Treatment of Omenn syndrome by bone marrow transplantation

Tailored treatments in inborn errors of immunity associated with atopy (IEIs-A) with skin involvement

Inborn errors of immunity associated with atopy (IEIs-A) are a group of inherited monogenic disorders that occur with immune dysregulation and frequent skin involvement. Several pathways are involved in the pathogenesis of these conditions, including immune system defects, alterations of skin barrier and metabolism perturbations. Current technological improvements and the higher accessibility to genetic testing, recently allowed the identification of novel molecular pathways involved in IEIs-A, also informing on potential tailored therapeutic strategies. Compared to other systemic therapy for skin diseases, biologics have the less toxic and the best tolerated profile in the setting of immune dysregulation. Here, we review IEIs-A with skin involvement focusing on the tailored therapeutic approach according to their pathogenetic mechanism.

Topical Hypochlorite and Skin Acidification Improves Erythroderma of Omenn Syndrome

We describe a case of Omenn syndrome displaying exudative erythroderma and other characteristic features, including alopecia, absent B and naïve T cells, hyper immunoglobulin E levels, and eosinophilia. A pathogenic recombination-activating RAG1 homozygous genetic mutation confirmed the diagnosis. She required frequent antibiotics at both treatment and prophylactic doses, which alone did not control her erythroderma, but her high risk of infection precluded the use of systemic agents such as cyclosporine, which would further suppress her already severely compromised immune system. Thrice-weekly topical dilute hypochlorite compresses, combined with skin acidification with a low pH emollient, were initiated to control inflammation and for cutaneous bacterial prophylaxis. She demonstrated a marked improvement in her erythroderma within days after treatment initiation. Further improvement continued with the addition of systemic corticosteroids, with resolution of erythroderma after her first dose. This case reveals for the first time that dilute topical hypochlorite and skin pH restoration holds promise to control severe dermatitis associated with immunodeficiency and inflammatory syndromes with minimal side effects.

Primary Immunodeficiency Masquerading as Allergic Disease

Primary immune deficiencies (PIDs) are an uncommon heterogeneous group of diseases that result from fundamental defects in the proteins and cells that enable specific immune responses. Common allergic reactions (eczema, allergic rhinitis, asthma, and food allergies) are exaggerated immune responses that may be manifestations of an underlying PID. Early diagnosis and treatment has significant bearing on outcome. Immune suppression with systemic corticosteroids in these immune compromised individuals can lead to life threatening dissemination of infections.

Cyclosporin treatment improves skin findings in omenn syndrome

Omenn syndrome is a combined immunodeficiency characterized by a generalized erythematous skin rash, enlarged lymph nodes, hepatosplenomegaly, severe susceptibility to infections, eosinophilia, and hyperimmunoglobulinemia E. A 3-month-old girl was admitted to our hospital with a history of recurrent sepsis. Physical examination revealed severe erythroderma, hepatosplenomegaly, lymphadenopathy, and failure to thrive. Laboratory findings revealed leukocytosis, lymphocytosis with high CD3 T-cells, a high CD4:CD8 ratio, absence of CD19 B-cells, high eosinophil count, and low immunoglobulin levels. A heterozygote RAG1 gene mutation was found. She had itchy, scaling, ichthyosiform erythroderma and protracted diarrhea. Cyclosporin treatment up to 10 mg/kg effectively resolved erythroderma and lowered total eosinophil counts, and she gained weight during treatment. Since extensive erythroderma with generalized itching causes patient discomfort in Omenn syndrome, cyclosporin treatment can be considered while waiting for treatment with hematopoietic stem cell transplantation.

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.

Successful second bone marrow transplantation in Omenn's syndrome after bone marrow aplasia: a case report

Omenn's syndrome is a rare inherited variant of SCID. It is inevitably fatal, unless treated by bone marrow or stem cell transplantation. However, treatment-related complications and graft rejection are major obstacles to the success of transplantation. In this report, we describe an eight-month-old baby with Omenn's syndrome and disseminated BCGosis, who underwent allogenic BMT from his HLA-matched sister using anti-GVHD prophylaxis but without a conditioning regimen. Ten days after BMT, he developed acute GVHD involving the skin only (grade 1) with a flare of local BCGosis. Engraftment of 55% was demonstrated by FISH as early as the 11th day post-BMT. On day +48 post-BMT, he developed GVHD that was complicated by refractory pancytopenia, resistant to three doses of rituximab. Patient was re-transplanted (from the same donor) after receiving fludarabine and ATG, with successful engraftment and complete recovery from pancytopenia.

Diagnosis and treatment of primary immunodeficiency disease in patients with gastrointestinal symptoms

An estimated 250,000 individuals in the Unites States have been diagnosed with a primary immunodeficiency disease (PIDD). Early diagnosis and treatment of PIDD are critical to minimizing morbidity and improving quality of life. Patients with certain subtypes of PIDD may present with gastrointestinal complaints such as chronic or acute diarrhea, malabsorption, gastrointestinal pain, and inflammatory bowel diseases. Therefore, gastroenterologists are well positioned to help identify patients with PIDD. The hallmarks of PIDD include recurrent or persistent infections, infections due to microorganisms that rarely cause significant disease in immunocompetent people, unusually severe or life-threatening infections, and either low or persistently high white blood cell counts. An assessment for PIDD involves detailed patient and family histories, a physical examination, and diagnostic screening tests. Immunoglobulin replacement therapy is the cornerstone of treatment for most subtypes of PIDD.

Transplantation of hematopoietic stem cells and long-term survival for primary immunodeficiencies in Europe: entering a new century, do we do better?

BACKGROUND

Hematopoietic stem cell transplantation remains the only treatment for most patients with severe combined immunodeficiencies (SCIDs) or other primary immunodeficiencies (non-SCID PIDs).

OBJECTIVE

To analyze the long-term outcome of patients with SCID and non-SCID PID from European centers treated between 1968 and 2005.

METHODS

The product-limit method estimated cumulative survival; the log-rank test compared survival between groups. A Cox proportional-hazard model evaluated the impact of independent predictors on patient survival.

RESULTS

In patients with SCID, survival with genoidentical donors (n = 25) from 2000 to 2005 was 90%. Survival using a mismatched relative (n = 96) has improved (66%), similar to that using an unrelated donor (n = 46; 69%; P = .005). Transplantation after year 1995, a younger age, B(+) phenotype, genoidentical and phenoidentical donors, absence of respiratory impairment, or viral infection before transplantation were associated with better prognosis on multivariate analysis. For non-SCID PID, in contrast with patients with SCID, we confirm that, in the 2000 to 2005 period, using an unrelated donor (n = 124) gave a 3-year survival rate similar to a genoidentical donor (n = 73), 79% for both. Survival was 76% in phenoidentical transplants (n = 23) and worse in mismatched related donor transplants (n = 47; 46%; P = .016).

CONCLUSION

This is the largest cohort study of such patients with the longest follow-up. Specific issues arise for different patient groups. Patients with B-SCID have worse survival than other patients with SCID, despite improvements in each group. For non-SCID PID, survival is worse than SCID, although more conditions are now treated. Individual disease categories now need to be analyzed so that disease-specific prognosis may be better understood and the best treatments planned.

Bone marrow transplantation for primary immunodeficiency diseases

Advances in immunology have led to a breathtaking expansion of recognized primary immunodeficiency diseases (PID) with over 120 disease-related genes identified. In North America alone more than 1000 children have received allogeneic blood or marrow transplant over the past 30 years, with the majority surviving long term. This review presents results and highlights challenges and notable advances, including novel less toxic conditioning regimens, to transplant the more common and severe forms of PID. HLA-matched sibling donors remain the ideal option, however, advances in living donor unrelated HSCT and banked umbilical cord blood grafts provide hope for all children with severe PID.

Rapid full engraftment and successful immune reconstitution after allogeneic hematopoietic stem cell transplantation with reduced intensity conditioning in Omenn syndrome

OS is a variant of SCID characterized by generalized erythroderma, alopecia, eosinophilia, and elevated IgE levels. It is fatal unless treated with allogeneic HSCT, which is the only curative approach. However, treatment related complications and graft rejection are major obstacles to the success of treatment. In this report, we describe a patient with OS, complicated by prolonged cytomegalovirus infection, successfully treated by reduced intensity conditioning allogeneic HSCT from sibling donor.

Omenn's syndrome: lessons from a red baby

Exfoliative dermatitis and erythroderma in infancy are rare. Clinicians need to be alert to the possible diagnosis of Omenn's syndrome (OS), a rare form of combined immunodeficiency in infants presenting with exfoliative dermatitis, erythroderma, recurrent infections, eosinophilia and raised IgE. OS is fatal unless treated by bone-marrow transplantation (BMT). We describe a 3-week-old girl who presented with a widespread scaly erythematous rash and stomatitis, and was initially treated for presumed atopic eczema and primary herpes stomatitis. Aged 3 months, she developed erythroderma, diarrhoea and hepatosplenomegaly associated with eosinophilia, raised serum IgE and low IgG, IgA and IgM levels, abnormal lymphocyte populations and skin histology, consistent with a diagnosis of OS. She remains well 16 months after a human leucocyte antigen-matched bone-marrow transplant from an unrelated donor.

Primary Immunodeficiencies

Primary immunodeficiencies (PIDs), once considered to be very rare, are now increasingly recognized because of growing knowledge in the immunological field and the availability of more sophisticated diagnostic techniques and therapeutic modalities [161]. However in a database of >120,000 inpatients of a general hospital for conditions suggestive of ID 59 patients were tested, and an undiagnosed PID was found in 17 (29%) of the subjects tested [107]. The publication of the first case of agammaglobulinemia by Bruton in 1952 [60] demonstrated that the PID diagnosis is first done in the laboratory. However, PIDs require specialized immunological centers for diagnosis and management [33]. A large body of epidemiological evidence supports the hypothesis of the existence of a close etiopathogenetic relation between PID and atopy [73]. In particular, an elevated frequency of asthma, food allergy (FA), atopic dermatitis and enteric pathologies can be found in various PIDs. In addition we will discuss another subject that is certainly of interest: the pseudo-immunodepressed child with recurrent respiratory infections (RRIs), an event that often requires medical intervention and that very often leads to the suspicion that it involves antibody deficiencies [149].

Omenn syndrome: a lack of tolerance on the background of deficient lymphocyte development and maturation

PURPOSE OF REVIEW

Omenn syndrome is a rare inherited primary immunodeficiency characterized by severe combined immunodeficiency in combination with autoimmune features leading to squamous erythrodermia, alopecia, lymphadenopathy, hepatosplenomegaly, and intractable diarrhea. Recent advances include characterizing the genetic basis of the syndrome and integrating the genetic defects into knowledge of tolerance induction.

RECENT FINDINGS

Molecular studies have shown that besides the well-known hypomorphic recombination activating gene defects, mutations in the nonhomologous end-joining factor Artemis and in the interleukin-7 receptor alpha chain can contribute to the development of Omenn syndrome. These investigations established that Omenn syndrome is a genetically heterogeneous condition. Whereas the majority of patients with Omenn syndrome bear hypomorphic gene alterations, some exhibit somatic mosaicism due to second-site reversions of null alleles. A lack of central tolerance contributes to the autoimmune pathology of the disease.

SUMMARY

Research has begun to clarify the genetic defects and the conditions underlying the lack of tolerance enforcement that predispose to Omenn syndrome. Clinical applications of this research include the identification of the causative genetic defect in the majority of Omenn syndrome cases and the use of this genetic knowledge in family and prenatal analyses and in difficult differential autoimmune diagnoses.

Novel adopted immunotherapy for mixed chimerism after unrelated cord blood transplantation in Omenn syndrome

Omenn syndrome is a variant form of severe combined immunodeficiency. It is fatal unless treated by allogeneic stem cell transplantation (SCT), which is the only curative approach. However, both treatment-related complications and graft rejection are major obstacles to treatment success. This report describes a case with Omenn syndrome who developed mixed chimerism after unrelated cord blood transplantation (UCBT). This case was successfully treated by altering the patient's immunosuppression and donor lymphocyte infusion (DLI) with donor cord blood-derived activated CD4+ T cells ex vivo expanded from the cord blood cell residues in an infused bag. This novel development to expand CD4+ T-lymphocytes from the donor cord blood unit for the use of DLI would serve as a useful method to overcome the risk of graft rejection in SCT for primary immunodeficiency disorders with residual cell-mediated immunity without compounding graft-vs.-host disease, especially in the UCBT setting.

Hematopoietic stem cell transplantation in Omenn syndrome: a single-center experience

We retrospectively analyzed the outcome of hematopoietic stem cell transplantations (HSCT) performed at our Center between 1991 and 2002 in 11 unselected patients with Omenn syndrome, a variant of severe combined immunodeficiency. The patients' mean age at the time of the first HSCT was 8.4 months. Two patients received two, and one patient three, HSCT procedures. The resulting 15 HSCT derived in seven cases from HLA-haploidentical parents, in four patients from matched unrelated donors, in three cases from an HLA phenotypically identical related donor, and in one case from an HLA genotypically identical family donor. Nine out of 11 patients are alive and immunoreconstituted 30-146 months after transplantation. At the time of the most recent evaluation, all of the nine survivors had normal T-cell function, and eight of them had developed normal antibody production. This study demonstrates an overall mortality of 18.2%, which is substantially lower than previously reported. Early recognition of OS, rapid initiation of adequate supportive treatment and HSCT lead to improved outcome for this otherwise fatal disease, regardless of the origin and matching of hematopoietic stem cells.

CAMPATH-1M T-cell depleted BMT for SCID: long-term follow-up of 19 children treated 1987-98 in a single center

BACKGROUND

SCID can be cured by BMT. Depletion of mature T cells from BM has enabled HLA non-identical stem-cell transplantation. We report the outcome of 30 patients treated with 37 T-cell depleted BMT procedures using CAMPATH-1M in vitro between 1987-98 in a single center.

METHODS

Immune reconstitution and quality-of-life were assessed in 19 longterm survivors. All but two received pre-transplant conditioning. T- and B-cell chimerism, numbers and function were analyzed during a median follow-up of 5.3 years (range 1.33-12).

RESULTS

The overall engraftment rate was 59%, six children required repeated BMT and the survival rate was 63%. All have donor T cells, 58% normal T-cell numbers and 74% normal T-cell function. Of 17 evaluated, 16 patients (94%) have normal IgM and IgG levels, and production of specific Abs to protein Ags, but only 5/16 (31%) have a good response to pneumococcal polysaccharide. Early and late post-BMT complications were rare and there were no delayed deaths. Only one child continues on long-term i.v. Ig 4-years post-BMT. Eleven children died (37%).

DISCUSSION

CAMPATH-1M T-cell depleted BMT for SCID resulted in 63% survival. Deaths of 11 children were mainly due to pre-existing infections. Seventeen of 19 long-term survivors have normal immune function and good quality-of-life.

Mutations in conserved regions of the predicted RAG2 kelch repeats block initiation of V(D)J recombination and result in primary immunodeficiencies

The V(D)J recombination reaction is composed of multiple nucleolytic processing steps mediated by the recombination-activating proteins RAG1 and RAG2. Sequence analysis has suggested that RAG2 contains six kelch repeat motifs that are predicted to form a six-bladed beta-propeller structure, with the second beta-strand of each repeat demonstrating marked conservation both within and between kelch repeat-containing proteins. Here we demonstrate that mutations G95R and DeltaI273 within the predicted second beta-strand of repeats 2 and 5 of RAG2 lead to immunodeficiency in patients P1 and P2. Green fluorescent protein fusions with the mutant proteins reveal appropriate localization to the nucleus. However, both mutations reduce the capacity of RAG2 to interact with RAG1 and block recombination signal cleavage, therefore implicating a defect in the early steps of the recombination reaction as the basis of the clinical phenotype. The present experiments, performed with an extensive panel of site-directed mutations within each of the six kelch motifs, further support the critical role of both hydrophobic and glycine-rich regions within the second beta-strand for RAG1-RAG2 interaction and recombination signal recognition and cleavage. In contrast, multiple mutations within the variable-loop regions of the kelch repeats had either mild or no effects on RAG1-RAG2 interaction and hence on the ability to mediate recombination. In all, the data demonstrate a critical role of the RAG2 kelch repeats for V(D)J recombination and highlight the importance of the conserved elements of the kelch motif.

Acquired hypothyroidism in a very young infant with Omenn's syndrome

A very young male infant with Omenn's syndrome had acquired hypothyroidism that was most likely caused by autoimmune thyroiditis. The hypothyroidism appeared at 3 months of age. These 2 rare conditions have not previously been reported occurring together. This case suggests that autoimmune thyroiditis may be another abnormal finding in Omenn's syndrome.

Intrathymic Restriction and Peripheral Expansion of the T-Cell Repertoire in Omenn Syndrome

Mutations in the human RAG genes that impair, but do not abolish, recombination activity lead to Omenn syndrome, a severe primary immune deficiency that is associated with clinical and pathological features of graft-versus-host disease and oligoclonal expansion of activated, autologous T cells. We have analyzed the mechanisms accounting for peripheral oligoclonality of the T-cell repertoire. Predominance of few T-cell receptor clonotypes (both within TCRAB- and within TCRGD-expressing lymphocytes) is already detectable in the thymus and is further selected for in the periphery, with a different distribution of clonotypes in different tissues. These data indicate that oligoclonality of the T-cell repertoire in Omenn syndrome is due both to intrathymic restriction and to peripheral expansion. Moreover, the RAG genes defect that causes Omenn syndrome directly affects early stages of V(D)J recombination, but does not alter the process of double-strand-break DNA repair, including N and P nucleotide insertion.

RAG and RAG defects

Products of the recombination-activating gene (RAG) play a crucial role in lymphoid cell development. During the past year, the functional properties of RAG protein domains have been better defined. Some mutations that alter the amino acid sequence of RAG1 or RAG2 have been shown to disturb B cell generation and to partially disturb T cell generation, resulting in Omenn syndrome in humans; moreover, peripheral re-expression of RAGs indicates their role in lymphoid cell homeostasis.

Successful unrelated umbilical cord blood transplantation in a child with Omenn's syndrome

Omenn's syndrome is a variant of combined immunodeficiency disease (CID). Like other CID forms, it causes death unless the patient receives a bone marrow transplant (BMT). Previous reports have shown that BMTs from unrelated donors in Omenn's syndrome have very poor results, with a high rate of infections during transplantation and graft rejection, when compared with transplants from related donors or patients with other CID. This study discusses the case of a 19-month-old child with Omenn's syndrome, who received an unrelated cord blood stem cell transplant (CBT). Donor and recipient had 1 HLA-Ag mismatched on HLA-B. Symptomatology improved early after CBT. The child achieved leukocytes and platelet engraftment and was discharged on day +34. His follow-up has been uneventful and at this time, 27 months after CBT, immune functions have been recovered.

Omenn syndrome: a disorder of Rag1 and Rag2 genes

In vertebrates, generation of the T- and B-cell repertoire relies on genomic rearrangement of T-cell receptor and immunoglobulin gene coding segments. This process, known as V(D)J recombination, is initiated by the lymphoid specific proteins Rag1 and Rag2. Both in humans and in animal models, mutations that abrogate expression of either the Rag1 or Rag2 proteins result in severe combined immune deficiency with a complete lack of circulating T and B cells due to an early block in lymphoid development. We have recently shown that mutations that impair, but do not completely abolish the function of Rag1 and Rag2 in humans result in Omenn syndrome, an enigmatic form of combined immune deficiency characterized by oligoclonal, activated T lymphocytes with a skewed Th2 profile.

Partial V(D)J recombination activity leads to Omenn syndrome

Genomic rearrangement of the antigen receptor loci is initiated by the two lymphoid-specific proteins Rag-1 and Rag-2. Null mutations in either of the two proteins abrogate initiation of V(D)J recombination and cause severe combined immunodeficiency with complete absence of mature B and T lymphocytes. We report here that patients with Omenn syndrome, a severe immunodeficiency characterized by the presence of activated, anergic, oligoclonal T cells, hypereosinophilia, and high IgE levels, bear missense mutations in either the Rag-1 or Rag-2 genes that result in partial activity of the two proteins. Two of the amino acid substitutions map within the Rag-1 homeodomain and decrease DNA binding activity, while three others lower the efficiency of Rag-1/Rag-2 interaction. These findings provide evidence to indicate that the immunodeficiency manifested in patients with Omenn syndrome arises from mutations that decrease the efficiency of V(D)J recombination.

In vitro cell death of activated lymphocytes in Omenn's syndrome

Omenn's syndrome (OS) is characterized by erythrodermia, hepatosplenomegaly, lymphadenopathy, hypereosinophilia and elevated IgE levels associated with increased susceptibility to severe infections. Peripheral blood T cells, though usually present in normal number, show an activated phenotype (including an increased expression of CD95/Fas), a Th2 pattern of cytokine secretion and defective proliferative response to mitogens. In this report, we demonstrate that T cells from patients with OS undergo an excessive cell death in vitro resulting from two mechanisms. First, a substantial number of peripheral blood lymphocytes from OS patients die in unstimulated cultures (p = 0.009 vs. healthy controls). This spontaneous apoptosis is associated with reduced expression of bcl-2 gene product (p < 0.05) and can be prevented by addition of interleukin (IL)-2 (which also prevents down-modulation of bcl-2), while is independent from CD95 signaling. Second, lymphocytes from OS patients are highly susceptible to activation-induced cell death (AICD) induced with mitogens. This mechanism is largely independent from IL-2, while it can be significantly inhibited blocking CD95 with an IgG2b monoclonal antibody (mAb). The dependence of AICD from signals transduced via CD95 was confirmed showing that cross-linking CD95 with an IgM mAb induces a higher cell death in purified CD4+ CD45R0+ cells from OS patients than in controls (comparable for CD95 expression). Both mechanisms of cell death observed in this study result from lymphocyte hyperactivation occurring in vivo in these patients and may contribute to functional T cell defects of OS.

Parental consent for bone marrow transplantation in the case of genetic disorders

PURPOSE

To describe the responses of mothers and fathers who were offered bone marrow transplantation (BMT) for their children with genetic disorders.

DESIGN

Qualitative.

SETTING

Private hospital rooms/offices.

PARTICIPANTS

Six mothers and 4 fathers of children with genetic disorders.

RESULTS

The basic social-psychological problem confronting the parents was the conflicting alternatives of life versus death for their children. It was certain that these children would die from their genetic disorders but without having to endure the pain and suffering of a BMT. The BMT would be difficult, possibly resulting in death, but with a chance of survival.

CONCLUSIONS

Parents believed that BMT was the only chance of survival for their children, leaving them no choice except to pursue the BMT treatment.