The primary immunodeficiencies

Trisomy 4 pter-q12 and monosomy of chromosome 13 pter-q12 in a male with deficiency of all blood lymphocyte populations

A six-year-old male presented with multiple congenital anomalies, mental retardation, developmental delay, and an increased frequency of upper and lower respiratory infections and deficiency of all blood lymphocyte populations. Chromosome analysis showed an unbalanced translocation involving chromosomes 4 and 13, leading to partial trisomy for 4pter-q12 and partial monosomy for 13pter-q13 [karyotype, 46,XY,+der(4)t(4;13)(q12;q12),-13)]. The mother is the carrier of a balanced translocation involving chromosomes 4 and 13. The translocation is known to be segregating for three generations in this family. The child was found to have deficiency of all blood lymphocyte populations, but other hemopoietic lineages appeared to be normal. In addition, his fresh T cells were principally CD45RA+, CD62L+, and deficient in the Fas receptor. This deficiency of all blood lymphocyte populations may be due to an overdose of a gene or genes located in the region of chromosome 4 or a partial deficiency of a gene or genes in the region of chromosome 13 that regulate the development of the lymphocyte lineage. Since the mother contributed two copies of chromosomal region 4pter-q12 and no copy of 13pter-q12, the deficiency of all blood lymphocyte populations in our patient may be the result of either uniparental disomy or imprinting. A maternal granduncle with dissimilar dysmorphic features was not lymphopenic but was neutropenic.

Immunologic compensation in a patient with a large IgH constant region deletion

BACKGROUND

Deficiencies of serum Ig of the IgG isotype typically predispose individuals to recurrent infections in some but not all cases. Patients with large deletions of the Ig heavy chain genes are free of recurrent and severe infections.

OBJECTIVE

We sought to determine a mechanism of immunologic compensation that would possibly explain the reason for this patient's paucity of infection despite lacking several classes of serum Ig.

METHODS

The patient is a 50-year-old white man. Serum Ig levels and specific antibody titers were measured by using various methods, including nephelometry, enzyme immunoassay, and radial immunodiffusion. The status of the Ig heavy chain genes was examined by means of Southern blotting of genomic DNA isolated from EBV-transformed B cells.

RESULTS

The patient's serum lacked detectable IgG1, IgG2, IgG4, and IgA1 levels. Southern blot analysis demonstrated a large heavy chain constant (C) region gene deletion that included Cgamma1, Calpha1, psiCgamma, Cgamma2, and Cgamma4. Antibody responses to capsular pneumococcal and hemophilus polysaccharide antigens were essentially absent. However, IgG3 antibodies against the protein antigen tetanus toxoid were present. Relatively high antibody titers were found against pneumococcal surface proteins as well.

CONCLUSION

We conclude that our patient's relative freedom from serious infection may be as a result of production of IgG3 antibodies to pneumococcal capsular proteins.

Coexpression of Normal and Mutated CD40 Ligand with Deletion of a Putative RNA Lariat Branchpoint Sequence in X-Linked Hyper-IgM Syndrome

We describe a novel CD40 ligand (CD40L) splicing mutation in a patient with X-linked hyper-IgM syndrome (X-HIM) associated with alternate splicing of exon 3, resulting in the expression of both full-length and exon-3-skipped CD40L mRNA. The mutation is an 8-bp deletion 25 bp upstream of the intron 2/exon 3 junction which overlaps a putative RNA branchpoint, suggesting that it may impair RNA lariat formation. The exon-3-skipped CD40L transcript encodes a truncated protein (CD40LDeltaE3) encompassing the cytoplasmic, transmembrane, and extracellular stalk domains, but lacking the CD40L receptor binding domain. CD40LDeltaE3 protein expression was readily detectable in transfected Cos cells by immunofluorescence. In cells cotransfected with CD40LDeltaE3 and wild-type CD40L, expression of CD40LDeltaE3 did not inhibit the expression of wild-type CD40L monomers, but strongly inhibited staining by the conformationally sensitive anti-CD40L mAb 5c8, suggesting that CD40LDeltaE3 acts in a dominant negative manner to inhibit the assembly of functional CD40L trimers. This mechanism may contribute to the pathophysiology of CD40L deficiency in X-HIM patients with leaky splice site mutations.

Preferential Th1 profile of T helper cell responses in X-linked (Bruton's) agammaglobulinemia

X-linked agammaglobulinemia (XLA) is a primary immunodeficiency of the B-cell compartment caused by a defective gene encoding for the tyrosine kinase (btk) essential for B cell differentiation. Affected males undergo recurrent pyogenic infections and deficient immunoglobulin production. Peripheral blood T cells from 6 XLA patients and 6 matched healthy controls were stimulated with either PHA or tetanus toxoid (TT) and T cell clones obtained were compared for their cytokine profile. In the series of PHA-induced or TT-specific CD4(+) T cell clones derived from XLA patients, the Th1 profile was predominant (63 and 65 %, respectively). Upon stimulation with TT, the proportion of activated T cells from XLA that expressed the IFN-gamma -associated LAG-3 activation molecule was higher than in control T cells (51 vs. 25 %), whereas the expression of the IL-4-associated CD30 molecule was lower (5 vs. 21 %). In a cohort of 31 XLA patients, plasma levels of soluble (s)LAG-3 and sCD30, chosen as indirect indicators of the Th1 / Th2 activity in vivo, were significantly higher and lower, respectively, than those measured in 31 healthy controls. Likewise, plasma levels of interferon-inducible protein 10 and of macrophage-derived chemokine in XLA patients were significantly higher and lower, respectively, than in healthy controls.

Pulmonary mucosa-associated lymphoid tissue lymphoma in a patient with common variable immunodeficiency syndrome

Common variable immunodeficiency syndrome (CVID) is a primary immunodeficiency typically presenting with recurrent sinopulmonary infections. Non-Hodgkin's lymphoma and other secondary cancers are typical late complications of CVID. We report on a patient suffering from CVID with a history of recurrent sinopulmonary infections, interstitial pulmonary changes and hepatic granulomas. Despite treatment with intravenous immunoglobulin followed by a reduction in the number of pulmonary infections, reticular and nodular lung changes progressed. Video-assisted thoracoscopic lung biopsy showed a low-grade B cell lymphoma of the mucosa-associated lymphoid tissue (MALT) of the bronchus without evidence of pulmonary infection. In conclusion, MALT lymphoma of the lung should be considered in the differential diagnosis of progressive lung disease in CVID.

Clonal CD8 infiltration of the skin in common variable immunodeficiency: a prelymphomatous stage?

Common variable immunodeficiency is a heterogeneous syndrome characterized by hypogammaglobulinemia and recurrent bacterial infections. Patients with this syndrome also have an increased incidence of autoimmune disease and malignancy, most notably lymphoproliferative disorders. The treatment for common variable immunodeficiency is supported by the use of intravenous infusion of immunoglobulins that allows for control of the disease and avoidance of recurrent opportunistic infections. This report describes a young patient having common variable immunodeficiency who presented with a clonal CD8(+) lymphocytic infiltration of the skin clinically manifesting as a widespread papulonodular eruption and resolving with intravenous immunoglobulin therapy. We speculate that such a unique cutaneous presentation may represent a prelymphomatous condition because of the development of an autonomous T-suppressor/cytotoxic cell clone, possibly also responsible for the impaired immunoglobulin production.

X-linked agammaglobulinaemia and squamous lung cancer

A 32yr-old nonsmoking male, diagnosed as having X-linked agamma-globulinemia, presented with fever, cough with purulent sputum, a very intense back pain and a mass of 10 centimetres in lower left lobe. Diagnostic evaluation revealed a squamous cell carcinoma with very aggressive metastases at L3. Malignancies are the second leading cause of death in children and adults with congenital immunodeficiency disorders, mostly non-Hodgkin lymphomas and gastric and colon adenocarcinomas, but this is the first report of lung cancer in a patient with X-linked agammaglobulinemia. Lung cancer incidence has been reported to be higher in patients with other diseases of the lung, however, there is no clear evidence of the role of bronchiectasis in developing lung cancer. It is possible that a longer survival for patients with X-LA recently diagnosed, and an association of chronic bronchial infection, could favour the development of pulmonary neoplasm.

Respiratory disorders in common variable immunodeficiency

Common variable immunodeficiency (CVID) is a heterogeneous immunodeficiency syndrome characterized by hypogammaglobulinemia, recurrent bacterial infections, and various immunologic abnormalities. The clinical presentation is generally that of recurrent pyogenic sinopulmonary infections. Our objectives were to study the prevalence of lung involvement and the response to intravenous immunoglobulin replacement therapy in 19 patients with CVID. Nineteen patients (12 men) with a mean age (SD) of 33.1 (17.1) years had a previous diagnosis of CVID and were treated with intravenous immunoglobulin replacement. All patients underwent complete pulmonary function tests and high-resolution computed tomography (HRCT) examination. Bronchiectasis was diagnosed in 11 (58%) patients and eight (42%) were multi-lobar bronchiectasis. Chronic airflow limitation (CAL) was present in 10 (53%) patients and a restrictive pattern was seen in one case. Eleven patients (58%) presented a decrease in single-breath carbon monoxide diffusing capacity of the lung (DL(CO)). Before intravenous immunoglobulin replacement therapy (INIRT), 84% of patients had suffered from at least one episode of pneumonia. Episodes of lower respiratory tract infection decreased significantly from 0.28 per patient and year before replacement therapy to 0.16 per patient and year after treatment. The mean duration of replacement therapy was 7.5 years. In conclusion lung involvement was frequent in patients with CVID. Long-term administration of intravenous gammaglobulin resulted in a substantial reduction of pneumonic episodes.

Wasp, the Drosophila Wiskott-Aldrich syndrome gene homologue, is required for cell fate decisions mediated by Notch signaling

Wiskott-Aldrich syndrome proteins, encoded by the Wiskott-Aldrich syndrome gene family, bridge signal transduction pathways and the microfilament-based cytoskeleton. Mutations in the Drosophila homologue, Wasp (Wsp), reveal an essential requirement for this gene in implementation of cell fate decisions during adult and embryonic sensory organ development. Phenotypic analysis of Wsp mutant animals demonstrates a bias towards neuronal differentiation, at the expense of other cell types, resulting from improper execution of the program of asymmetric cell divisions which underlie sensory organ development. Generation of two similar daughter cells after division of the sensory organ precursor cell constitutes a prominent defect in the Wsp sensory organ lineage. The asymmetric segregation of key elements such as Numb is unaffected during this division, despite the misassignment of cell fates. The requirement for Wsp extends to additional cell fate decisions in lineages of the embryonic central nervous system and mesoderm. The nature of the Wsp mutant phenotypes, coupled with genetic interaction studies, identifies an essential role for Wsp in lineage decisions mediated by the Notch signaling pathway.

Treatment of giardiasis

Giardia lamblia is both the most common intestinal parasite in the United States and a frequent cause of diarrheal illness throughout the world. In spite of its recognition as an important human pathogen, there have been relatively few agents used in therapy. This paper discusses each class of drugs used in treatment, along with their mechanism of action, in vitro and clinical efficacy, and side effects and contraindications. Recommendations are made for the preferred treatment in different clinical situations. The greatest clinical experience is with the nitroimidazole drugs, i.e., metronidazole, tinidazole, and ornidazole, which are highly effective. A 5- to 7-day course of metronidazole can be expected to cure over 90% of individuals, and a single dose of tinidazole or ornidazole will cure a similar number. Quinacrine, which is no longer produced in the United States, has excellent efficacy but may be poorly tolerated, especially in children. Furazolidone is an effective alternative but must be administered four times a day for 7 to 10 days. Paromomycin may be used during early pregnancy, because it is not systematically absorbed, but it is not always effective. Patients who have resistant infection can usually be cured by a prolonged course of treatment with a combination of a nitroimidazole with quinacrine.

Hipogamaglobulinemia como fator de risco para infecção por Cryptococcus neoformans: a propósito de dois casos

Dois pacientes HIV-soronegativos com doença criptocócica refratária à terapia antifúngica convencional foram submetidos a estudo do sistema imune. Hipogamaglobulinemia foi evidenciada em ambos e associada à alteração funcional da imunidade mediada por células. Hipogamaglobulinemia é considerada como um possível fator predisponente para infecção criptocócica. A importância dos anticorpos no controle da infecção por Cryptococcus neoformans é discutida.

CD8+ T cell populations in common variable immunodeficiency

In a subgroup of CVID T cell abnormalities have been reported. Peripheral blood T lymphocytes from patients with common variable immunodeficiency (CVID) and blood donors were examined for expression of CD8alpha, CD8beta and CD28. In CVID, three CD8+ T cells could be defined: CD8beta(high)CD28+ (expressing CD8beta at a high median fluorescence intensity), CD8beta(low)CD28+ and CD8beta(low) CD28- cells. The number of CD8beta(low) cells was markedly increased compared to blood donors. After activation, CD8beta(high)CD28+ cells from cord blood differentiated into CD8beta(low) CD28- cells. Therefore, CD8beta(low) cells are induced by activation even in normal donors, but may reflect inflammatory activity in CVID.

B-cell function in canine X-linked severe combined immunodeficiency

Canine X-linked severe combined immunodeficiency (XSCID) is due to mutations in the common gamma (gammac) subunit of the IL-2, IL-4, IL-7, IL-9 and IL-15 receptors and has a similar clinical phenotype to human XSCID. We have previously shown that the block in T-cell development is more profound in XSCID dogs than in genetically engineered gamma c-deficient mice. In this study we evaluated the B-cell function in XSCID dogs. In contrast to the marked decrease in peripheral B-cells in gamma c-deficient mice, XSCID dogs have increased proportions and numbers of peripheral B-cells as observed in XSCID boys. Canine XSCID B-cells do not proliferate following stimulation with the T-cell-dependent B-cell mitogen, pokeweed mitogen (PWM); however, they proliferate normally in response to the T-cell-independent B-cell mitogen, formalin-fixed, heat-killed Staphylococcus aureus. Canine XSCID B-cells are capable of producing IgM but are incapable of normal class-switching to IgG antibody production as demonstrated by in vitro stimulation with PWM and immunization with the T-cell-dependent antigen, bacteriophage PhiX174. Similar results have been reported for XSCID boys. Thus, it appears that gamma c-dependent cytokines have differing roles in human and canine B-cell development than in the mouse making the XSCID dog a valuable model for studying the role of these cytokines in B-cell development and function.

Sarcoidosis and common variable immunodeficiency. A case of a malignant course of sarcoidosis in conjunction with severe impairment of the cellular and humoral immune system

The occurrence of sarcoidosis in combination with common variable immunodeficiency (CVID) has been described in a small number of patients. In these patients, sarcoidosis consisted of lymphadenopathy, mild to moderate pulmonary involvement and hepatosplenomegaly. However, severe and rapidly progressive pulmonary fibrosis in combination with a severe defect of the cellular and humoral immune system has not been described yet. In our patient, defects of the T and B cell system resulted in severe immunodeficiency. The defect of the humoral immune system was characterized by the impairment of specific antibody production in vivo. In addition, hypogammaglobulinemia with missing IgA and IgE along with a marked defect in IgM and IgG production was noted. There was a progressively reduced lymphocyte proliferation in response to T cell mitogens, while proliferation after specific IL-2 stimulation was normal. A Th1 lymphocyte-subset-like profile might thus play a role in the pathogenesis and might form the connecting link between sarcoidosis and CVID. This is the report of a so far new and unique combination of severe immunodeficiency and sarcoidosis also associated with a congenital dysmorphia consisting of a palatal cleft. The findings of the 40 patients with CVID and sarcoidosis reported so far are discussed in order to point out the typical features of patients with this uncommon syndrome.

Detection of Bruton's tyrosine kinase mutations in hypogammaglobulinaemic males registered as common variable immunodeficiency (CVID) in the Japanese Immunodeficiency Registry

CVID is frequently diagnosed in male and female individuals with hypogammaglobulinaemia of unknown aetiology. To examine the possibility that sporadic male cases with X-linked agammaglobulinaemia (XLA), which is caused by mutations in the Bruton's tyrosine kinase (Btk) gene, might be misregistered as having CVID, we employed a flow cytometric test to identify XLA in hypogammaglobulinaemic males registered as CVID in the Japanese Immunodeficiency Registry. From 30 male cases registered as having CVID between 1992 and 1998, we selected 21 males with low or unreported peripheral B cell counts. Blood samples could be obtained from 11 patients and their mothers. Using flow cytometric analysis, the Btk-deficient status in monocytes was demonstrated in seven out of nine cases with decreased numbers of peripheral B cells. The diagnosis of XLA was confirmed in each of the seven patients by demonstration of Btk gene mutations in the patients or cellular mosaicism in the mother. This study demonstrates misregistration of XLA as CVID.

Cdc42-interacting protein 4 mediates binding of the Wiskott-Aldrich syndrome protein to microtubules

The Wiskott-Aldrich syndrome is an inherited X-linked immunodeficiency characterized by thrombocytopenia, eczema, and a tendency toward lymphoid malignancy. Lymphocytes from affected individuals have cytoskeletal abnormalities, and monocytes show impaired motility. The Wiskott-Aldrich syndrome protein (WASP) is a multi-domain protein involved in cytoskeletal organization. In a two-hybrid screen, we identified the protein Cdc42-interacting protein 4 (CIP4) as a WASP interactor. CIP4, like WASP, is a Cdc42 effector protein involved in cytoskeletal organization. We found that the WASP-CIP4 interaction is mediated by the binding of the Src homology 3 domain of CIP4 to the proline-rich segment of WASP. Cdc42 was not required for this interaction. Co-expression of CIP4 and green fluorescent protein-WASP in COS-7 cells led to the association of WASP with microtubules. In vitro experiments showed that CIP4 binds to microtubules via its NH(2) terminus. The region of CIP4 responsible for binding to active Cdc42 was localized to amino acids 383-417, and the mutation I398S abrogated binding. Deletion of the Cdc42-binding domain of CIP4 did not affect the colocalization of WASP with microtubules in vivo. We conclude that CIP4 can mediate the association of WASP with microtubules. This may facilitate transport of WASP to sites of substrate adhesion in hematopoietic cells.

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.

Compartment syndrome in a patient with X-linked agammaglobulinaemia and ecthyma gangrenosum. Case report

Compartment syndrome is a surgical emergency that requires immediate decompression. We know of no documented cases that describe ecthyma gangrenosum as a primary cause of compartment syndrome. We present a case of a baby with x-linked agammaglobulinaemia who developed compartment syndrome associated with systemic Pseudomonas aeruginosa infection and ecthyma gangrenosum of the leg. He was treated by debridement and fasciotomies followed by primary closure and skin grafting and made an uneventful recovery.

Diversity, functionality, and stability of the T cell repertoire derived in vivo from a single human T cell precursor

In this report, we have analyzed the human T cell repertoire derived in vivo from a single T cell precursor. A unique case of X-linked severe combined immunodeficiency in which a reverse mutation occurred in an early T cell precursor was analyzed to this end. It was determined that at least 1,000 T cell clones with unique T cell receptor-beta sequences were generated from this precursor. This diversity seems to be stable over time and provides protection from infections in vivo. A similar estimation was obtained in an in vitro murine model of T cell generation from a single cell precursor. Overall, our results document the large diversity potential of T cell precursors and provide a rationale for gene therapy of the block of T cell development.

Cutting edge: lack of peripheral B cells and severe agammaglobulinemia in mice simultaneously lacking Bruton's tyrosine kinase and the B cell-specific transcriptional coactivator OBF-1

OBF-1 is a B cell-restricted transcriptional coactivator that is recruited to octamer-containing promoters by interacting with the POU domain of Oct-1 or Oct-2. We have shown earlier that mice lacking OBF-1 were dramatically impaired in their ability to mount humoral immune responses and did not develop germinal centers in the spleen; however, they had a largely normal B cell development in the bone marrow. In this study, we demonstrate that OBF-1-deficient mice also have an early defect in B cell development and show that OBF-1-/- immature B cells are greatly impaired at the transition from the bone marrow to the spleen. In addition, when the OBF-1 mutation is combined to a mutation in the gene encoding Bruton's tyrosine kinase, a striking phenotype is observed. These double-deficient animals lack peripheral B cells and have virtually no serum Igs, thus closely resembling human X chromosome-linked agammaglobulinemia.

Long-Term Chimerism and B-Cell Function After Bone Marrow Transplantation in Patients With Severe Combined Immunodeficiency With B Cells: A Single-Center Study of 22 Patients

We retrospectively analyzed the B-cell function and leukocyte chimerism of 22 patients with severe combined immunodeficiency with B cells (B+ SCID) who survived more than 2 years after bone marrow transplantation (BMT) to determine the possible consequences of BMT procedures, leukocyte chimerism, and SCID molecular deficit on B-cell function outcome. Circulating T cells were of donor origin in all patients. In recipients of HLA-identical BMT (n = 5), monocytes were of host origin in 5 and B cells were of host origin in 4 and of mixed origin in 1. In recipients of HLA haploidentical T-cell–depleted BMT (n = 17), B cells and monocytes were of host origin in 14 and of donor origin in 3. Engraftment of B cells was found to be associated with normal B-cell function. In contrast, 10 of 18 patients with host B cells still require Ig substitution. Conditioning regimen (ie, 8 mg/kg busulfan and 200 mg/kg cyclophosphamide) was shown neither to promote B-cell and monocyte engraftment nor to affect B-cell function. Eight patients with B cells of host origin had normal B-cell function. Evidence for functional host B cells was further provided in 3 informative cases by Ig allotype determination and by the detection, in 5 studied cases, of host CD27+ memory B cells as in age-matched controls. These results strongly suggest that, in some transplanted patients, host B cells can cooperate with donor T cells to fully mature in Ig-producing cells.

Long-term interferon alpha maintenance therapy for chronic hepatitis C infection in a patient with common variable immune deficiency

A 46-year-old woman with common variable immune deficiency acquired acute non-A, non-B hepatitis from contaminated intravenous gamma globulin in 1983. For 6 years she had fluctuating elevations of her serum aminotransferase levels. In 1990 her serum was documented to be hepatitis C virusribonucleic acid positive by polymerase chain reaction, and her liver biopsy revealed chronic hepatitis with early cirrhosis (Knodell score, 15 points). Hepatitis C virus genotyping indicated that she had been infected with the type 3 genotype. She subsequently underwent treatment with interferon alpha (IFN-alpha) for 1 year and experienced biochemical, virologic, and histologic (Knodell score, 9) suppression. She was continued on maintenance therapy for an additional 7 years, with sustained biochemical and virologic suppression. During the sixth year of therapy, complications of portal hypertension were noted with mild ascites and eventually bleeding esophageal varices. This case report documents a favorable biochemical, virologic, and histologic response to IFN-alpha therapy in this setting; supports the notion that the natural progression of hepatitis C virus infection may be more aggressive in patients with common variable immune deficiency; and, although complications of portal hypertension eventually occurred, the suppressive maintenance IFN therapy may have delayed their onset. The future establishment of the long-term effects of IFN therapy on important clinical outcomes is necessary to understand better its therapeutic benefit in chronic hepatitis C infection.

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.

Canine X-linked severe combined immunodeficiency

Canine X-linked severe combined immunodeficiency (XSCID) is due to mutations in the common gamma (gamma c) subunit of the IL-2, IL-4, IL-7, IL-9 and IL-15 receptors. The most striking clinical feature is a failure to thrive or 'stunted' growth. Recurrent or chronic infections begin at the time of decline of maternal antibody, usually between six and eight weeks of age. Affected dogs rarely survive past three to four months of age. The major pathologic feature of canine XSCID is a small, dysplastic thymus. Grossly identifiable lymph nodes, tonsils, and Peyer's patches are absent in XSCID dogs. During the neonatal period, XSCID dogs have few, if any, peripheral T cells and increased number of peripheral B cells. Some XSCID dogs do develop phenotypically mature, nonfunctional T cells with age, however, the absolute number of peripheral T cells remain significantly decreased compared to age-matched normal dogs. An interesting finding is that as soon as T cells begin to appear in XSCID dogs they rapidly switch from a CD45RA+ (naive) phenotype to a CD45RA- (activated or memory phenotype). One of the characteristic findings in XSCID dogs is an absent or markedly depressed blastogenic response of T cells in response to stimulation through the T cell receptor and when the necessary second messengers for cellular proliferation are directly provided that by-pass signals delivered through ligand-receptor interaction. The proliferative defect is due to the inability of T cells to express a functional IL-2 receptor. Canine XSCID B cells do not proliferate following stimulation with T cell-dependent B cell mitogens, however, they proliferate normally in response to T cell-independent B cell mitogens. Canine XSCID B cells are capable of producing IgM but are incapable of class-switching to IgG antibody production following immunization with the T cell-dependent neoantigen, bacteriophage phiX174. The number of thymocytes in the XSCID thymus is approximately 0.3% of the thymocytes present in the thymus of age-matched normal dogs. The proportion of CD4-CD8- thymocytes in XSCID dogs is increased 3.5-fold and the CD4+CD8+ population is decreased 2.3-fold. These findings demonstrate that (1) a functional gamma c is required for normal B and T cell function, (2) early T cell development is highly dependent upon a functional gamma c, and (3) B cell development can occur through a gamma c-independent pathway.

BALB/c.CBA/N mice carrying the defective Btk(xid) gene are resistant to pristane-induced plasmacytomagenesis

The X-chromosome from the CBA/N mouse which carries the defective Bruton's tyrosine kinase (Btk) allele (Xxid) has been introgressively backcrossed onto the plasmacytoma (PCT) induction-susceptible BALB/cAN. Inbred BALB/c.CBA/N-xid/xid (C.CBA/N) mice raised and maintained in our conventional colony were given three 0.5 ml injections of pristane and were highly refractory to PCT induction. Only one PCT was found among 59 mice followed for > or =300 days. Twenty mice were examined at day 200 for foci of plasma cells in the oil granuloma. Ten mice had small foci of plasma cells, most of which were plasmacytotic, embedded in the inflammatory oil granuloma. In one there were multiple foci, but most of the mice had only one or two foci. F1 hybrid XxidY males derived from CBA/N females crossed to BALB/cAnPt were also resistant to PCT induction, while heterozygous and homozygous XY males were susceptible. C.CBA/N mice can develop extensive mucosal plasma cells as well as plasma cell accumulations in oil granuloma tissue, but the precursors of these plasma cells do not give rise to PCT in genetically susceptible hosts. The failure of C.CBA/N mice to develop PCT is probably due to the elimination of B cell clones that can be perpetuated by repeated exposure to thymus-independent type 2 antigens.

Lymphoproliferative disorder of fetal origin presenting as oligohydramnios

Lymphoma involving the placenta or fetus remains a very rare event. All cases reported to date have shown the lymphoma cells to be of maternal origin in that the tumor cells have preferentially involved the intervillous spaces with sparing of the villi and fetal circulation. We report a novel case of a monoclonal primary placental Epstein-Barr virus (EBV)-associated B-cell lymphoma of fetal origin. The placenta of a 20-week stillborn fetus born to a 19-year-old gravida 1 para 0 woman, presenting with oligohydramnios, showed a large cell infiltrate confined within villi and sparing the intervillous spaces, indicative of preferential involvement of the fetal circulation. Necropsy did not show any other site of involvement by malignant lymphoma or other abnormalities. Immunophenotypic studies showed the tumor cells to be of B-cell phenotype with a relatively high proliferation rate. EBV EBER1 RNA was identified in more than 95% of tumor cells, and polymerase chain reaction studies showed EBV EBNA1 strain type A and wildtype EBV LMP1. Analysis of the immunoglobulin heavy chain by polymerase chain reaction showed a monoclonal B-cell population. In situ hybridization studies using a commercially available probe directed at repeated sequences on the human Y chromosome showed a single intense signal within trophoblastic epithelium and lymphoma cells, indicative of male origin. The mother remains in good health 11 months after delivery.

Mutations That Cause the Wiskott-Aldrich Syndrome Impair the Interaction of Wiskott-Aldrich Syndrome Protein (WASP) with WASP Interacting Protein

Wiskott-Aldrich syndrome (WAS) is an X-linked recessive disorder characterized by thrombocytopenia, eczema, immune deficiency, and a proclivity toward lymphoid malignancy. Lymphocytes of affected individuals show defects of activation, motility, and cytoskeletal structure. The disease gene encodes a 502-amino acid protein named the WAS protein (WASP). Studies have identified a number of important interactions that place WASP in a role of integrating signaling pathways with cytoskeletal function. We performed a two-hybrid screen to identify proteins interacting with WASP and cloned a proline-rich protein as a specific WASP interactor. Our clone of this protein, termed WASP interacting protein (WIP) by others, shows a difference in seven amino acid residues, compared with the previously published sequence revealing an additional profilin binding motif. Deletion mutant analysis reveals that WASP residues 101–151 are necessary for WASP-WIP interaction. Point mutant analyses in the two-hybrid system and in vitro show impairment of WASP-WIP interaction with three WASP missense mutants known to cause WAS. We conclude that impaired WASP-WIP interaction may contribute to WAS.

Autoimmunity and extranodal lymphocytic infiltrates in lymphoproliferative disorders

OBJECTIVE

To examine the relationship between autoimmunity and extranodal lymphocytic infiltrates in different lymphoproliferative disorders with immunoglobulin alterations.

SUBJECTS AND DESIGN

A clinical review combined with a retrospective cohort study of 380 patients, 28 with monoclonal gammopathy of undetermined significance, three with common variable immunodeficiency, 147 with chronic lymphocytic leukaemia, 57 with Waldenström's macroglobulinaemia and 145 with non-Hodgkin's malignant lymphoma.

SETTING

A university hospital and The State Serum Institute in Copenhagen.

INTERVENTION

Clinical examination of each patient with special attention to chronic inflammatory and autoimmune manifestations. Biopsies were taken from non-infectious infiltrates, some of which were additionally tested with PCR analysis for gene rearrangements. Serological screening with a test battery for various autoantibodies was used in combination with techniques for the detection of M-components and monoclonal B-cell proliferation.

MAIN OUTCOME MEASURES

Clinical and/or serological autoimmune manifestations, M-component and other immunoglobulin alterations, and inflammatory tissue changes were studied in patients with chronic inflammatory, polyclonal or oligoclonal pseudolymphomas and in monoclonal, malignant extranodal lymphomas.

RESULTS

In 380 consecutive patients, 49 (12.9%) had extranodal manifestations, of whom 47 also had autoimmune manifestations. Nearly half of the 47 patients had more than one autoimmune manifestation. There was a strong correlation between clinical signs and corresponding autoantibodies such as anti-SSA and -SSB antibodies in Sjögren's syndrome (10 cases), antithyroid peroxidase antibodies in thyroiditis and Graves' disease (10 cases), and parietal cell antibodies in gastric ulcers with maltoma (12 cases). Clinical and serological signs of autoimmunity correlated strongly with female sex (34, 72% women; and 13, 28% men) and with immunoglobulin alterations.

CONCLUSIONS

To our knowledge this is the first systematic review of B-lymphoproliferative and autoimmune disorders indicating that pseudolymphoma and malignant lymphomas, including maltomas, may develop in the context of a permanent autoantigenic drive.

Immunodeficiency due to a unique protracted developmental delay in the B-cell lineage

A unique immune deficiency in a 24-month-old male characterized by a transient but protracted developmental delay in the B-cell lineage is reported. Significant deficiencies in the number of B cells in the blood, the concentrations of immunoglobulins in the serum, and the titers of antibodies to T-dependent and T-independent antigens resolved spontaneously by the age of 39 months in a sequence that duplicated the normal development of the B-cell lineage: blood B cells followed by immunoglobulin M (IgM), IgG, IgA, and specific IgG antibodies to T-independent antigens (pneumococcal polysaccharides). Because of the sequence of recovery, the disorder could have been confused with other defects in humoral immunity, depending on when in the course of disease immunologic studies were conducted. Investigations of X-chromosome polymorphisms suggested that the disorder was not X linked in that the mother appeared to have identical X chromosomes. An autosomal recessive disorder involving a gene that controls B-cell development and maturation seems more likely. In summary, this case appears to be a novel protracted delay in the development of the B-cell lineage, possibly due to an autosomal recessive genetic defect.

Sequence of testing for monoclonal gammopathies

The first test for recognition of monoclonal gammopathies should be serum protein electrophoresis with high-resolution agarose gel. Serum protein electrophoresis should be performed whenever multiple myeloma, Waldenström's macroglobulinemia, primary amyloidosis, or a related disorder is suspected. Immunofixation is critical for the differentiation of a monoclonal from a polyclonal increase in immunoglobulins. Quantitation of immunoglobulins should be performed with a rate nephelometer. The viscosity of serum should be measured if the patient has signs or symptoms of hyperviscosity syndrome. A 24-hour urine specimen should be obtained for determination of the total amount of protein excreted each day. Immunofixation of the urine should be performed on every patient who has an M-protein level greater than 1.5 g/dL (15 g/L) in the serum or in whom multiple myeloma, Waldenström's macroglobulinemia, primary amyloidosis, or a related disorder is suspected.

Adhesion molecules in common variable immunodeficiency (CVID)--a decrease in L-selectin-positive T lymphocytes

CVID is immunologically characterized by defective antibody production. Various additional immunological abnormalities have been reported, but little is known of the role of adhesion molecules in CVID. In 31 CVID patients serum levels of L-selectin (CD62L), vascular cell adhesion molecule-1 (VCAM-1) (CD106) and intercellular adhesion molecule-1 (ICAM-1) (CD54) were significantly elevated compared with controls. In 15 CVID patients investigated, the number of L-selectin-positive cells was significantly reduced in both CD4+ and CD8+ lymphocytes compared with controls, and these changes were observed in both CD45RA+ and CD45RO+ subsets. In CD19+ lymphocytes the percentage of ICAM-1+ cells was significantly increased compared with controls. Fifty percent of the patients had splenomegaly. These patients demonstrated even higher serum levels of adhesion molecules, a lower percentage of L-selectin-positive and a higher percentage of CD38+ cells in many T lymphocyte subsets compared with both other CVID patients and controls. Finally, in this patient group the percentage of L-selectin-positive CD19+ lymphocytes was significantly reduced compared with both other patients and controls. These findings indicate a state of ongoing T lymphocyte activation in CVID, especially in the subgroup of patients with splenomegaly, which may contribute to the impaired antimicrobial defence observed in these patients.

Biology of the interleukin-2 receptor

Studies of the biology of the IL-2 receptor have played a major part in establishing several of the fundamental principles that govern our current understanding of immunology. Chief among these is the contribution made by lymphokines to regulation of the interactions among vast numbers of lymphocytes, comprising a number of functionally distinct lineages. These soluble mediators likely act locally, within the context of the microanatomic organization of the primary and secondary lymphoid organs, where, in combination with signals generated by direct membrane-membrane interactions, a wide spectrum of cell fate decisions is influenced. The properties of IL-2 as a T-cell growth factor spawned the view that IL-2 worked in vivo to promote clonal T-cell expansion during immune responses. Over time, this singular view has suffered from increasing appreciation that the biologic effects of IL-2R signals are much more complex than simply mediating T-cell growth: depending on the set of conditions, IL-2R signals may also promote cell survival, effector function, and apoptosis. These sometimes contradictory effects underscore the fact that a diversity of intracellular signaling pathways are potentially activated by IL-2R. Furthermore, cell fate decisions are based on the integration of multiple signals received by a lymphocyte from the environment; IL-2R signals can thus be regarded as one input to this integration process. In part because IL-2 was first identified as a T-cell growth factor, the major focus of investigation in IL-R2 signaling has been on the mechanism of mitogenic effects in cultured cell lines. Three critical events have been identified in the generation of the IL-2R signal for cell cycle progression, including heterodimerization of the cytoplasmic domains of the IL-2R beta and gamma(c) chains, activation of the tyrosine kinase Jak3, and phosphorylation of tyrosine residues on the IL-2R beta chain. These proximal events led to the creation of an activated receptor complex, to which various cytoplasmic signaling molecules are recruited and become substrates for regulatory enzymes (especially tyrosine kinases) that are associated with the receptor. One intriguing outcome of the IL-2R signaling studies performed in cell lines is the apparent functional redundancy of the A and H regions of IL-2R beta, and their corresponding downstream pathways, with respect to the proliferative response. Why should the receptor complex induce cell proliferation through more than one mechanism or pathway? One possibility is that this redundancy is an unusual property of cultured cell lines and that primary lymphocytes require signals from both the A and the H regions of IL-2R beta for optimal proliferative responses in vivo. An alternative possibility is that the A and H regions of IL-2R beta are only redundant with respect to proliferation and that each region plays a unique and essential role in regulating other aspects of lymphocyte physiology. As examples, the A or H region could prove to be important for regulating the sensitivity of lymphocytes to AICD or for promoting the development of NK cells. These issues may be resolved by reconstituting IL-2R beta-/-mice with A-and H-deleted forms of the receptor chain and analyzing the effect on lymphocyte development and function in vivo. In addition to the redundant nature of the A and H regions, there remains a large number of biochemical activities mediated by the IL-2R for which no clear physiological role has been identified. Therefore, the circumstances are ripe for discovering new connections between molecular signaling events activated by the IL-2R and the regulation of immune physiology. Translating biochemical studies of Il-2R function into an understanding of how these signals regulate the immune system has been facilitated by the identification of natural mutations in IL-2R components in humans with immunodeficiency and by the generation of mice with targeted mutations in these gen

Downregulation of the CD95 receptor and defect CD40-mediated signal transduction in B-chronic lymphocytic leukemia cells

Cross-linking of the CD40 receptors has been shown to induce protein tyrosine kinases (PTK) phosphorylation and prevent apoptosis in Bcl-2 negative germinal center B cells. The expression of CD40 on B chronic lymphocytic leukemia (B-CLL) cells was found to be similar to that of normal B cells. Activation of normal B cells with soluble anti-CD40 monoclonal antibody (mAb) induced tyrosine phosphorylation, prolonged survival and prevented apoptosis. However, activation of CD40 on B-CLL cells using soluble anti-CD40 mAb does not influence survival or apoptosis. Normal B cells entered apoptosis when cultured in the presence of soluble anti-CD95 mAb. This process was independent of PTK activity. On B-CLL cells, the CD95 molecules were downregulated and a transient PTK signal was observed when cross-linking of the receptor by soluble anti-CD95 mAb occurred. Interestingly, B-CLL cells did not enter apoptosis in the presence of anti-CD95 mAb. Our study indicates that survival signals mediated through the CD40 molecule and death signals mediated through the CD95 molecule used different intracellular pathways in control donor B cells. In contrast, B-CLL cells do not respond to these signals. The leukemic B cells showed a defective CD40-mediated signal transduction and downregulated CD95 receptor expression. As a consequence, no apoptosis could be induced in B-CLL cells by a soluble anti-CD95 mAb. The abnormalities of these receptors may contribute to the long-lived status of B-CLL cells.

Prolonged replication of a type 1 vaccine-derived poliovirus in an immunodeficient patient

VP1 sequences were determined for poliovirus type 1 isolates obtained over a 189-day period from a poliomyelitis patient with common variable immunodeficiency syndrome (a defect in antibody formation). The isolate from the first sample, taken 11 days after onset of paralysis, contained two poliovirus populations, differing from the Sabin 1 vaccine strain by approximately 10%, differing from diverse type 1 wild polioviruses by 19 to 24%, and differing from each other by 5.5% of nucleotides. Specimens taken after day 11 appeared to contain only one major poliovirus population. Evolution of VP1 sequences at synonymous third-codon positions occurred at an overall rate of approximately 3.4% per year over the 189-day period. Assuming this rate to be constant throughout the period of infection, the infection was calculated to have started approximately 9.3 years earlier. This estimate is about the time (6. 9 years earlier) the patient received his last oral poliovirus vaccine dose, approximately 2 years before the diagnosis of immunodeficiency. These findings may have important implications for the strategy to eliminate poliovirus immunization after global polio eradication.

Wiskott-Aldrich syndrome protein-deficient mice reveal a role for WASP in T but not B cell activation

The Wiskott-Aldrich syndrome (WAS) is a human X-linked immunodeficiency resulting from mutations in a gene (WASP) encoding a cytoplasmic protein implicated in regulating the actin cytoskeleton. To elucidate WASP function, we disrupted the WASP gene in mice by gene-targeted mutation. WASP-deficient mice showed apparently normal lymphocyte development, normal serum immunoglobulin levels, and the capacity to respond to both T-dependent and T-independent type II antigens. However, these mice did have decreased peripheral blood lymphocyte and platelet numbers and developed chronic colitis. Moreover, purified WASP-deficient T cells showed markedly impaired proliferation and antigen receptor cap formation in response to anti-CD3epsilon stimulation. Yet, purified WASP-deficient B cells showed normal responses to anti-Ig stimulation. We discuss the implications of our findings regarding WASP function in receptor signaling and cytoskeletal reorganization in T and B cells and compare the effects of WASP deficiency in mice and humans.

High-efficiency gene transfer into normal and adenosine deaminase-deficient T lymphocytes is mediated by transduction on recombinant fibronectin fragments

Primary human T lymphocytes are powerful targets for genetic modification, although the use of these targets in human gene therapy protocols has been hampered by low levels of transduction. We have shown previously that significant increases in the transduction of hematopoietic stem and progenitor cells with retroviral vectors can be obtained by the colocalization of the retrovirus and target cells on specific fibronectin (FN) adhesion domains (H. Hanenberg, X. L. Xiao, D. Dilloo, K. Hashino, I. Kato, and D. A. Williams, Nat. Med. 2:876-882, 1996). We studied the transfer of genes into primary T lymphocytes by using FN-assisted retroviral gene transfer. Activated T lymphocytes were infected for three consecutive days on the recombinant FN fragment CH-296 with a retroviral vector encoding the murine B7-1 protein. Transduced lymphocytes were analyzed for murine B7-1 expression, and it was found that under optimal conditions, 80 to 89% of the CD3+ lymphocytes were transduced. Gene transfer was predominantly augmented by the interaction between VLA-4 on the T lymphocytes and the FN adhesion site CS-1. Adenosine deaminase (ADA)-deficient primary T lymphocytes transduced on CH-296 with a retrovirus encoding murine ADA (mADA) exhibited levels of mADA activity severalfold higher than the levels of the endogenous human ADA protein observed in normal human T lymphocytes. Strikingly, the long-term expression of the transgene was dependent on the activation status of the lymphocytes. This approach will have important applications in human gene therapy protocols targeting primary T lymphocytes.

Discoid lupus erythematosus associated with a primary immunodeficiency syndrome showing features of non-X-linked hyper-IgM syndrome

Hyper-IgM (HIM) syndrome is a rare primary immunodeficiency disorder. Approximately 120 cases have been described in the literature world-wide. Features of HIM include low serum IgG, a very low IgA with normal or high IgM levels. Autoimmune phenomena are recognized associations but connective tissue disorders have so far not been described in HIM patients. We report the case of a 19-year-old Indian woman with an immunodeficiency syndrome characteristic of non-X-linked HIM who developed discoid lupus erythematosus. Anti-double-stranded DNA antibodies were negative. Antibodies to extractable nuclear antigens were positive for Ro and nRNP, with evidence that they were of both IgG and IgM class. Treatment with hydroxychloroquine and topical steroids was successful.