The role of lymphokines in common variable hypogammaglobulinemia

Characterization of immunologic defects in patients with common variable immunodeficiency (CVID) with intestinal disease

BACKGROUND

Common variable immunodeficiency (CVID) is a heterogeneous disorder commonly presenting with recurrent sinopulmonary infections. In all, 6%-10% of CVID patients develop an inflammatory bowel disease (IBD)-like disorder, making these patients a unique population to investigate immune-mediated gastrointestinal disease. This study examined whether defects in peripheral and/or intestinal lymphocytes are involved in disruption of the intestinal mucosa in CVID patients with inflammatory intestinal diseases.

METHODS

Peripheral blood (PB) T cells from healthy controls; CD or UC; CVID; and CVID with IBD were stimulated for 48 hours with anti-CD3+CD28 or phytohemagglutinin (PHA) + phorbol 12-myristate 13-acetate (PMA); cytokine production was measured by enzyme-linked immunosorbent assay (ELISA). Cytokine expression from unstimulated lamina propria lymphocytes (LPLs) was compared by real-time polymerase chain reaction (PCR). Immunohistochemistry of mucosal biopsies was performed. Cell populations were quantified by morphometry.

RESULTS

CVID/IBD PB T cells stimulated by anti-CD3+CD28 had trends for reduced IL-2, IL-10, IFN-γ, and TNF-α compared to controls. These differences were not apparent following stimulation by PHA/PMA. Constitutive production of inflammatory cytokines by LPLs was not detected. Histologically, CVID patients had reduced/absent plasma cells with reductions in intestinal IgM and IgA. CVID patients with and without gastrointestinal (GI) disease exhibited increased CD3+ T cells, specifically CD8+, in the colon compared to normal and IBD controls, suggesting immune dysregulation.

CONCLUSIONS

Intestinal inflammation in CVID patients with IBD-like disease may be mediated by abnormal cytokine production through a T-cell receptor-mediated pathway. However, the variability observed suggests multiple, rather than singular, mechanisms are involved. Histologic features such as reduced intestinal plasma cells and lack of intestinal immunoglobulins may be useful markers in diagnosing CVID in a patient with GI disease refractory to conventional therapies.

Gastrointestinal manifestations in primary immune disorders

The gastrointestinal tract is the largest lymphoid organ in the body containing T and B lymphocytes, macrophages, and dendritic cells. Despite the fact that these cells are constantly confronted with antigen primarily in the form of food and bacteria, immune responses in the gut are tightly regulated to maintain homeostasis. Without this balance of active immunity and tolerance, mucosal inflammation may ensue, and manifest as Crohn's disease, ulcerative colitis, pernicious anemia, or celiac sprue. Therefore, it is not unreasonable that inflammatory diseases of the gut are commonly encountered in patients with primary immune deficiencies. The exact pathogenesis of gastrointestinal diseases in the setting of primary immunodeficiency remains unknown, however, both humoral and cell-mediated immunity appear to play a role in preventing intestinal inflammation. Patients presenting with atypical gastrointestinal disease and/or failure to respond to conventional therapy should be evaluated for an underlying primary immune disorder in order to initiate appropriate treatment, such as immunoglobulin or in more severe cases bone marrow transplantation, to prevent long term complications.

Common variable immune deficiency and autoimmunity

Common variable immunodeficiency (CVID) is a heterogeneous syndrome characterized by various degrees of hypogammaglobulinemia. Similar to many immunodeficiency disorders, autoimmunity is common with an association with autoimmune cytopenias, a sarcoidosis-like disorder and inflammatory bowel disease. Recent efforts have characterized selective immunological defects and genetic associations in CVID and demonstrate an increased tendency towards loss of tolerance. The mainstay of treatment of autoimmune disease in such patients is often high dose IVIG and corticosteroids, although other therapies, including TNF-alpha antagonists, have been reported. While the etiology of increased autoimmunity in CVID remains elusive, certain genetic predispositions in combination with repeated antigen exposure and overall immune dysregulation inherent in CVID likely play a significant role.

Autoimmune manifestations in common variable immunodeficiency

Common variable immunodeficiency (CVID) is a disorder characterized by decreased serum immunoglobulin concentrations and increased incidence of recurrent infections. Interestingly 20-25% of patients with CVID develop clinical features suggestive of an autoimmune disease. Although this association is well established, the immunodeficiency background of CVID patients manifesting autoimmune disorders is often overlooked. This study describes three CVID patients displaying a variety of autoimmune manifestations. The pathophysiologic mechanisms of autoimmunity in CVID are also reviewed.

Lymphomas of mucosal-associated lymphoid tissue in common variable immunodeficiency

Common variable immunodeficiency (CVID) is a primary immunodeficiency disease characterized by low serum immunoglobulins IgG, IgA, and usually IgM. The central immune deficiency is impaired secretion of immunoglobulins and lack of antibody production; however, T cell dysfunction and a variety of inflammatory complications suggest global immune dysregulation. A number of reports have documented the association of primary immunodeficiency diseases with the development of non-Hodgkin's lymphoma (NHL). In CVID, the risk has been estimated to lie between 1.4% and 7%. As for NHL arising in other immunodeficiency states, the lymphomas in CVID are extranodal and are usually B cell in type. Of 22 B cell lymphomas that have appeared over a period of 25 years in a cohort of subjects with CVID, five lymphomas, appearing in more recently studied subjects, that arose in mucosal sites would be classified as mucosa-associated lymphoid tissue (MALT) lymphomas. MALT lymphomas are low-grade B cell lymphomas that result from a proliferation of neoplastic marginal-zone related cells of lymphoid tissue and tend to occur in organs that have acquired lymphoid tissue due to long-term infectious or autoimmune stimulation. Lymphomas of this kind have not been described in patients with congenital immunodeficiency, although chronic mucosal antigen stimulation is an integral part of these immune deficiency states.

Common variable immunodeficiency treated with a recombinant human IgG, tumour necrosis factor-alpha receptor fusion protein

Common variable immunodeficiency (CVI) is characterized by a failure in B-cell differentiation and impaired immunoglobulin secretion, but with a variable clinical presentation, including the development of sarcoidal granulomas and autoimmune diseases, as well as an increased incidence of malignancies. We present a 21-year-old white man who carried a diagnosis of juvenile rheumatoid arthritis and presented 6 years later with scarring alopecia showing sarcoidal granulomas. Further work confirmed the diagnosis of CVI, and with increasing systemic symptoms, it was elected to treat the patient with a tumour necrosis factor (TNF)-alpha antagonist, a TNF-alpha receptor IgG1 fusion protein. The patient showed improvement in his systemic symptoms and some hair regrowth after 3 months of therapy, and continued improvement in his systemic disease with only mild scalp hair thinning in the areas of prior involvement after almost 1 year of therapy. CVI and sarcoid may have overlapping clinical and immunological findings. Previous therapies for CVI, including intravenous immunoglobulin, have not altered the mortality of the disease. TNF-alpha is a primary cytokine and is elevated in CVI, and specific inhibition of TNF-alpha in this patient was effective in moderating his disease, including his skin disease.

Common variable immunodeficiency (CVID) and inclusion body myositis (IBM)

A case of a 38-year old man with a common variable immunodeficiency syndrome (CVID) is demonstrated who suffered at the same time from a histologically proven inclusion body myositis (IBM). The myositis did not resolve after institution of regular intravenous IgG infusions. This case demonstrates a very long lasting benign course of IBM. The occurrence with CVID may be a clinical hint for a viral pathogenesis of IBM. So far only two similar cases are reported in the literature.

Common variable immunodeficiency: clinical and immunological features of 248 patients

Common variable immunodeficiency (CVI) is a primary immunodeficiency disease characterized by reduced serum immunoglobulins and heterogeneous clinical features. In these studies we describe the clinical and immunological status of 248 consecutively referred CVI patients of age range 3-79 years who have been followed for a period of 1-25 years. The median age at the time of onset of symptoms was 23 years for males and 28 years for females; the mean age at which the diagnosis of CVI was made was 29 years for males and 33 years for females. Forty percent of patients had impaired T cell proliferation to one or more mitogens; lymphocyte transformation to mitogens was directly related to the level of the serum IgG. Females at all ages had higher levels of serum IgM than males. Survival 20 years after diagnosis of CVI was 64% for males and 67% for females, compared to the expected 92% population survival for males and 94% for females. Parameters associated with mortality in this period were lower levels of serum IgG, poorer T cell responses to phytohemagglutinin, and, particularly, a lower percentage of peripheral B cells (P < 0.006).

IL-10 production in common variable immunodeficiency

Common variable immunodeficiency, (CVI) is a heterogeneous primary immunodeficiency disease in which there are T and B cell defects. Since IL-10 in conjunction with anti-CD40 promotes secretion of IgG, IgA, and IgM by CVI B cells, these studies were performed to investigate IL-10 production in CVI. Mitogen or anti-CD3 stimulated CVI peripheral blood mononuclear cells, or isolated T cells produced an insignificant amount of IL-10 over background levels. CVI monocyte IL-10 production was substantial and greater than that of normal controls. Anti-IL-10-neutralizing antibody strongly enhanced CVI T cell proliferative responses to PHA, but only to an insignificant extent, soluble antigens. IL-2 plus anti-IL-10 enhanced CVI proliferative responses to antigens significantly more over baseline than for cells of similarly tested normal controls. These data suggest that CVI T cell secretion of IL-10 is deficient, but that monocyte-derived IL-10, plus a relative lack of IL-2 production, could contribute to the defects of cell proliferation in this disorder.

A double-blind, placebo-controlled, crossover therapy study with natural human IL-2 (nhuIL-2) in combination with regular intravenous gammaglobulin (IVIG) infusions in 10 patients with common variable immunodeficiency (CVID)

Ten CVID patients with defective IL-2 synthesis in vitro were treated with nhuIL-2 in a placebo-controlled, double blind, crossover therapy study during a period of 12 months. No severe side-effects of nhuIL-2 were recorded. Marginal serum nhuIL-2 levels were measurable in individual patients only during the therapy phase. Serum levels of soluble IL-2 receptors were unaffected by the therapy. nhuIL-2 and placebo groups did not differ significantly with respect to requirement of IVIG substitutions which were performed whenever serum IgG levels dropped below 5 g/l: a total of 53 IVIG infusions (corresponding to 17.6 g IgG/month per patient) was necessary during the placebo phase, and 48 infusions (16.4 g IgG/month per patient) during the nhuIL-2 treatment phase. Thus, nhuIL-2 therapy was ineffective in improving spontaneous IgG synthesis in vivo. Nevertheless, the group of patients receiving nhuIL-2 during the first 6 months of the study exhibited a significant reduction of severe infections (n = 25) during the following 6 months of placebo treatment (n = 7) (P<0.045). The infection score dropped in this group from 181 to 23 (P<0.015). Patients of the second group receiving first placebo and then nhuIL-2 did not experience a significant difference in number and score of infectious episodes: 25 infections were recorded during the first 6 months and 24 during the following 6 months. We suppose that nhuIL-2 therapy of CVID patients reduces susceptibility to severe infections, possibly via the induction of a specific antibody response, which is effective at the earliest 6 months after initiating nhuIL-2 therapy.

Common variable immunodeficiency (CVID) and MxA-protein expression in blood leucocytes

The underlying immunopathogenic mechanism of CVID has been suspected to involve a chronic viral infection or an autoimmune condition. However, formal proof of viral infection is lacking. Measurement of MxA-protein in leucocyte lysates is a sensitive test for evaluating the activation of the host's interferon system. Both viral infections and autoimmune diseases such as systemic lupus erythematosus (SLE) strongly induce MxA-protein in peripheral leucocytes. We therefore examined 15 patients with longlasting hypogammaglobulinaemia for MxA-protein induction in vivo: 13 patients suffered from CVID, one from hyper-IgM syndrome, and one patient had chronic B lymphocytic leukaemia associated with immunoglobulin deficiency and chronic papilloma virus infection (condylomata accuminata). Only the latter patient exhibited a strong MxA-protein expression; two CVID patients were borderline positive, and the remaining 12 patients including the hyper-IgM syndrome were MxA-protein-negative. There was no relationship between MxA expression and low CD4/CD8 ratios or increased CD8/CD57+ T cell counts, although both conditions are often observed in CVID as well as in chronic viral infections. When exposed in vitro to interferon-alpha (IFN-alpha), peripheral blood leucocytes of four MxA-negative patients were capable of producing normal amounts of MxA-protein. Taken together, these results argue against a viral or autoimmune pathogenesis of CVID.

Immunologic effects of low-dose polyethylene glycol-conjugated recombinant human interleukin-2 in common variable immunodeficiency

Children or adults with the primary immunodeficiency disease, common variable immunodeficiency (CVI), have abnormally low levels of at least two of the three serum Ig isotypes. Although there appear to be intrinsic B cell defects, many have poor T cell proliferation and deficient secretion of IL-2, IL-4, IL-5 interferon-gamma, and B cell differentiation factor. Because the addition of various T cell factors can enhance Ig secretion in vitro in CVI, we have hypothesized that the B cells in this disease may be defective because they lack appropriate investigating the in vivo effects of recombinant IL-2 using a new biologic, polyethylene glycol-conjugated recombinant IL-2 (PEG-IL-2). In these studies, CVI patients were treated with weekly subcutaneous injections of PEG-IL-2. After 12 weeks, each patient had enhanced T cell proliferation, normal IL-2 production, boosted BCDF secretion, and B cells responsive to differentiation signals. During PEG-IL-2 treatment, four of five patients produced detectable serum antibody to keyhole limpet hemocyanin. These data suggest that CVI, which has the phenotype of B cell deficiency, may be caused by a lack of appropriate T cell signals for B cell maturation.

Defective CD2 T cell pathway activation in common variable immunodeficiency (CVID)

Clonal T cell expansion requires simultaneous activation of the TCR and secondary signals, e.g. CD2, CD4, CD28. Interference of CD2/CD58 interaction with MoAbs abrogates the primary immune response and antibody production. Given this functional importance of CD2/CD58 interaction for the generation of specific immune responses, we demonstrate for the first time a defective CD2 pathway activation in patients with CVID (seven children and four adults). The costimulatory effect of monocytes upon CD2-triggered proliferation was significantly impaired in CVID patients: 4.080 ct/min versus 20.769 ct/min in controls (P < 0.05). Second, IL-1, which is a strong comitogenic factor for activation via CD2 in normal T cells, showed a defective amplifier function of the CD2 pathway in most patients (median 1.714 ct/min in patients versus 17.521 ct/min in controls; P < 0.05). In addition, by using a mitogenic combination of CD2 plus CD45 MoAb, median proliferation of T cells was severely depressed in patients: 10.577 ct/min versus 34.685 ct/min in controls (P = 0.005). In conclusion, the marked dysfunction seen in responsiveness to phytohaemagglutinin (PHA) (median 24.594 ct/min in patients versus 52.229 ct/min in controls; P < 0.001) and after CD2 triggering, together with the unaffected response to TCR-CD3, suggest that the T cell deficiency in CVID is in part due to deficiencies in the CD2 pathway. Since direct activation of protein kinase C(PKC) by phorbol ester restores defective T cell responses to normal, our results suggest that an early signal-transducing defect might exist at a step proximal to PKC activation in patients with CVID.

"NK-like" T cytotoxicity against B lymphocytes in a hypogammaglobulinemic patient

Physiologically, cells with NK activity appear to exert a negative control on immunoglobulin production. The clinical association of large granular lymphocyte (LGL) proliferation with hypogammaglobulinemia suggests that these functional NK cells could also be involved in pathological situations. We studied in vitro lymphocyte functions in a patient presenting LGL proliferation associated with hypogammaglobulinemia. The CD3+ CD8+ CD57+ CD16- phenotype lymphocytes expressed a high NK type cytotoxicity towards K562 targets, suggesting that they may be considered as "NK-like" T cells. We cultured the patient peripheral blood mononuclear cells (PBMC) with control subject PBMC and with PBMC from two other subjects with B chronic lymphocytic leukemia (B-CLL) of the CD20+ CD21- CD10- phenotype. Patient PBMC exhibited a lytic activity on control PBMC and on the B lymphocytes of one of the two B- CLL but only in the presence of PWM. This activity was not exerted by the culture supernatant and required a cell-to-cell contact. We suggest that the hypogammaglobulinemia observed in this patient may be related to a cytotoxic effect exerted on B lymphocytes by a CD3+ CD8+ CD57+ CD16- LGL proliferation.

B cells from subjects with CVI can be driven to Ig production in response to CD40 stimulation

The majority of patients with common variable immunodeficiency (CVI) have low to normal numbers of membrane Ig-bearing B cells; yet these cells fail to differentiate in vivo resulting in hypogammaglobulinemia. We have suggested that the differentiation failure of CVI B cells is related to a failure to respond appropriately to signals involved in terminal B cell differentiation as most CVI subjects' cells undergo activation and proliferation normally. Whether this failure relates to a direct "intrinsic" defect in the B cells or is secondary to a lack of appropriate T cell or other influences in vivo is uncertain. We have previously reported that the majority of patients with CVI have elevated circulating levels of IL-6. We now show that the IL-6 produced by these patients is functionally normal. Additionally, the display of IL-6 receptors on in vitro stimulated CVI B cells is normal. However, we found that the patients' cells do not make IgE in response to an IL-6/T-cell-dependent differentiation pathway employing exogenous interleukin-4 (IL-4). The failure to respond in the IL-6-dependent system could not be overcome by exogenous IL-6 or varying doses of IL-4. In contrast, when stimulated by CD40 plus IL-4 in a differentiation pathway that does not require IL-6, B cells from CVI patients were stimulated to produce IgE. These findings, along with our earlier data showing that 13-cis-retinoic acid can drive maturation in CVI patients, strengthen the concept that B cells in patients with CVI have the potential for terminal differentiation but do not appear to achieve this in vitro or in vivo through a polyclonal Ig differentiation pathway that employs IL-6 as one of its maturation signals.

LFA-1-dependent OKT3-driven T cell clusters in common variable immunodeficiency

The triggering of the TCR/CD3 complex by anti-CD3 (OKT3) antibody leads to the formation of T cell clusters. In cultures of T lymphocytes from most normal individuals, the peak of cluster formation occurs at 24 h, but with cells from patients with common variable immunodeficiency (CVI) it was seen earlier at 4-9 h; in addition, the clusters were larger than normal, particularly at 9 h. Cluster formation by CVI and normal cells was dependent on temperature and divalent cations, but did not require Fc receptors. Since OKT3 clustering is known to be dependent on the LFA-1/ICAM-1 adhesion system, the effect of monoclonal antibodies directed against these molecules was tested. A potent inhibitor was the antibody against the common beta chain of the integrin family (CD18), but of four MoAbs against the alpha chains (CD11), three inhibited and one stimulated T cell aggregate formation. Increased expression of LFA-1 or ICAM-1 on CVI patients' T cells could not be demonstrated. The accelerated clustering was therefore probably due to an increase in the proportion of cells carrying the activated form of LFA-1. The formation of large numbers of homotypic lymphocyte clusters might reduce the effective interaction between B and T cells, thus contributing to the depression of immunoglobulin synthesis observed in this disease.

Improved in vitro antigen-specific antibody synthesis in two patients with common variable immunodeficiency taking an oral cyclooxygenase and lipoxygenase inhibitor (ketoprofen)

In the process of performing a previously published study examining B cell function in 16 patients with common variable immunodeficiency (CVI)(J Allergy Clin Immunol 1991; 87:1138-49), we noted improved in vitro antibody (Ab) synthesis in a patient, H. B., while he was taking a cyclooxygenase and lipoxygenase inhibitor, ketoprofen. Addition of ketoprofen in vitro to B cells from patients with CVI resulted in improved proliferation and differentiation in four of five additional patients with CVI studied. One patient, besides H. B., M. K. B., whose B cells secreted increased amounts of antigen (Ag)-specific Ab in response to in vitro ketoprofen, underwent a trial of oral ketoprofen M. K. B., like H. B., demonstrated improved in vitro Ag-specific Ab production while she was taking oral ketoprofen. No increase in serum Ab levels was noted in either patient taking ketoprofen, but both patients remained infection free during the time of their ketoprofen trials (H. B., 9 months, and M. K. B., 36 months). No improvement in in vitro Ag-specific Ab synthesis was noted when H. B. and M. K. B. took oral cyclooxygenase inhibitors (naproxen or ibuprofen). Thus, additional study is warranted to examine the role of lipoxygenase products of arachidonic acid in the B cell dysfunction of CVI.

Abnormal response to a human B cell growth factor in patients with common variable immunodeficiency (CVI)

Patients with common variable immunodeficiency (CVI) generally fail to produce antigen-specific IgG. We have identified a lymphokine called high molecular weight B cell growth factor (HMW BCGF) that expands an IgG-producing subpopulation of B cells. The B cells from 15 of 16 patients with CVI evaluated in this study failed to proliferate to HMW BCGF, although they proliferated normally to another BCGF, low molecular weight BCGF (LMW BCGF). Nevertheless, 11 patients had more than normal numbers of B cells expressing HMW BCGF receptors. The HMW BCGF receptors on the B cells of three patients with CVI studied were the same molecular weight as the normal HMW BCGF receptor. Examination of B cells from four patients with CVI for intracellular signals produced in normal B cells after stimulation with HMW BCGF revealed that B cells from patients with CVI failed to developed significant increases in cyclic adenosine monophosphate or phosphoinositides after HMW BCGF stimulation. However, cytoplasmic phosphoinositides in the B cells from all four patients with CVI were already increased above what is observed in normal B cells before stimulation with HMW BCGF (either freshly isolated or Staphylococcus aureus Cowan I-activated B cell). Thus, the failure of B cells from patients with CVI to respond to HMW BCGF may be related to their abnormal activation in vivo. Since HMW BCGF expands a subpopulation of memory B cells, the inability of CVI B cells to respond to HMW BCGF may contribute to their abnormal secondary responses to antigens.

Abnormalities associated with the bursal microenvironment in spontaneous dysgammaglobulinemia of UCD line 140 chickens

UCD line 140 chickens have been previously reported to develop a syndrome of spontaneous 7s immunoglobulin deficiency and the presence of autoantibodies. Earlier studies demonstrated that these inbred birds have normal peripheral blood T and B cell numbers; they also respond normally to allogeneic stimulation. Although the 7s immunodeficiency does not manifest itself until several months of age, line 140 birds have a premature degeneration of bursa. Because of the recent development of monoclonal reagents specific for bursal elements, including surface epithelium, basement membrane associated epithelium, follicle associated epithelium, and lymphoid subpopulations, we have examined line 140 and control birds for the expression of bursal epithelial cell antigens. Line 140 birds, in contrast to control chickens, have a dramatic early alteration in the expression of an epithelial cell marker in the bursa, thymus, and intestine. Moreover, to further address this issue, we transplanted bursa from 10-day embryos onto the chorioallantoic membrane, a privileged site. Bursae from control birds became abnormal when transplanted onto line 140 CAM; they remained normal when transplanted among several control chicken lines. In contrast, line 140 bursa remained abnormal independent of the transplant procedure. Due to the marked bursal abnormality observed specific to the dysgammaglobulinemia chicken line, we propose that the microenvironmental features of line 140 bursa may predispose these birds to the development of humoral immunodeficiency and autoantibodies.

Hypogammaglobulinemia in McArdle myopathy (glycogenosis type V)

Glycogenosis type V (McArdle) was the first myopathy to be enzymatically defined myopathy and has been found in approximately 120 patients. It is characterized by a myophosphorylase defect. In 2 patients with completely missing phosphorylase activity, muscle fiber necrosis and creatinine kinase elevation, we found reproducibly low gammaglobulins and low immunoglobulin-G. Compared with 124 nonmyopathic control patients with hypogammaglobulinemia, we did not find any established cause for low gammaglobulins in either case of McArdle disease. Myopathies with selected laboratory features or histopathology in common did not show changes in gammaglobulins or immunoglobulins. Unaffected family members had normal gamma-globulins and immunoglobulins. Therefore, gammaglobulins indicate an immunologic involvement in phosphorylase deficiency, and a potential for genomic co-localization.

Classification of patients with common variable immunodeficiency by B cell secretion of IgM and IgG in response to anti-IgM and interleukin-2

We have classified patients with common variable immunodeficiency (CVI) on the basis of the ability of their B cells to respond to anti-IgM and interleukin (IL)-2 in vitro. Group A had cells unable to secrete IgM or IgG, Group B secreted IgM alone, and Group C secreted both IgM and IgG. A separate small group of patients lacked peripheral B cells. Where Ig secretion was present with anti-IgM and IL-2, EBV increased it, but where it was absent, EBV only induced IgM secretion in two out of eight Group A patients and IgG in one out of five Group B patients. These classifications are related to the sex of the patient and may represent different loci of the block in B-cell differentiation in CVI.