T and B lymphocyte abnormalities in bone marrow biopsies of common variable immunodeficiency

In common variable immunodeficiency (CVID) defects in early stages of B-cell development, bone marrow (BM) plasma cells and T lymphocytes have not been studied systematically. Here we report the first morphologic and flow cytometric study of B- and T-cell populations in CVID BM biopsies and aspirates. Whereas the hematopoietic compartment showed no major lineage abnormalities, analysis of the lymphoid compartment exhibited major pathologic alterations. In 94% of the patients, BM plasma cells were either absent or significantly reduced and correlated with serum immunoglobulin G levels. Biopsies from CVID patients had significantly more diffuse and nodular CD3(+) T lymphocyte infiltrates than biopsies from controls. These infiltrates correlated with autoimmune cytopenia but not with other clinical symptoms or with disease duration and peripheral B-cell counts. Nodular T-cell infiltrates correlated significantly with circulating CD4(+)CD45R0(+) memory T cells, elevated soluble IL2-receptor and neopterin serum levels indicating an activated T-cell compartment in most patients. Nine of 25 patients had a partial block in B-cell development at the pre-B-I to pre-B-II stage. Because the developmental block correlates with lower transitional and mature B-cell counts in the periphery, we propose that these patients might form a new subgroup of CVID patients.     

Characterization of common variable immunodeficiency: identification of a subset of patients with distinctive immunophenotypic and clinical features

The peripheral blood lymphocyte surface markers and clinical features of 38 patients with common variable immunodeficiency (CVID) were assessed. These studies identified a subset of CVID consisting of 14 of the 38 patients with a distinctive T-cell immunophenotype and clinical findings. The phenotypic changes were characterized by an abnormally low CD4/CD8 ratio (less than or equal to 0.9) due primarily to a significant increase in CD8 T cells. In addition, there was an expansion in CD8 T cells coexpressing CD57 and increased expression of the activation markers HLA-DR and interleukin-2 receptor (IL-2R) by these cells. This group of immunophenotypically abnormal CVID patients also had characteristic clinical features, including splenomegaly (P less than .02) and in vivo T-cell dysfunction based on the evaluation of delayed-type hypersensitivity (P less than .05). Approximately 71% of these patients had splenomegaly and 42% were anergic in contrast to the remaining group of CVID patients, in which 29% had splenomegaly and 7% were anergic. These findings define a subgroup of CVID patients that have specific immunophenotypic features and functional T-cell abnormalities.     

Clinical and Immunological Spectrum of Common Variable Immunodeficiency (CVID)

We have analysed data from 150 patients initially classified as having CVID. About 10% had laboratory abnormalities suggesting known single gene disorders (eg: hyper-IgM syndrome), and in a few a genetic defect has been confirmed. We have attempted to sub-classify the remaining patients by analysis of their circulating lymphocytes. B lymphocyte markers have been used to estimate the numbers of circulating immature and class switched B cells; there is an association between the presence of high relative numbers of immature circulating B cells, splenomegaly and autoimmune disease. About 25% of CVID patients have a moderate CD4+ T lymphopenia, sometimes with a relative expansion of CD8+ T cells. About 30% of CVID patients have persistent relatively high levels of circulating CD8+ T cells binding immunogenic peptides from EBV or CMV. Many of these patients also have high relative numbers of circulating CD8+ perforin positive T cells, and there is evidence that these cells may be responsible for neutropenia or inflammatory bowel disease in some patients. The clinical spectrum of CVID is diverse, with some patients suffering from few infections, and over 50% have evidence of structural lung damage. About 25% of UK patients have chronic inflammation in various organs, particularly the lungs, liver and spleen, often with granulomatous changes. Steroids are used to treat many of the patients with chronic inflammatory complications, although trials are in progress with anti-TNF agents. The incidence of these inflammatory complications is different between countries, being rare in Sweden. Attempts to correlate clinical phenotypes with the laboratory abnormalities described above have been disappointing, suggesting that unknown genetic factors unrelated to the cause of the immunodeficiency determine the complications; attempts to identify some of these factors will be discussed. Finally a provisional scheme to sub classify CVID patients according to lymphocyte abnormalities will be presented, the purpose being to focus the screening of candidate genes causing CVID to specific subsets of patients.     

Skin-derived interleukin-7 contributes to the proliferation of lymphocytes in cutaneous T-cell lymphoma

Cutaneous T-cell lymphomas (CTCLs) are malignancies of T cells that have a special affinity for the skin. We have previously reported that much of the T-cell receptor repertoire is altered in CTCL, and both malignant and nonmalignant clones are numerically expanded, presumably in response to T-cell trophic cytokines. We therefore examined levels of the T-cell trophic cytokines IL-2, IL-4, IL-7, IL-12, IL-13, and IL-15 in plasma in 93 CTCL patients and healthy controls. Only IL-7 levels were elevated in CTCL. We next looked at lesional skin from patients with CTCL and found elevated levels of IL-7 mRNA. Explant cultures of normal and lesional CTCL skin biopsies revealed significantly more IL-7 protein production in CTCL skin. Additionally, cultures of CTCL skin released greater numbers of T cells than normal skin; this was blocked by the addition of an IL-7 neutralizing antibody. Finally, these cultures induced proliferation of normal peripheral skin-homing T cells that were added to the cultures. These observations led us to postulate that IL-7 produced by skin cells contributes to the survival and proliferation of T cells within skin lesions and is likely the source of elevated circulating IL-7 in CTCL.     

Common variable immunodeficiency is associated with defective functions of dendritic cells

Common variable immunodeficiency (CVID) is characterized by hypogammaglobulinemia and defects in T-cell functions that could be primary or secondary. We addressed whether CVID is associated with impairment in the dendritic cell (DC) compartment, as DCs play a central role in the development of adaptive immunity. We demonstrate that DCs from CVID patients display severely perturbed differentiation, maturation, and function, and express markedly reduced levels of the costimulatory molecules that are critical for T-cell stimulation. Patients' DCs induced weak proliferation of allogeneic T cells and produced significantly low amounts of interleukin-12 (IL-12) upon CD40 signaling. Multiple defects in the immune system, including malfunctioning of DCs, appear to be prominent features of CVID patients. Impairment in both the innate and adaptive compartments of the immune system may thus cumulatively account for the inability of CVID patients to eradicate pathogens through conventional immune pathways, thus resulting in an increased risk for recurrent bacterial infections.     

High production of IL-18 by dendritic cells induced by sera from patients with primary antibody deficiency

Predominantly antibody deficiencies are a category of primary immunodeficiency diseases, which consist of several rare disorders such as common variable immunodeficiency (CVID) and X-linked agammaglobulinemia (XLA). We evaluated the effects of CVID and XLA patients' sera as a source of microenviromental factors on maturation and function of monocyte-derived DCs. Blood was collected from 10 CVID and 5 XLA patients before immunoglobulin replacement therapy and also from 8 healthy volunteers in order to obtain necessary sera for this study. Monocyte derived DCs were generated from blood cells obtained from healthy volunteers in the presence of GM-CSF, IL-4 and 10% serum concentrations from cases and controls. Immature DCs were incubated with monocyte conditioned medium (MCM) and TNF- in order to generate mature DCs. Interleukin 18 (IL-18) production by CD40L-activated mature DCs was measured after 24 hours of culture in vitro.IL-18 production by DCs generated in the presence of CVID and XLA patients' sera were 6.75+/-2.59 and 7.08+/-1.75 ng/ml, respectively, which were significantly higher than normal serum conditioned DCs (3.55+/-0.68) ng/ml. These results suggest that the sera of patients with predominantly antibody deficiencies may contain soluble factor(s) that can induce a significant increase in IL-18 production by DCs.     

The malignant B cells from B-chronic lymphocytic leukemia patients release TAC-soluble interleukin-2 receptors

Both membrane (p55) and soluble (p45) forms of TAC-reactive interleukin- 2 receptor (IL-2R) are expressed and/or released by activated lymphocytes or monocytes. Previous work has detected increased levels of circulating, TAC-soluble IL-2R (soluble TAC antigen) in the serum of most B-cell chronic lymphocytic leukemia (B-CLL) patients. We detected soluble TAC antigen in B-CLL patients (mean of 3,332 U/mL v 410 for controls). Serum soluble TAC antigen levels increased with stage (mean value of 1,187 U/mL for stage 0 v 2,527 for stage 2 and 5,410 for stages 3 and 4). We next attempted to determine whether the elevated serum levels of soluble TAC antigen in B-CLL patients might result from shedding or secretion of the receptor from the circulating, malignant B cells. Purified, malignant B cells from B-CLL patients were capable of producing easily detectable soluble TAC antigen after 48 hours of in vitro culture (range of 60 to 1,563 U/mL). IL-2R production by CLL B cells was dose dependent in most patients over a concentration of 10 x 10(6) to 60 x 10(6)/mL. In contrast, there was little or no detectable soluble TAC antigen when highly purified T cells from the same patients were cultured. Finally, despite elaboration of soluble IL-2R by CLL B cells, membrane expression of B-cell IL-2R was detected in only six of 11 patients. Thus, the cellular source of the elevated serum IL-2R levels is the malignant CLL B cell. Taken together these data suggest that (a) the malignant CLL B cell is "activated" in terms of release of soluble IL-2R and may serve as a tumor marker in this disease and (b) the elevated levels of circulating IL-2R may be an associated factor in the cellular immunodeficiency noted in B-CLL patients.     

Elevated levels of activated CD4 T cells in common variable immunodeficiency: association with clinical findings

BackgroundCommon variable immunodeficiency (CVID) is a very heterogeneous syndrome defined by impaired immunoglobulin production. The primary defect remains unknown, but many reports describe peripheral blood T and B lymphocyte dysfunctions in a substantial proportion of CVID patients. Immunophenotypic alterations on memory B lymphocytes correlate with clinical findings. A B-cell-oriented classification principle of the patients has been proposed.Methods and resultsWe investigated the expression of activation surface molecules on CD4 and CD8 T-cells from 14 patients with CVID, 6 non-CVID hypogammaglobulinemic patients with recurrent infections, 47 asymptomatic HIV-positive patients without AIDS defining conditions and 23 healthy subjects. Lymphocyte subsets were analysed by three-colour flow cytometry. Monoclonal panel: CD38-FITC/HLADR-PE/CD4 or CD8-PerCP. In CVID patients serum levels of CD4 T-cells co-expressing the activation marker HLA-DR [CD4 + DR + (34 %), CD4 + CD38 + DR + (18 %)] were significantly elevated compared with controls. Significant increases in CD8 + DR + (54%), CD8 + CD38 + (43 %) and CD8 + CD38 + DR + (29 %) T-cells were observed in comparison with healthy controls. CVID patients with splenomegaly, lower pre-infusion IgG levels (< 600 mg/dl), autoimmune or lymphoproliferative conditions demonstrated even higher levels of CD4 + CD38 + DR + T cells (22, 22, 21 and 21 % respectively) compared with other CVID patients (13, 13, 15 and 15 % respectively).ConclusionThese findings indicate a state of ongoing T lymphocyte activation which is associated with clinical findings frequently observed in CVID.     

Systemic lupus erythematosus as a first presentation of common variable immunodeficiency associated with infrequent mannose-binding lectin gene polymorphisms

The association of common variable immunodeficiency (CVID) and systemic lupus erythematosus (SLE) is infrequent. Mannose-binding lectin (MBL) has been shown to play a role in CVID and SLE. The purpose of this study is to describe two cases of CVID who presented as SLE and also evaluate the presence of MBL polymorphisms and MBL serum levels in those patients. In both patients, SLE was the first manifestation of CVID. In these patients the SLE immunological markers and disease activity disappeared after the development of CVID. They carried the very infrequent MBL haplotype 4Q-57Glu. One of them had a homozygous genotype, whereas the other patient was heterozygous and also presented the haplotype 4P-57Glu that had never been previously detected. Interestingly, this last patient was presenting frequent respiratory tract infections, developed bronchiectasis and had low levels of circulating MBL. These results may support the role of MBL in the development of autoimmunity in CVID. Further genetic studies are needed to clarify the role of the MBL polymorphisms in the development of autoimmunity in CVID.     

Granulomatous disease in common variable immunodeficiency

PURPOSE: Common variable immunodeficiency (CVID), defined by defective production of immunoglobulins, is the most common primary immunodeficiency in adulthood requiring a medical follow-up. Repeated bacterial infections and/or autoimmune manifestations and/or benign lymphoproliferation (including follicular hyperplasia and/or granulomatous disease) are the hallmark of the disease. This review aims at describing recent advances in the understanding and treatment of granulomatous disease in CVID. CURRENT KNOWLEDGE AND KEY POINTS: Clinical features of granulomatous disease in CVID can mimic sarcoidosis, remarkable by the low levels of circulating immunoglobulins. Granulomas may be found in several organs in a single patient, and the main features are pulmonary, lymphoid, cutaneous, hepatic or splenic. The features of CVID is remarkable by the high frequency of autoimmune diseases complicating the immunodeficiency. Some immunological abnormalities have been described in such patients, including lymphopenia, decreased T-cells proliferations to mitogens and antigens. Rare polymorphisms in the gene encoding TNFalpha (Tumor Necrosis Factor) have been identified in CVID patients with granulomatous disease. FUTURE PROSPECTS AND PROJECTS: The evolution of the disease is severe, particularly when the lung is involved. Treatment consists in immunoglobulins substitution, immunosuppressive agents (corticosteroids, cyclophosphamide) and anti-TNFalpha antibodies. These treatments are difficult to manage in such immunocompromised patients.     

Idiopathic CD4+ T lymphocytopenia is associated with increases in immature/transitional B cells and serum levels of IL-7

Idiopathic CD4+ T lymphocytopenia (ICL) is a rare heterogeneous disorder defined by CD4+ T-cell counts below 300 cells/muL in the absence of human immunodeficiency virus (HIV) infection or other known immune deficiency disorders. Here, we report the expansion of immature/transitional B cells in patients with ICL, which is associated with elevated serum levels of IL-7. Both the percentage of immature/transitional B cells and levels of IL-7 were inversely correlated with levels of CD4+ T-cell counts and directly correlated to each other. Further analyses of B cells indicated that, in contrast to the activating effects of HIV disease on mature B cells, the expansion of immature/transitional B cells in patients with ICL occurred at the expense of memory B cells. These findings extend previous reports on primary immunodeficiencies as well as HIV disease by suggesting that CD4+ T-cell lymphopenia has an impact on human B-cell development either directly or indirectly via the associated elevation of IL-7 levels.     

Interleukin-7 in rheumatoid arthritis

Recent data from several groups demonstrate high levels of IL-7 in the joints of RA patients, but much lower levels in OA. In contrast, circulating levels of IL-7 in RA remain a point of debate. IL-7 has many roles in T cell, dendritic cell and bone biology in humans. Reduced levels of circulating IL-7 probably underlie a number of the dysfunctions associated with circulating T cells in RA and may provide a mechanism for some of the unexplained systemic manifestations of the disease. However, IL-7 in the joint may have a more sinister role, contributing to a vicious cycle perpetuating inflammation. Typically, IL-1beta and TNF-alpha increase the stromal production of IL-7 and in turn, IL-7 up-regulates the production of TNF-alpha by macrophages. Most importantly, IL-7 induces the production of osteoclastogenic cytokines by T cells, leading to the maturation of osteoclasts and therefore bone destruction. By linking the stroma with innate and adaptive immunity in RA, IL-7 may be directing the cellular network, leading to chronic inflammation and joint destruction. Blocking IL-7 may well therefore be of therapeutic value.     

Cytokine profiles and T cell function in acute coronary syndromes

AIMS: In advanced human atherosclerotic plaques infiltrating T cells congregate at sites of plaque rupture. However, little is known about the systemic activation of circulating T cells in acute coronary syndromes as a prerequisite for recruitment to atherosclerotic lesions. METHODS AND RESULTS: As a measure for specific lymphocyte activation we analyzed IFN-gamma production of T cells after stimulation with a superantigen and expression of CXCR-3 and CCR-3 in patients with acute myocardial infarction (AMI), unstable angina (uAP) or stable angina (sAP). Furthermore, concentrations of the circulating cytokines interleukin (IL)-1, IL-6, IL-1beta, IL-12 p70 and RANTES that modify T cell function were measured. In uAP an increased Th1 and a decreased Th2 response was identified by enhanced interferon-gamma generation of T lymphocytes, increased levels of IL-1beta, IL-12 p70 and RANTES and decreased expression of CCR3. In AMI a systemic inflammatory reaction predominates with enhanced expression of the early activation marker CD69 on T lymphocytes and elevated levels of IL-6 and IL-10 that suppress Th1 activation. CONCLUSION: Interferon-gamma production of activated T cells in acute coronary syndromes may, therefore, be governed by the release of specific pro- and anti-lymphocyte activating cytokines.     

A partial deficiency of interleukin-7R alpha is sufficient to abrogate T-cell development and cause severe combined immunodeficiency

Both in vitro and in vivo studies established that interleukin 7 (IL-7) is essential for differentiation of immature T cells and B cells but not natural killer (NK) cells in the mouse. In humans, although both T-cell and B-cell progenitors express the functional IL-7 receptor that consists of IL-7R alpha and the gamma common (gamma c) chain, this lymphocyte receptor system is critical for T lineage but not for B lineage development. Indeed, complete gamma c deficiency like IL-7R alpha deficiency results in the arrest of T-cell but not B-cell development (T(-)B(+) SCID). However, partial deficiency of gamma c caused by missense mutations results in a T(+)B(+) phenotype and a delay of clinical presentation. It was therefore plausible to assume that partial deficiency of IL-7R alpha, like partial gamma c deficiency may lead to a milder clinical and immunologic phenotype. A P132S mutation in the IL-7R alpha was identified in 3 patients with severe combined immunodeficiency (SCID) within an extensively consanguineous family. Substitution of proline with serine in the extracellular portion of IL-7R alpha did not affect IL-7R alpha messenger RNA (mRNA) and protein expression, but severely compromised affinity to IL-7, resulting in defective signal transduction. In response to IL-7 stimulation, Jak-3 phosphorylation was markedly reduced in both patient cells as well as in COS cells reconstituted with mutant IL-7R alpha. Surprisingly, this partial deficiency of IL-7R alpha resulted in a severe phenotype, including markedly reduced circulating T cells while sparing B-cell numbers similar to gamma c chain deficiency. However, unlike the previously reported cases, serum immunoglobulins were virtually absent. Further, unlike gamma c deficiency, NK cell numbers and function was preserved. Despite the partial deficiency, clinical presentation was indistinguishable from a complete gamma c deficiency, including severe and persistent viral and protozoal infections and failure to thrive. Unlike partial gamma c deficiency, a partial deficiency of IL-7R alpha results in an arrest of T-cell development, leading to typical severe combined immunodeficiency. This underscores the critical role of IL-7R alpha chain in the differentiation of T cells. (Blood. 2000;96:2803-2807)     

T-cell death by apoptosis in vertically human immunodeficiency virus- infected children coincides with expansion of CD8+/interleukin-2 receptor-/HLA-DR+ T cells: sign of a possible role for herpes viruses as cofactors?

One mechanism proposed to play a role in T-cell depletion in human immunodeficiency virus (HIV) infection is apoptosis (activation-induced cell death). We assessed whether apoptosis is related to activation of T cells in vivo and its possible triggers. DNA was extracted from peripheral blood mononuclear cells (PBMC) taken from 16 vertically HIV- infected children and 9 HIV-negative children born to HIV-positive mothers (controls) and tested by agarose gel electrophoresis for the presence of DNA fragments specific for apoptosis. Signs of apoptosis were found on in vitro culture of PBMC from 12 of 16 HIV-infected children, but not in PBMC from the nine controls. Eleven of the 12 HIV- infected children with apoptosis showed an elevated (> 15%) proportion of CD3+/HLA-DR+ cells. This was due to an increased proportion of CD8+/HLA-DR+ cells, as shown in 7 of 7 further tested patients. In none of the probands an increased (> 5%) proportion of IL-2 receptor expressing CD3+ cells was found. T cells undergoing apoptosis were preferentially of the CD8+ phenotype. Expansion of circulating CD8+/interleukin-2 receptor (IL-2R)-/HLA-DR+ T cells is known to occur during active infection with herpes viruses. To investigate the possible role of herpes viral coinfections for apoptosis in HIV infection, we focused on Epstein-Barr virus (EBV) as an example for a herpes virus usually acquired during childhood. In 10 of 12 patients with apoptosis, we found increased levels of EBV genome in PBMC and/or tissues, indicating active EBV replication. By contrast, no increased burden of EBV was found in the four HIV-infected patients without apoptosis or in the controls. Our data indicate that in children the occurrence of apoptosis in HIV infection is closely related to activation of CD8+ T cells. Furthermore, primoinfection with or reactivation of herpes viruses, such as EBV, may substantially contribute to such T-cell activation and the ensuing apoptosis. Additional studies are warranted to evaluate the contribution of herpes virus-triggered apoptosis to the T-cell loss leading to the acquired immunodeficiency syndrome.     

Clinical and immunologic features of pediatric patients with common variable immunodeficiency and respiratory complications

BACKGROUND: Common variable immunodeficiency (CVID) is the term used to describe a heterogeneous group of B-cell deficiency syndromes characterized by hypogammaglobulinemia, impaired antibody production, and recurrent bacterial infections. OBJECTIVES: To determine the clinical manifestations and perform an immunological analysis of pediatric CVID patients suffering from respiratory complications. METHODS: The records of 10 patients with CVID who were followed up from 1992 to 2005 (6 males and 4 females) with a median (interquartile range) age of 13.9 (10.4-19.4) years were reviewed. All patients met the standard criteria set for CVID. RESULTS: Median total serum levels of immunoglobulin (Ig) G, IgM, and IgA in mg/dL were 383.5 (239.2-574.5), 32.5 (17.0-117.0), and 12.5 (5.0-30.7), respectively. Median age at the onset of symptoms, at CVID diagnosis, and on starting intravenous Ig therapy was 4.0 (0.8-6.2), 9.4 (6.7-11.3), and 9.1 (7.0-11.6) years, respectively. Associated disorders were recurrent infections (100%), bronchiectasis (90%), and growth failure (80%), whereas malabsorption, malignant neoplasm, inflammatory bowel disease, and autoimmune disorders were less common. All bronchiectatic patients had a low percentage of B cells, with an average of 4% (range, 1%-7%). The characteristic computed tomography finding in patients with CVID was a multilobar pattern. Malignant neoplasm developed an average of 11.5 (range, 6.5-20.2) years after the diagnosis of CVID was made. CONCLUSION: Recurrent respiratory infection should be evaluated to rule out CVID. Early diagnosis and intravenous Ig replacement therapy may reduce the frequency of respiratory infection. Low levels of serum Ig and percentage of B lymphocytes at diagnosis are important parameters for identifying patients at risk of structural lung damage.     

Human ICOS deficiency abrogates the germinal center reaction and provides a monogenic model for common variable immunodeficiency

The homozygous deletion of the inducible costimulator (ICOS), an activation-induced member of the CD28 family on T cells, causes an antibody deficiency syndrome in affected humans. The identification of a total of 9 ICOS-deficient patients revealed that this monogenic disease comprises the full clinical phenotype described for common variable immunodeficiency (CVID), including recurrent bacterial infections, adult as well as childhood onset, splenomegaly, autoimmune phenomena (autoimmune neutropenia), intestinal lymphoid hyperplasia, and malignancy (carcinoma of the vulva). All patients exhibited a profound hypogammaglobulinemia and a disturbed B-cell homeostasis. The severe reduction of class-switched memory B cells resulted from poor germinal center formation in the absence of ICOS. The additional decrease of naive B cells was associated with a partial inhibition of the early B-cell development at the pre-B-I stage. T-cell homeostasis seemed not to be affected, but low IL-10 production by ICOS-deficient T cells may contribute to the disturbed germinal center reaction. Human ICOS deficiency is indistinguishable from CVID and thus serves as a monogenic model for this complex syndrome.     

Common variable immunodeficiency: 17 observations in the adult

PURPOSE: Common variable immunodeficiency (CVID) is an immune defect characterized by primary hypogammaglobulinemia. Most of the time, clinical manifestations that reveal CVID are recurrent bacterial infections, but auto-immune or granulomatous events may occur. METHODS: This retrospective study was conducted on 17 patients fulfilling the classical CVID definition. Lymphocyte activation level was evaluated in 12 patients through HLA-DR expression on lymphocytes subsets. RESULTS: This study includes 17 patients, 7 men and 10 women. The mean age at the first clinical manifestation is 23 years and the mean age at diagnosis is 39 years. Recurrent upper and lower bacterial respiratory tract infections are common to all patients. Abdominal infection due to Mycobacterium avium-intracellulare complex is found in one patient. Digestive events are dominated by chronic diarrhea caused by giardiasis, nodular lymphoid hyperplasia or villous atrophy. Seven patients developed auto-immune conditions (insulin dependent diabetes, idiopathic thrombocytopenic purpura (ITP), rheumatoid arthritis) and 7 patients have a splenomegaly. Non caseating granulomas in the spleen or in lymph node biopsies are found in 3 patients. Ten patients have a T lymphopenia, 2 have a B lymphopenia, 5 have a CD4/CD8 ratio <1, and 6 have T CD4(+) lymphocytes <400/mm(3). The study of HLA-DR expression on lymphocytes subsets shows that 7/12 patients have activated T CD4(+) and/or CD8(+) cells and these patients have auto-immune or tumoral manifestations. The other 5 patients do not have activated T lymphocytes but present with infectious events only. CONCLUSIONS: Our study allows the separation of patients with CVID according to their T lymphocytes activation level. A patient's classification is necessary to define homogeneous groups of patients to perform genetic and functional studies which will probably reveal heterogeneous molecular abnormalities.     

Increased plasma interleukin-7 level correlates with decreased CD127 and Increased CD132 extracellular expression on T cell subsets in patients with HIV-1 infection

BACKGROUND: Interleukin (IL)-7 levels are increased in patients with human immunodeficiency virus type 1 (HIV-1)-associated lymphopenia; however, the effects of this on IL-7 receptor (IL-7R) expression, disease progression, and immune reconstitution remain unclear. METHODS: Plasma IL-7 levels were measured, by enzyme-linked immunoassay, in patients with primary, chronic, or long-term nonprogressive HIV-1 infection (PHI, CHI, and LTNP, respectively) before and after 40-48 weeks of antiretroviral therapy (ART). Cell-surface expression and intracellular expression of the IL-7R components CD127 and CD132 were measured by flow cytometry. The effects of IL-7 and cycloheximide on IL-7R expression by peripheral blood mononuclear cells were examined in vitro. RESULTS: Plasma IL-7 levels were increased in both patients with PHI and those with CHI; administration of ART resulted in normalized plasma IL-7 levels in patients with PHI but not in those with CHI. Plasma IL-7 levels positively correlated with CD4(+) T cell immune reconstitution in patients with PHI. In vitro, exogenous IL-7 rapidly down-regulated cell-surface CD127 expression, but not CD132 expression, whereas subsequent reexpression required active protein synthesis. HIV-1 infection resulted in progressive decreases in the CD127(+)132(-) subset and increases in the CD127(-)132(+) subset of CD4(+) and CD8(+) T cells. Changes in CD4(+) T cell expression of IL-7R components were evident in patients with LTNP who lost viral control, and these changes preceded increases in plasma IL-7 levels. CONCLUSIONS: Perturbations in the IL-7/IL-7R system were clearly associated with disease progression but did not reliably predict immune reconstitution.