Immunologic Heterogeneity in 2 Cartilage-Hair Hypoplasia Patients With a Distinct Clinical Course.

BACKGROUND AND OBJECTIVE: Cartilage-hair hypoplasia (CHH) syndrome is a rare autosomal recessive syndrome associated with skeletal dysplasia, varying degrees of combined immunodeficiency (CID), short stature, hair hypoplasia, macrocytic anemia, increased risk of malignancies, and Hirschsprung disease. To provide clinical and immunological insights obtained from 2 unrelated patients who displayed clinical characteristics of CHH. METHODS: Two patients with suspected CHH syndrome due to skeletal dysplasia and immunodeficiency underwent an immunological and genetic work-up using flow cytometry, next-generation sequencing (NGS) of the immune repertoire, and Sanger sequencing to identify the underlying defects. RESULTS: Patient 1 presented with low birth weight and skeletal dysplasia. Newborn screening was suggestive of T-cell immunodeficiency, as T-cell receptor excision circle levels were undetectable. Both the T-cell receptor (TCR) Vß and TCR-g (TRG) repertoires were restricted, with evidence of clonal expansion. Genetic analysis identified compound heterozygous RMRP variants inherited from both parents. Patient 2 presented with recurrent lung and gastrointestinal infections, skeletal dysplasia, failure to thrive, and hepatomegaly. The polyclonal pattern of the TCRß repertoire was normal, with only slight overexpression of TCR-ßV20 and restricted expression of Vßs. TRG expressed a normal diverse repertoire, similar to that of the healthy control sample. Genetic analysis identified biallelic novel regulatory variants in RMRP. Both parents are carriers of this mutation. CONCLUSION: Our findings demonstrate how the immunological work-up, supported by genetic findings, can dramatically change treatment and future outcome in patients with the same clinical syndrome.

Immunologic Heterogeneity in 2 Cartilage-Hair Hypoplasia Patients With a Distinct Clinical Course

Introduction: Cartilage-hair hypoplasia (CHH) syndrome is a rare autosomal recessive syndrome associated with skeletal dysplasia, varying degrees of combined immunodeficiency (CID), short stature, hair hypoplasia, macrocytic anemia, increased risk of malignancies, and Hirschsprung disease. Purpose: To provide clinical and immunological insights obtained from 2 unrelated patients who displayed clinical characteristics of CHH. Methods: Two patients with suspected CHH syndrome due to skeletal dysplasia and immunodeficiency underwent an immunological and genetic work-up using flow cytometry, next-generation sequencing (NGS) of the immune repertoire, and Sanger sequencing to identify the underlying defects. Results: Patient 1 presented with low birth weight and skeletal dysplasia. Newborn screening was suggestive of T-cell immunodeficiency, as T-cell receptor excision circle levels were undetectable. Both the T-cell receptor (TCR) Vß and TCR-g (TRG) repertoires were restricted, with evidence of clonal expansion. Genetic analysis identified compound heterozygous RMRP variants inherited from both parents. Patient 2 presented with recurrent lung and gastrointestinal infections, skeletal dysplasia, failure to thrive, and hepatomegaly. The polyclonal pattern of the TCRß repertoire was normal, with only slight overexpression of TCR-ßV20 and restricted expression of Vßs. TRG expressed a normal diverse repertoire, similar to that of the healthy control sample. Genetic analysis identified biallelic novel regulatory variants in RMRP. Both parents are carriers of this mutation. Conclusion: Our findings demonstrate how the immunological work-up, supported by genetic findings, can dramatically change treatment and future outcome in patients with the same clinical syndrome (AU)

Late diagnosis of chronic granulomatous disease.

Modern era advancements in medical care, with improved treatment of infections, can result in delayed diagnosis of congenital immunodeficiencies. In this study we present a retrospective cohort of 16 patients diagnosed with Chronic Granulomatous Disease (CGD) at adulthood. Some of the patients had a milder clinical phenotype, but others had a classic phenotype with severe infectious and inflammatory complications reflecting a profoundly impaired neutrophil function. It is therefore of great importance to investigate the individual journey of each patient through different misdiagnoses and the threads which led to the correct diagnosis. Currently the recommended definitive treatment for CGD is hematopoietic stem cell transplantation (HSCT). Although survival of our patients to adulthood might argue against the need for early HSCT during infancy, we claim that the opposite is correct, as most of them grew to be severely ill and diagnosed at a stage when HSCT is debatable with potentially an unfavorable outcome. This cohort stresses the need to increase awareness of this severe congenital immunodeficiency among clinicians of different specialties who might be treating undiagnosed adult patients with CGD.

Exogenous interleukin-2 can rescue in-vitro T cell activation and proliferation in patients with a novel capping protein regulator and myosin 1 linker 2 mutation.

Capping protein regulator and myosin 1 linker 2 (CARMIL2) deficiency is characterized by impaired T cell activation, which is attributed to defective CD28-mediated co-signaling. Herein, we aimed to analyze the effect of exogenous interleukin (IL)-2 on in-vitro T cell activation and proliferation in a family with CARMIL2 deficiency. This study included four children (one male and three females; aged 2·5-10 years at presentation). The patients presented with inflammatory bowel disease and recurrent viral infections. Genetic analysis revealed a novel homozygous 25-base pairs deletion in CARMIL2. Immunoblotting demonstrated the absence of CARMIL2 protein in all four patients and confirmed the diagnosis of CARMIL2 deficiency. T cells were activated in-vitro with the addition of IL-2 in different concentrations. CD25 and interferon (IFN)-γ levels were measured after 48 h and 5 days of activation. CD25 surface expression on activated CD8+ and CD4+ T cells was significantly diminished in all patients compared to healthy controls. Additionally, CD8+ T cells from all patients demonstrated significantly reduced IFN-γ production. When cells derived from CARMIL2-deficient patients were treated with IL-2, CD25 and IFN-γ production increased in a dose-dependent manner. T cell proliferation, as measured by Cell Trace Violet, was impaired in one patient and it was also rescued with IL-2. In conclusion, we found that IL-2 rescued T cell activation and proliferation in CARMIL2-deficient patients. Thus, IL-2 should be further studied as a potential therapeutic modality for these patients.

Altered T cell receptor beta repertoire patterns in pediatric ulcerative colitis.

The antigenic specificity of T cells occurs via generation and rearrangement of different gene segments producing a functional T cell receptor (TCR). High-throughput sequencing (HTS) allows in-depth assessment of TCR repertoire patterns. There are limited data concerning whether TCR repertoires are altered in inflammatory bowel disease. We hypothesized that pediatric ulcerative colitis (UC) patients possess unique TCR repertoires, resulting from clonotypical expansions in the gut. Paired blood and rectal samples were collected from nine newly diagnosed treatment-naive pediatric UC patients and four healthy controls. DNA was isolated to determine the TCR-ß repertoire by HTS. Significant clonal expansion was demonstrated in UC patients, with inverse correlation between clinical disease severity and repertoire diversity in the gut. Using different repertoire variables in rectal biopsies, a clear segregation was observed between patients with severe UC, those with mild-moderate disease and healthy controls. Moreover, the overlap between autologous blood-rectal samples in UC patients was significantly higher compared with overlap among controls. Finally, we identified several clonotypes that were shared in either all or the majority of UC patients in the colon. Clonal expansion of TCR-ß-expressing T cells among UC patients correlates with disease severity and highlights their involvement in mediating intestinal inflammation.

T and B cell clonal expansion in Ras-associated lymphoproliferative disease (RALD) as revealed by next-generation sequencing.

Ras-associated lymphoproliferative disease (RALD) is an autoimmune lymphoproliferative syndrome (ALPS)-like disease caused by mutations in Kirsten rat sarcoma viral oncogene homologue (KRAS) or neuroblastoma RAS viral (V-Ras) oncogene homologue (NRAS). The immunological phenotype and pathogenesis of RALD have yet to be studied extensively. Here we report a thorough immunological investigation of a RALD patient with a somatic KRAS mutation. Patient lymphocytes were analysed for phenotype, immunoglobulin levels and T cell proliferation capacity. T and B cell receptor excision circles (TREC and KREC, respectively), markers of naive T and B cell production, were measured serially for 3 years. T and B cell receptor repertoires were studied using both traditional assays as well as next-generation sequencing (NGS). TREC and KREC declined dramatically with time, as did T cell receptor diversity. NGS analysis demonstrated T and B clonal expansions and marked restriction of T and B cell receptor repertoires compared to healthy controls. Our results demonstrate, at least for our reported RALD patient, how peripheral T and B clonal expansions reciprocally limit lymphocyte production and restrict the lymphocyte receptor repertoire in this disease. Decreased naive lymphocyte production correlated with a clinical deterioration in our patient's immune status, suggesting that TREC and KREC may be used as an aid in monitoring disease progression. Both the methodologies used here and the conclusions regarding immune homeostasis may be applicable to the research of ALPS and other immune dysregulation syndromes.

Co-existence of clonal expanded autologous and transplacental-acquired maternal T cells in recombination activating gene-deficient severe combined immunodeficiency.

It is commonly accepted that the presence of high amounts of maternal T cells excludes Omenn syndrome (OS) in severe combined immunodeficiency (SCID). We report a SCID patient with a novel mutation in the recombination activating gene (RAG)1 gene (4-BP DEL.1406 TTGC) who presented with immunodeficiency and OS. Several assays, including representatives of specific T cell receptors (TCR), Vß families and TCR-γ rearrangements, were performed in order to understand more clearly the nature and origin of the patient's T cells. The patient had oligoclonal T cells which, based on the patient-mother human leucocyte antigen (HLA)-B50 mismatch, were either autologous or of maternal origin. These cell populations were different in their numbers of regulatory T cells (T(reg)) and the diversity of TCR repertoires. This is the first description of the co-existence of large amounts of clonal expanded autologous and transplacental-acquired maternal T cells in RAG1-deficient SCID.

Selective clinical and immune response of the oligoclonal autoreactive T cells in Omenn patients after cyclosporin A treatment.

The immunological hallmark of Omenn syndrome (OS) is the expansion and activation of an oligoclonal population of autoreactive T cells. These cells should be controlled rapidly by immunosuppressive agents, such as cyclosporin A (CsA), to avoid tissue infiltration and to improve the general outcome of the patients. Here we studied the clinical and the immune response to CsA in two Omenn patients and also examined the gene expression profile associated with good clinical response to such therapy. T cell receptor diversity was studied in cells obtained from OS patients during CsA therapy. Characterization of gene expression in these cells was carried out by using the TaqMan low-density array. One patient showed complete resolution of his symptoms after CsA therapy. The other patient showed selective response of his oligoclonal T cell population and combination therapy was required to control his symptoms. Transcriptional profile associated with good clinical response to CsA therapy revealed significant changes in 26·6% of the tested genes when compared with the transcriptional profile of the cells before treatment. Different clinical response to CsA in two OS patients is correlated with their immunological response. Varying clonal expansions in OS patients can cause autoimmune features and can respond differently to immunosuppressive therapy; therefore, additional treatment is sometimes indicated. CsA for OS patients causes regulation of genes that are involved closely with self-tolerance and autoimmunity.

Specific self-antigen-driven immune response in pericardial effusion as an isolated GVHD manifestation.

Pericardial effusion and cardiac tamponade have been described as GVHD manifestations in the post transplant period. Direct evidence of GVHD-related TCR or B-cell receptor clones in patients with pericardial effusion has never been described. Using several methods, including FACS and spectratyping analysis to assess T- and B-cell clonality and to quantify TCR excision circles to assess newly thymus-derived T cells, we were able to show expansion of oligoclonal T-cell populations and the possible presence of early/premature B cells in the pericardial effusion but not in peripheral mononuclear cells. This may explain the presentation of an isolated GVHD manifestation.

MHC class 2 deficiency and X-linked agammaglobulinaemia in a consanguineous extended family.

Manifestations of immunodeficiency within the same family are presumed to be the same disease. We report a consanguineous extended family where four patients have immunodeficiency, three have X-linked agammaglobulinaemia and one has major histocompatibility complex class 2 deficiency. Within one family, two rare genetic diseases with similar clinical manifestations can occur.

Matched unrelated bone marrow transplant for T+ combined immunodeficiency.

Little information is currently available on the outcome and the long-term restoration of immune function in infants with combined immunodeficiency and residual T cells (T+ CID) treated by BMT. We prospectively followed patients with T+ CID who received matched unrelated donor BMT at our center. Engraftment, immune reconstitution and transplant-related complications were recorded. Humoral and cellular immunity were evaluated. Ten patients with combined immune deficiency who had more than 1,000 circulating T cells/mul were designated as having T+ CID. They were diagnosed at a mean age of 9.7 months and received a matched unrelated donor BMT at the mean age of 17.4 months. All 10 patients are alive and well at a mean of 110 months after transplant. All patients have evidence of full hemopoietic engraftment and robust immune function. We have shown here that matched unrelated donor BMT is highly effective in curing patients with T+ CID. This mode of treatment should be preferred for patients with T+ CID when a related identical donor is not available.

Bone marrow transplantation for cartilage-hair-hypoplasia.

The association of cartilage hair hypoplasia (CHH) with severe combined immunodeficiency (SCID) has been known for more than three decades. Bone marrow transplantation (BMT) remains the only effective treatment that might cure SCID. Surprisingly little has been reported on the experience with BMT in CHH. We report here survival and long-term reconstitution of immunity after BMT in three patients with CHH. Regardless of whether a related human leukocyte antigen-matched or unrelated matched donors were used as the source of BMT, all patients are alive and well 5-20 years after BMT. Engraftment appears robust with most cells of donors origin. Repeated evaluation of the immune system showed normal cellular and humoral immunity. Our results should encourage the use of BMT in patients with CHH who have profound immunodeficiency.

Decreased immune response to hepatitis B eight years after routine vaccination in Israel.

BACKGROUND AND AIM: Although immunization of infants against hepatitis B virus (HBV) is the most effective way to prevent infection, duration of the afforded protection is unknown. Titers of anti-HBV antibodies decline with time, especially during the first few years after vaccination. Anti-HBV antibody levels were measured in the serum of vaccinated children in order to determine the duration of the response afforded by the primary course of HBV vaccine. METHODS: The immunity derived from the HBV vaccine was assessed by measuring antibody levels in 122 healthy children who were vaccinated in a routine vaccination program in Israel. RESULTS: Ninety-four children (77.1%) had detectable antibodies levels (HBsAb titer > or = 10 mIU/ml): 59 (48.4%) of the children had high antibodies levels (HBsAb titer > 100 mIU/ml). Twenty-eight children (22.9%) had undetectable antibodies levels (HBsAb titer < 10 mIU/ml). When the children were divided into three groups according to the time elapsed since vaccination, it was found that the antibody levels declined with time (p < 0.009). Most of the children with undetectable antibody levels belonged to the 5 to 8-y post-vaccination group (36.1% vs 20% and 14.6% for the 2.5 to 5-y and 1 to 2.5-y groups, respectively, p < 0.01). The mean HBsAb declined in relation to the length of time post-vaccination (226.9 +/- 248.2 mIU/ml for 1-2.5 y post-vaccination, 199.0 +/- 235.7 mIU/ml for 2.5-5 y and 90.4 +/- 138.5 for 5-8 y, p < 0.05). No correlation was found between HBsAb titers and gestational age, birthweight and parental origin, although females generated higher mean antibody levels than males (207.3 +/- 217 mIU/ml vs 141.9 +/- 218.9 mIU/ml, p < 0.05). CONCLUSION: Our data demonstrate a steady decline in anti-HBV titers over time after routine vaccination against HBV in Israel. The most significant decline occurred 5-8 y post-vaccination.

Vitamin D deficiency and insufficiency in Orthodox and non-Orthodox Jewish mothers in Israel.

BACKGROUND: The modest clothing that Orthodox Jewish women wear exposes very little of their skin to sunlight. Under these conditions they may develop vitamin D deficiency, even in sunny Israel. OBJECTIVES: To determine and compare the vitamin D nutritional status in Jewish orthodox mothers to that of non-orthodox mothers who live in the same metropolitan area in Israel. METHODS: 25-Hydroxyvitamin D was measured by competitive protein-binding radioassay in the sera of 341 Jewish Israeli mothers (156 orthodox and 185 non-orthodox). The sera were obtained 48-72 hours after childbirth during the late summer of 1998 and the spring of 1999. RESULTS: The mean (SD) serum concentration of 25-OHD was significantly (P < 0.002) lower (13.5 +/- 7.5 ng/ml) in the orthodox than in the non-orthodox mothers (18.6 +/- 9.6 ng/ml). Vitamin D deficiency (< 5 ng/ml) and insufficiency (< 10 ng/ml) were more common in the orthodox mothers (5.1% and 32.7% respectively) than in the non-orthodox mothers (2.7% and 13%, respectively). In subgroups of mothers supplemented with 400 units of vitamin D daily during pregnancy, vitamin D deficiency and insufficiency were less common (2.2% and 13%, respectively) in orthodox and non-orthodox mothers (0% and 8.1%, respectively). Vitamin D insufficiency was more common in the winter than in the summer only among non-orthodox mothers. CONCLUSIONS: The high prevalence of vitamin D deficiency and insufficiency in Israeli mothers raises the question whether vitamin D supplements should be given to pregnant women in Israel, at least to orthodox mothers.

Procalcitonin correlates with C-reactive protein as an acute-phase reactant in pediatric patients.

BACKGROUND: Previous reports on the behavior of procalcitonin blood levels in diverse clinical conditions suggest that it is part of the activation of cellular immunity and is another acute-phase reactant. OBJECTIVE: To compare procalcitonin with C-reactive protein, a well-known acute-phase reactant, in a series of acutely febrile pediatric patients and to review recent literature on procalcitonin. METHODS: Procalcitonin and CRP levels were evaluated in 38 blood samples of pediatric patients who were admitted to the Dana Children's Hospital for evaluation of unexplained fever or for sepsis work-up. RESULTS: The parallelism between procalcitonin and CRP was found to be highly significant (P < 0.01). CONCLUSION: The rise of procalcitonin blood levels in febrile pediatric patients suggests that it is part of the acute-phase reaction, parallel with the CRP reaction.