differences in BTK expression were identified between groups, or in comparison to control samples, there was no association between BTK expression and the clinical variables evaluated. BTK expression in B-cell neoplasms was similar to that of normal B-cell lymphocytes.

[Clinic of humoral primary immunodeficiencies in adults. Experience in a tertiary hospital]. / Clínica de inmunodeficiencias primarias en adultos. Experiencia en un hospital de tercer nivel.

BACKGROUND: Primary immunodeficiencies (PID) are characterized by alteration of the components of the immune system. Humoral deficiencies represent 50%. The most common are selective IgA deficiency, Bruton agammaglobulinemia, and common variable immunodeficiency (CVID). OBJECTIVE: To describe the epidemiological and clinical characteristics of adults with humoral PID, cared for in a Primary Humoral Immunodeficiencies Clinic. METHODS: A descriptive cross-sectional study that included a year of analysis, including 35 patients with humoral PID, 31 with CVID, and 4 with Bruton agammaglobulinemia. Data were analyzed with descriptive statistics. RESULTS: Of 35 patients studied, 31 had CVID (88.5%) and 4 (11.5%) Bruton agammaglobulinemia; 21 were men and 14 women. The age at onset of symptoms was 22.7 years, and the delay in diagnosis was 7.2 years. 11.4% of CVID patients died during the study; 4 had malignancies, 22.8% autoimmune diseases, and 48.5% gastrointestinal disorders. Patients with Bruton agammaglobulinemia presented no comorbidities. CONCLUSIONS: Unlike reports in the literature, in the study group, CVID was the most common cause of humoral PID, predominantly in men; the most common gastrointestinal disorder was intestinal functional disorder.

Antecedentes: Las inmunodeficiencias primarias (IDP) son trastornos de los componentes del sistema inmune. Las deficiencias humorales representan el 50%. Las más comunes son el déficit selectivo de IgA, agammaglobulinemia de Bruton y la inmunodeficiencia común variable (IDCV). Objetivo: Describir las características epidemiológicas y clínicas de adultos con IDP humorales, atendidos en una Clínica de Inmunodeficiencias Primarias Humorales. Métodos: Estudio descriptivo trasversal que abarcó un año de análisis, en el que se incluyeron 35 pacientes con IDP humoral. Los datos se analizaron con estadística descriptiva. Resultados: De 35 pacientes estudiados, 31 tuvieron IDCV (88.5%) y 4 (11.5%) agammaglobulinemia de Bruton; 21 fueron hombres y 14 mujeres. La edad al inicio de los síntomas fue de 22.7 años y el tiempo de retraso en el diagnóstico fue de 7.2 años; 11.4% de los pacientes con IDCV fallecieron durante el estudio; 4 padecieron neoplasias, 22.8% enfermedades autoinmunes y 48.5% alteraciones gastrointestinales. Los pacientes con agammaglobulinemia de Bruton no presentaron comorbilidades. Conclusiones: A diferencia de lo informado en la literatura, la IDCV fue la causa más común de IDP humoral en el grupo estudiado, con predominio en hombres; la alteración gastrointestinal más común fue el trastorno funcional intestinal.

[X-linked agammaglobulinemia in adults. Clinical evolution]. / Agammaglobulinemia ligada al cromosoma X en adultos. Evolución clínica.

X-linked agammaglobulinemia (XLA) is characterized by absent or severely reduced B cells, low or undetectable immunoglobulin levels and clinically by extracellular bacterial infections which mainly compromise the respiratory tract as well as recurrent diarrheas. The mainstay of treatment is gammaglobulin replacement therapy, which allows most patients to reach adulthood with high quality of life. We analyzed the clinical features of 14 patients over 18 years of age with XLA diagnosis that received treatment in our unit from the year 2003, the date the first patient was derived, until 2015. The average age at which patients were referred was 20.4 years old; age at the last consult was 25.5. The average follow-up time was 59.8 months. Previously to being diagnosed all patients had suffered infections, most frequently respiratory. After diagnosis all were started on intravenous gammaglobulin replacement treatment and in spite of infections being reduced in severity and frequency, there were cases of severe disease with long term sequelae. At the beginning of our follow-up 35.7% presented impaired respiratory function with only one case being severe. In no cases during this period did the respiratory function worsen, nor were there severe clinical complications. Three patients were switched to subcutaneous immunoglobulin treatment with good tolerance. The number of XLA cases is increasing, as most reach the second decade of life without serious complications and remain free of severe infectious disease and further impairment of their respiratory functions with the treatment.

Agammaglobulinemia ligada al cromosoma X en adultos: Evolucion clínica / X-linked agammaglobulinemia in adults. Clinical evolution

La agammaglobulinemia ligada al cromosoma X (XLA) se caracteriza por la ausencia o reducción significativa de linfocitos B, niveles bajos o indetectables de inmunoglobulinas y, clínicamente, por infecciones principalmente respiratorias por bacterias capsuladas extracelulares y diarrea recurrente. El tratamiento de reemplazo con gammaglobulina ha permitido a la mayor parte de los enfermos llegar a adultos con una buena calidad de vida. Analizamos las características clínicas de 14 pacientes mayores de 18 años con diagnóstico de XLA asistidos en nuestra Unidad desde 2003, fecha en que fue derivado el primer paciente, hasta 2015. La edad promedio en el momento de la derivación fue de 20.4 años, en el momento de la última consulta de 25.5. El tiempo promedio de seguimiento fue de 59.8 meses. Previo al diagnóstico todos habían presentado infecciones, las más frecuentes fueron las respiratorias. Posteriormente al diagnóstico todos iniciaron tratamiento de reemplazo con gammaglobulina endovenosa, y a pesar de que las infecciones disminuyeron en frecuencia y gravedad, en este período se presentaron enfermedades con secuelas graves. Al comenzar el seguimiento en nuestra Unidad, 35.7% presentaban deterioro de la función respiratoria, solo grave en un paciente. Durante el seguimiento ninguno presentó deterioro de la función respiratoria ni complicaciones clínicas importantes. Tres pasaron a gammaglobulina subcutánea con buena tolerancia. El número de adultos con XLA es cada vez mayor, la mayoría llegan a la segunda década de la vida sin complicaciones graves y bajo tratamiento se mantienen libres de enfermedades infecciosas graves y de progresión de sus secuelas pulmonares.

X-linked agammaglobulinemia (XLA) is characterized by absent or severely reduced B cells, low or undetectable immunoglobulin levels and clinically by extracellular bacterial infections which mainly compromise the respiratory tract as well as recurrent diarrheas. The mainstay of treatment is gammaglobulin replacement therapy, which allows most patients to reach adulthood with high quality of life. We analyzed the clinical features of 14 patients over 18 years of age with XLA diagnosis that received treatment in our unit from the year 2003, the date the first patient was derived, until 2015. The average age at which patients were referred was 20.4 years old; age at the last consult was 25.5. The average follow-up time was 59.8 months. Previously to being diagnosed all patients had suffered infections, most frequently respiratory. After diagnosis all were started on intravenous gammaglobulin replacement treatment and in spite of infections being reduced in severity and frequency, there were cases of severe disease with long term sequelae. At the beginning of our follow-up 35.7% presented impaired respiratory function with only one case being severe. In no cases during this period did the respiratory function worsen, nor were there severe clinical complications. Three patients were switched to subcutaneous immunoglobulin treatment with good tolerance. The number of XLA cases is increasing, as most reach the second decade of life without serious complications and remain free of severe infectious disease and further impairment of their respiratory functions with the treatment.

QSAR analysis of nicotinamidic compounds and design of potential Bruton's tyrosine kinase (Btk) inhibitors.

Bruton's tyrosine kinase (Btk) is an important enzyme in B-lymphocyte development and differentiation. Furthermore, Btk expression is considered essential for the proliferation and survival of these cells. Btk inhibition has become an attractive strategy for treating autoimmune diseases, B-cell leukemia, and lymphomas. With the objective of proposing new candidates for Btk inhibitors, we applied receptor-dependent four-dimensional quantitative structure-activity relationship (QSAR) methodology to a series of 96 nicotinamide analogs useful as Btk modulators. The QSAR models were developed using 71 compounds, the training set, and externally validated using 25 compounds, the test set. The conformations obtained by molecular dynamics simulation were overlapped in a virtual three-dimensional cubic box comprised of 2 and 5 Å cells, according to the six trial alignments. The models were generated by combining genetic function approximation and partial least squares regression technique. The analyses suggest that Model 1a yields the best results. The best equation shows [Formula: see text], r(2) = .743, RMSEC = .831, RMSECV = .879. Given the importance of the Tyr551, this residue could become a strategic target for the design of novel Btk inhibitors with improved potency. In addition, the good potency predicted for the proposed M2 compound indicates this compound as a potential Btk inhibitor candidate.

Agammaglobulinemia ligada al x o de bruton / X-linked agammaglobulinemia or bruton´s disease

La agammaglobulinemia ligada al X (ALX) o de Bruton es una inmunodeficiencia primaria que generalmente se manifiesta en los primeros meses de la vida, cuando disminuyen las concentraciones séricas de las inmunoglobulinas maternas. Se caracteriza por infecciones recurrentes y ausencia total o niveles muy bajos de inmunoglobulinas. Se reporta el caso de un niño de 5 años de edad con historia de procesos infecciosos severos recurrentes de comienzo a los 18 meses de nacido: shigellosis, infecciones respiratorias bacterianas, bronconeumonías, conjuntivitis, sinusitis, meningoencefalitis en tres ocasiones (dos de etiología viral y una de etiología bacteriana), otitis media supurativa crónica, giardiasis de evolución tórpida y lesiones sépticas en piel por pseudomona aeruginosa y estafilococo dorado. Durante el curso de los procesos infecciosos se diagnosticó una enfermedad autoinmune (psoriasis). El estudio inmunológico realizado mostró niveles extremadamente reducidos de las inmunoglobulinas séricas: IgG 0,00 mg/L (370 - 1 400 mg/L); IgA 0,08 g/L (50 - 230 mg/L); e IgM 0,07 g/L (30 - 170 mg/L), así como células B CD19+ en sangre periférica casi ausentes, con un valor de 0,12 por ciento (VN: 21 - 44 por ciento ). Se estableció el diagnóstico de agammaglobulinemia ligada al X o de Bruton. El paciente recibió tratamiento con inmunoglobulina humana por vía endovenosa con mejoría clínica evidente...

X-linked agammaglobulinemia (XLA) or Bruton disease is a primary immunodeficiency, which typically appears in the first months of life, when serum concentrations of maternal immunoglobulins decrease. It is characterized by recurrent infections and total absence or very low levels immunoglobulin. We report a 5-year-old boy with a history of recurrent severe infectious processes beginning at 18 months of age: shigellosis, bacterial respiratory infections, bronchopneumonia, conjunctivitis, sinusitis, meningoencephalitis three times (two of viral etiology and one of bacterial etiology), chronic suppurative otitis media, giardiasis with torpid evolution and septic skin lesions caused by Pseudomona aeruginosa and Staphylococcus aureus. During the course of infectious processes an autoimmune disease (psoriasis) was diagnosed. Immunological study showed extremely low levels of serum immunoglobulins: IgG 0.00 mg / L (370 - 1 400 mg / L), IgA 0.08 g / L (50 - 230 mg / L), and IgM 0, 07 g / L (30 - 170 mg / L) and CD19 + B cells in peripheral blood almost absent, with a value of 0.12 percent (VN: 21 - 44 percent). Diagnosis of X-linked agammaglobulinemia or Bruton disease was established. The patient was treated with intravenous human immunoglobulin with obvious clinical improvement...

Mutations of Bruton's tyrosine kinase gene in Brazilian patients with X-linked agammaglobulinemia

Mutations in Bruton's tyrosine kinase (BTK) gene are responsible for X-linked agammaglobulinemia (XLA), which is characterized by recurrent bacterial infections, profound hypogammaglobulinemia, and decreased numbers of mature B cells in peripheral blood. We evaluated 5 male Brazilian patients, ranging from 3 to 10 years of age, from unrelated families, whose diagnosis was based on recurrent infections, markedly reduced levels of IgM, IgG and IgA, and circulating B cell numbers <2 percent. BTK gene analysis was carried out using PCR-SSCP followed by sequencing. We detected three novel (Ala347fsX55, I355T, and Thr324fsX24) and two previously reported mutations (Q196X and E441X). Flow cytometry revealed a reduced expression of BTK protein in patients and a mosaic pattern of BTK expression was obtained from mothers, indicating that they were XLA carriers.