Breakthroughs in the understanding and therapy of primary immunodeficiency

The First Purine Nucleoside Phosphorylase Deficiency Patient Resembling IgA Deficiency and a Review of the Literature

Purine nucleoside phosphorylase (PNP) deficiency is a rare autosomal recessive primary immunodeficiency disorder characterized by decreased numbers of T-cells, variable B-cell abnormalities, decreased amount of serum uric acid and PNP enzyme activity. The affected patients usually present with recurrent infections, neurological dysfunction and autoimmune phenomena. In this study, whole-exome sequencing was used to detect mutation in the case suspected of having primary immunodeficiency. We found a homozygous mutation in PNP gene in a girl who is the third case from the national Iranian registry. She had combined immunodeficiency, autoimmune hemolytic anemia and a history of recurrent infections. She developed no neurological dysfunction. She died at the age of 11 after a severe chicken pox infection. PNP deficiency should be considered in late-onset children with recurrent infections, autoimmune disorders without typical neurologic impairment.

Lymphoma Secondary to Congenital and Acquired Immunodeficiency Syndromes at a Turkish Pediatric Oncology Center

The prevalence of lymphoma in primary immunodeficiency cases and autoimmune diseases, as well as on a background of immunodeficiency following organ transplants, is increasing. The lymphoma treatment success rate is known to be a low prognosis. Our study aimed to emphasize the low survival rates in immunodeficient vs. immunocompetent lymphoma patients and also to investigate the effect of rituximab in patients with ataxia telangiectasia and other immunodeficiencies. We summarized the clinical characteristics and treatment results of 17 cases with primary immunodeficiency that developed non-Hodgkin lymphoma (NHL) and Hodgkin lymphoma (HL) retrospectively. Seven patients were diagnosed with ataxia-telangiectasia, two with common variable immunodeficiency, two with selective IgA deficiency, one with X-related lymphoproliferative syndrome, one with Wiskott-Aldrich syndrome, one with Epstein-Barr virus-related lymphoproliferative syndrome, one with interleukin-2-inducible T-cell kinase (ITK) deficiency, and one with lymphoma developing after autoimmune lymphoproliferative syndrome (ALPS). One patient underwent a renal transplant. Of the nine males and eight females (aged 3-12 years, median = 7) that developed lymphoma, seven were diagnosed with HL and ten with NHL (seven B-cell, three T-cell). The NHL patients were started on the Berlin-Frankfurt-Münster, POG9317, LMB-96, or R-CHOP treatment protocols with reduced chemotherapy dosages. HL cases were started on the doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) and/or cyclophosphamide, vincristine, procarbazine, and prednisone (COPP) protocol, also with modified dosages. Importantly, all seven cases of HL are alive and in remission, while six of the ten NHL patients have died. Primary immunodeficiency is a strong predisposing factor for developing lymphoma. Low treatment success rates relative to other lymphomas and difficulties encountered during treatment indicate that new treatment agents are needed. While some success has been achieved by combining rituximab with lymphoma treatment protocols in B-NHL cases with primary immunodeficiency, the need for new treatment approaches for these patients remains critical.

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].

Chronic gingivitis in a new BTK mutation

A 5-yr-old Caucasian boy with a new mutation in Bruton's tyrosine kinase (BTK) is described. Full sequencing of the BTK gene revealed a point mutation in exon 17 resulting in an amino acid change from tryptophan to serine at location 581 of the tyrosine kinase domain. Clinically the child presented with chronic gingivitis and had no prior history of bacterial infections. Whereas serum immunoglobulin M (IgM) levels were undetectable, IgG levels were in the low normal range. The gingivitis completely resolved after intravenous immunoglobulin therapy. Lymphocyte phenotyping revealed 0.05% B cells in his peripheral blood, which were IgG(-), IgM(+), IgD(+), CD38(+), CD20(+), CD27(-). However, 40% of the B cells also expressed CD5. This subpopulation of B cells has not previously been described in X-linked agammaglobulinaemia (XLA) patients. We suggest that the occurrence of CD5(+) B cells could correlate with a late onset and mild clinical presentations of XLA.

Oral manifestations of primary immunological diseases

BACKGROUND

Primary immunodeficiencies have many oral manifestations. The clinical presentation of these diseases demonstrates the roles of different immune cells for the maintenance of oral health.

METHODS

The authors reviewed selected literature describing systemic and oral manifestations of the primary immunodeficiencies published between 1966 and 1999.

RESULTS

The authors found that oral candidiasis and herpetic infections are seen frequently in patients with T-cell deficiencies, while patients with B-cell deficiencies are most susceptible to bacterial infections. Periodontitis and oral candidiasis are found in some, but not all, phagocyte deficiencies.

CONCLUSIONS

These findings demonstrate that T cells, B cells and phagocytes all have roles in oral immunity.

CLINICAL IMPLICATIONS

Acquired conditions that affect the immune system such as diabetes, alcoholism and acquired immunodeficiency syndrome, as well as certain medications, will affect oral defense mechanisms. The effects that acquired immunodeficiencies will have on oral health can be predicted from the oral manifestations of primary immunodeficiencies.

Cutaneous markers of primary immunodeficiency diseases in children

Primary immunodeficiency diseases (PIDs) are rare but important conditions found predominantly in children. We studied PIDs in a large pediatric hospital, their association with cutaneous alterations, and the importance of cutaneous alterations as diagnostic markers. Among 382,383 pediatric patients, 130 (0.0003%) had a PID: humoral in 27, cellular and combined in 18, phagocytic in 37, and associated with major defects in 45. An average of two cutaneous alterations were present in 90 (69%) patients: infections in 80, eczema-dermatitis in 38, and miscellaneous in 57. In 71 (79%) patients the cutaneous alterations preceded and were the basis for the clinical immunologic diagnosis. Only two PIDs were not associated with cutaneous lesions.

Therapy for non-Hodgkin lymphoma in children with primary immunodeficiency: analysis of 19 patients from the BFM trials

BACKGROUND

Non-Hodgkin lymphomas (NHL) represent an important complication of primary immunodeficiency (ID), posing new therapeutic challenges in this patient population. This study analyzes clinical data and therapy results of pediatric patients with primary ID and NHL in three consecutive NHL-BFM trials.

PROCEDURE

Retrospective analysis of children with primary ID and NHL, treated according to protocol NHL-BFM, was performed regarding clinical presentation, diagnostic features, therapy, and outcome.

RESULTS

From October, 1986, to April, 1997, 19 of 1,413 newly diagnosed patients with NHL were registered as suffering from primary ID. Age at diagnosis of NHL was lower in patients with ID. Six patients suffered from humoral ID, 13 patients from combined ID (ataxia teleangiectasia n = 3; Nijmegen breakage syndrome n = 4; PNP deficiency n = 1; IL2 receptor defect n = 1, other combined ID n = 4). Thirteen lymphomas were of B-cell and six of T-cell-lineage. Four of thirteen patients with combined ID were diagnosed with T-NHL, nine with B-NHL. Two of six patients with humoral ID presented with T-NHL and four with B-NHL. NHL entities differed significantly between ID and non-ID patients (P < or = 0.01): centroblastic and immunoblastic lymphomas (31.6% vs. 8.1%), anaplastic large cell lymphoma (26.3% vs. 10.7%), Burkitt lymphoma and B-ALL (21% vs. 47. 8%). Seventeen patients received polychemotherapy. Therapy-related toxicity was increased in ID- compared to non-ID-patients. Three patients died of sepsis; three died of tumor progression; one patient relapsed; one died of BMT-related toxicity; one died of second malignancy. Ten patients are in first continuous remission after a median follow-up of 4 years.

CONCLUSIONS

Curative treatment of NHL in the presence of primary ID is possible and should be attempted.

Bone marrow transplantation for canine X-linked severe combined immunodeficiency

Canine X-linked severe combined immunodeficiency (XSCID) is due to mutations in the common gamma chain which is a subunit of the receptors of IL-2, IL-4, IL-7, IL-9 and IL-15. Bone marrow transplantation (BMT) of human XSCID patients without pretransplant conditioning (cytoablation) results in engraftment of donor T-cells and reconstitution of T-cell function but engraftment of few, if any, donor B cells with resultant poor reconstitution of humoral immune function. In this study, we show that XSCID dogs can be transplanted with allogeneic bone marrow cells resulting in engraftment of both donor B and T cells and reconstitution of full systemic immune function including normal humoral immune function without the need for cytoablation.

Full Immunologic Reconstitution Following Nonconditioned Bone Marrow Transplantation for Canine X-Linked Severe Combined Immunodeficiency

Bone marrow transplantation in human X-linked severe combined immunodeficiency (XSCID) without pretransplant conditioning results in engraftment of donor T cells and reconstitution of T-cell function but engraftment of few, if any, donor B cells and poor reconstitution of humoral immune function. Since bone marrow transplantation remains the most effective treatment of XSCID patients, better strategies are necessary to achieve optimum long-term results. Canine XSCID, like human XSCID, is due to mutations in the common γ chain (γc) gene and has clinical and immunologic features identical to those of human XSCID, making it a true homolog of the human disease. We have successfully performed bone marrow transplantation in three XSCID dogs without pretransplant conditioning, using untreated bone marrow cells from mixed lymphocyte culture–nonreactive normal littermates. Unlike the experience in human XSCID patients, all three dogs engrafted both donor B and T cells and attained full reconstitution of immunologic function. Normal percentages of T cells and T-cell mitogenic responses were attained by 3 months posttransplant. CD3+ T cells after transplantation expressed the CD45RA isoform indicating that the cells were recent thymic emigrants derived from immature progenitors. Serum IgG levels were within normal range by 5 months posttransplant. Immunization with the T-dependent antigen, bacteriophage φX174, demonstrated normal antibody titers, immunologic memory, and class-switching. Polymerase chain reaction (PCR) analysis of the γc locus showed that 100% of circulating T cells and 30% to 50% of circulating B cells were donor-derived. None of the dogs developed clinically evident graft-versus-host disease (GVHD). Thus, canine XSCID provides a model to determine the optimal conditions for bone marrow transplantation in human patients, and to develop and test strategies for somatic gene therapy.

Correction of purine nucleoside phosphorylase deficiency by transplantation of allogeneic bone marrow from a sibling

Deficiency of the purine salvage pathway enzyme purine nucleoside phosphorylase causes a combined immunodeficiency and neurologic abnormalities and is usually fatal in childhood. We report the first successful transplantation of bone marrow from a sibling with identical class II human leukocyte antigens in this condition, demonstrating correction of both lymphocyte metabolic and functional abnormalities.