Low CD4 + T cell count is related to specific anti-nuclear antibodies, IFNα protein positivity and disease activity in systemic lupus erythematosus pregnancy

BACKGROUND

Lymphopenia, autoantibodies and activation of the type I interferon (IFN) system are common features in systemic lupus erythematosus (SLE). We speculate whether lymphocyte subset counts are affected by pregnancy and if they relate to autoantibody profiles and/or IFNα protein in SLE pregnancy.

METHODS

Repeated blood samples were collected during pregnancy from 80 women with SLE and 51 healthy controls (HC). Late postpartum samples were obtained from 19 of the women with SLE. Counts of CD4 + and CD8 + T cells, B cells and NK cells were measured by flow cytometry. Positivity for anti-nuclear antibodies (ANA) fine specificities (double-stranded DNA [dsDNA], Smith [Sm], ribonucleoprotein [RNP], chromatin, Sjögren's syndrome antigen A [SSA] and B [SSB]) and anti-phospholipid antibodies (cardiolipin [CL] and β2 glycoprotein I [β2GPI]) was assessed with multiplexed bead assay. IFNα protein concentration was quantified with Single molecule array (Simoa) immune assay. Clinical data were retrieved from medical records.

RESULTS

Women with SLE had lower counts of all lymphocyte subsets compared to HC throughout pregnancy, but counts did not differ during pregnancy compared to postpartum. Principal component analysis revealed that low lymphocyte subset counts differentially related to autoantibody profiles, cluster one (anti-dsDNA/anti-Sm/anti-RNP/anti-Sm/RNP/anti-chromatin), cluster two (anti-SSA/anti-SSB) and cluster three (anti-CL/anti-β2GPI), IFNα protein levels and disease activity. CD4 + T cell counts were lower in women positive to all ANA fine specificities in cluster one compared to those who were negative, and B cell numbers were lower in women positive for anti-dsDNA and anti-Sm compared to negative women. Moreover, CD4 + T cell and B cell counts were lower in women with moderate/high compared to no/low disease activity, and CD4 + T cell count was lower in IFNα protein positive relative to negative women. Finally, CD4 + T cell count was unrelated to treatment.

CONCLUSION

Lymphocyte subset counts are lower in SLE compared to healthy pregnancies, which seems to be a feature of the disease per se and not affected by pregnancy. Our results also indicate that low lymphocyte subset counts relate differentially to autoantibody profiles, IFNα protein levels and disease activity, which could be due to divergent disease pathways.

The Tumour Suppressor TMEM127 Is a Nedd4-Family E3 Ligase Adaptor Required by Salmonella SteD to Ubiquitinate and Degrade MHC Class II Molecules

The Salmonella enterica effector SteD depletes mature MHC class II (mMHCII) molecules from the surface of infected antigen-presenting cells through ubiquitination of the cytoplasmic tail of the mMHCII β chain. Here, through a genome-wide mutant screen of human antigen-presenting cells, we show that the NEDD4 family HECT E3 ubiquitin ligase WWP2 and a tumor-suppressing transmembrane protein of unknown biochemical function, TMEM127, are required for SteD-dependent ubiquitination of mMHCII. Although evidently not involved in normal regulation of mMHCII, TMEM127 was essential for SteD to suppress both mMHCII antigen presentation in mouse dendritic cells and MHCII-dependent CD4+ T cell activation. We found that TMEM127 contains a canonical PPxY motif, which was required for binding to WWP2. SteD bound to TMEM127 and enabled TMEM127 to interact with and induce ubiquitination of mature MHCII. Furthermore, SteD also underwent TMEM127- and WWP2-dependent ubiquitination, which both contributed to its degradation and augmented its activity on mMHCII.

Trichinella spiralis Infection Mitigates Collagen-Induced Arthritis via Programmed Death 1-Mediated Immunomodulation

Helminth infection induces Th2-biased immune responses and inhibitory/regulatory pathways that minimize excessive inflammation to facilitate the chronic infection of helminth in the host and in the meantime, prevent host hypersensitivity from autoimmune or atopic diseases. However, the detailed molecular mechanisms behind modulation on inflammatory diseases are yet to be clarified. Programmed death 1 (PD-1) is one of the important inhibitory receptors involved in the balance of host immune responses during chronic infection. Here, we used the murine model to examine the role of PD-1 in CD4+ T cells in the effects of Trichinella spiralis infection on collagen-induced arthritis (CIA). Mice infected with T. spiralis demonstrated higher expression of PD-1 in the spleen CD4+ T cells than those without infection. Mice infected with T. spiralis 2 weeks prior to being immunized with type II collagen displayed lower arthritis incidence and significantly attenuated pathology of CIA compared with those of uninfected mice. The therapeutic effect of T. spiralis infection on CIA was reversed by blocking PD-1 with anti-PD-1 antibody, associated with enhanced Th1/Th17 pro-inflammatory responses and reduced Th2 responses. The role of PD-1 in regulating CD4+ T cell differentiation and proliferation during T. spiralis infection was further examined in PD-1 knockout (PD-1-/-) C57BL/6 J mice. Interestingly, T. spiralis-induced alteration of attenuated Th1 and enhanced Th2/regulatory T cell differentiation in wild-type (WT) mice was effectively diminished in PD-1-/- mice characterized by recovered Th1 cytokine levels, reduced levels of Th2 and regulatory cytokines and CD4+CD25+Foxp3+ cells. Moreover, T. spiralis-induced CD4+ T cell proliferation suppression in WT mice was partially restored in PD-1-/- mice. This study introduces the first evidence that PD-1 plays a critical role in helminth infection-attenuated CIA in a mouse model by regulating the CD4+ T cell function, which may provide the new insights into the mechanisms of helminth-induced immunomodulation of host autoimmunity.

Idiopathic CD4 lymphocytopenia: Pathogenesis, etiologies, clinical presentations and treatment strategies

BACKGROUND

Idiopathic CD4 lymphocytopenia (ICL) is a rare condition characterized by an unexplained deficit of circulating CD4 T cells leading to increased risk of serious opportunistic infections. The pathogenesis, etiology, clinical presentation, and best treatment options remain unclear.

OBJECTIVE

To describe the clinical presentation, treatment strategies, and outcome of patients with ICL seen in a single referral center.

METHODS

In a retrospective study, from January 1993 to January 2014, the demographic characteristics, clinical presentation, and treatments of patients diagnosed with ICL were reviewed.

RESULTS

Twenty-four patients (14 female [58%] and 10 male [42%]) were evaluated. The mean age was 45 ± 17.6 years (range 7-76 years). Mean CD4 and CD8 T-cell counts at the time of diagnosis were 119 ± 84/mm³ (range 4-294/mm³) and 219 ± 258/mm³ (range 7-630/mm³), respectively. Seventeen patients (71%) had opportunistic infections, 4 (17%) had malignancies, and 3 (13%) had unexplained demyelinating disease and neurologic problems. Most patients had normal levels of immunoglobulins. Thirteen patients had abnormally low to absent response to phytohemagglutinin, concanavalin A, and antigens (candida and tetanus). Three patients had resolution of warts and 1 had mycobacterial lung infection on interleukin-2 with increases in CD4 count. The 11 patients on trimethoprim and sulfamethoxazole had no further hospital admissions for infections.

CONCLUSION

The pathogenesis of ICL remains unclear. Although only some patients are healthy, most patients present with opportunistic infections. There is no known standard treatment aside from prophylactic antibiotics.

Disseminated cryptococcosis in an HIV-seronegative pregnant woman with transient T-lymphocytopenia: a case report and review of the literature

We report a case of an HIV-seronegative pregnant woman with disseminated cryptococcosis, poorly controlled during gestation. Immunological studies showed T-lymphocytopenia during gestation, but rapid recovery postpartum. T-lymphocytopenia may play a role in increased susceptibility to and severity of cryptococcal infection during pregnancy.

[Dysfunctions of the CXCL12 (SDF-1)/CXCR4 signaling axis in the WHIM syndrome and the idiopathic CD4(+) T-cell lymphocytopenia]

Chemokines are small cytokine-like secreted proteins that govern migration of leukocytes to their specific niches in lymphoid organs and to inflammatory sites. They mediate their functions by binding to and activating chemokine receptors, which belong to the heptahelical G protein-coupled receptor family. The CXC chemokine Stromal cell Derived Factor-1 (SDF-1/CXCL12) is the sole natural ligand for the broadly expressed CXCR4 receptor and acts as a chemoattractant for many leukocyte subsets. The CXCL12/CXCR4 axis exerts critical activities in homeostatic processes such as organogenesis, hematopoiesis and leukocyte trafficking. Dysregulations of CXCR4 signaling and/or expression are associated with several infectious, inflammatory, autoimmune and malignant conditions. In light of recent data, we review here CXCR4 dysfunctions unveiled in two rare human immunodeficiency disorders, one characterized by a gain of CXCR4 function, the WHIM syndrome, and the other by a loss of CXCR4 function, the idiopathic CD4(+) T-cell lymphocytopenia.

Multiple immune abnormalities in a patient with idiopathic CD4+ T-lymphocytopenia

Idiopathic CD4+ T-lymphocytopenia (ICL) is a new disease entity characterized by CD4+ T-lymphocyte depletion without evidence of HIV infection. We report a 27-year-old ICL patient with a long history of multiple immune abnormalities. His CD4+ T-lymphocyte count started to decrease after generalized lymphadenopathy of an unknown cause at age 3. He satisfied the criteria for ICL at age 9, and the decreased CD4+ T-lymphocyte count persisted for more than 18 years. This is probably the first childhood-onset ICL case in which the trigger event for the development was known together with the patient's autoimmune background.

Detection of CD4(+) T-cell antibodies in a patient with idiopathic CD4 T lymphocytopenia and cryptococcal meningitis

Idiopathic CD4(+) T lymphocytopenia (ICL) is defined as a CD4(+) T-cell count <0.3 x 10(9)/l or <20% of the total T-cell count on two occasions in the absence of any immunodeficiency disorder or therapy associated with reduced CD4(+) T-cell count. Although several mechanisms of ICL have been reported, the pathophysiology is still largely unknown. This case report describes a patient who presented with cryptococcal meningitis and was subsequently discovered to meet the criteria for ICL. Flow cytometric analysis of the patient's peripheral blood mononuclear cells revealed antibodies coating a much larger proportion of his CD4(+) T cells (33.61%) than the CD4(+) T cells of normal donors (3.94 +/- 1.77%). The reasons behind the development of these autoantibodies are explored.

Mycobacterium tuberculosis ΔRD1 ΔpanCD: A safe and limited replicating mutant strain that protects immunocompetent and immunocompromised mice against experimental tuberculosis

The global epidemic of tuberculosis (TB), fueled by the growing HIV pandemic, warrants the development of a safe and effective vaccine against TB. We report the construction and characterization of an unlinked double deletion mutant of Mycobacterium tuberculosis H37Rv that deletes both the primary attenuating mutation of BCG (DeltaRD1) and two genes required for the synthesis of pantothenate (DeltapanCD). The M. tuberculosis DeltaRD1 DeltapanCD (mc(2)6030) mutant undergoes limited replication in mice, and yet is both significantly safer than BCG in immunocompromised mice and also safe in guinea pigs. Additionally, the mc(2)6030 strain does not reactivate in a mouse chemo-immunosuppression model. Importantly, long-lived protective immune responses following immunization with the mc(2)6030 strain prolong the survival of wild type mice, and CD4-deficient mice against an aerosol challenge with virulent M. tuberculosis. Given its overall safety and effectiveness, the mc(2)6030 live attenuated strain should be considered as a human vaccine candidate for protecting both healthy and HIV-infected individuals against TB.

Prevention of spontaneous arthritis by inhibiting homeostatic expansion of autoreactive CD4+ T cells in the K/BxN mouse model

OBJECTIVE

K/BxN-transgenic mice are a model of autoimmune arthritis, similar to rheumatoid arthritis. This study was undertaken to determine whether inhibition of lymphopenia-provoked homeostatic expansion can prevent spontaneous development of disease in the K/BxN model.

METHODS

To inhibit homeostatic expansion of autoreactive T cells, K/BxN mice with disease in the preclinical stage were adoptively transferred with CD4+ T cells purified from nontransgenic BxN or Thy1.1+ BxN mice. To observe the profile of proliferation of CD4+ T cells derived from the hosts, carboxyfluorescein diacetate succinimidyl ester-labeled autologous CD4+ T cells were cotransferred to K/BxN mice together with BxN CD4+ T cells. Disease onset and progression were scored, and the dynamics and phenotypes of recipient CD4+ T cells were determined by flow cytometry, before and after cell infusion.

RESULTS

During the preclinical phase of disease, K/BxN mice exhibited CD4+ T lymphopenia, which was followed by a compensatory expansion of these cells during the early clinical phase. The majority of CD4+ T cells acquired a memory phenotype (CD44(high),CD62L(low),CD25-), which is a hallmark of homeostatically expanding cells. Importantly, K/BxN mice subjected to syngeneic T cell transfer did not develop symptoms of arthritis and also possessed fewer transgenic T cell receptor-encoded Vbeta6+,CD4+ T cells. This effect was associated with decreased proliferation of recipient-derived CD4+ T cells but not with the function of CD25+ T regulatory cells present in donor cells.

CONCLUSION

These results provide the first evidence that lymphopenia-associated homeostatic proliferation of autoreactive CD4+ T cells potentiates autoimmune arthritis, and that inhibition of this process protects mice from the development of this pathologic condition.

Idiopathic CD4+ lymphocytopenia may be due to decreased bone marrow clonogenic capability

BACKGROUND

Idiopathic CD4+ lymphocytopenia is defined by a stable decrease of CD4+ T cells in the absence of any known cause of immune deficiency. The mechanisms responsible for the immunological impairment are still unknown, but a regenerative failure of hematopoietic stem/progenitor cells has been hypothesized.

METHODS

We evaluated in the bone marrow (BM) of 5 patients with idiopathic CD4+ lymphocytopenia the phenotype of BM progenitor cells, their differentiation capacity with colony-forming cells and long-term culture-initiating cell assays, in parallel with the spontaneous IL-7 production in the patient sera.

RESULTS

Compared with controls, a regenerative failure of hematopoietic stem cells has been observed, both in 'committed' and in 'uncommitted' progenitor cells, despite high IL-7 serum levels. The percentage of phenotypically primitive CD34+CD38-DR+ cells (this includes the lymphoid precursor cells) was decreased, suggesting an involvement of the more primitive BM compartment in the de novo T cell generation.

CONCLUSIONS

Despite the low number of patients, due to the low incidence of the disease, the decrease of primitive precursors sustains the possibility that diminished stem cell precursors might contribute to the development of CD4+ T cell depletion.

Idiopathic CD4+ lymphocytopenia and juvenile laryngeal papillomatosis

We report on an association of idiopathic CD4+ lymphocytopenia (ICL) and juvenile laryngeal papillomatosis (JLP) in a pediatric-aged patient. Because of a past medical history of recurrent lung infections and severe chickenpox in infancy, immunologic investigations were done at age 6 years. On several occasions, a CD4+lymphocyte count of <300 cells/mm3 was detected, supporting the diagnosis of ICL. During follow-up, both medical (interferon-alpha) and surgical treatments of JLP were only partially efficient. Our patient developed disseminated infection with Mycobacterium avium and died at 10 years of age. Human papillomavirus is an important pathogen in pediatric and adult patients with ICL. In pediatric patients with JLP who develop other unusually severe viral or opportunistic infections, immunological investigations should be considered.

Involvement of inducible costimulator in the exaggerated memory B cell and plasma cell generation in systemic lupus erythematosus

OBJECTIVE

In systemic lupus erythematosus (SLE), the increased generation of memory B cells and plasma cells leads to autoimmune hypergammaglobulinemia and destructive immunoglobulin deposits in the kidneys. We undertook this study to determine the biologic mechanism driving this overactivation of the B cell compartment, which is the central issue in SLE.

METHODS

We used flow cytometry to analyze expression of the T cell-specific inducible costimulator (ICOS) and its ligand (ICOS-L) on B cells obtained from the peripheral blood of SLE patients. We correlated ICOS-L expression with the differentiation status of the B cells using a large panel of surface antigens. In addition, SLE kidneys were analyzed by immunohistology.

RESULTS

We found an increased expression of ICOS on CD4+ as well as CD8+ T cells in SLE. At the same time, we documented a down-regulation of ICOS-L on a high proportion of peripheral blood memory B cells. Based on in vitro experiments, we inferred that this ICOS-L down-regulation on B cells was a signature of recent interaction with ICOS+ T cells in vivo. In the kidneys of SLE patients, we found clusters of B cells and plasma cells in close contact with ICOS+ T cells.

CONCLUSION

Detailed analysis of B cells with down-regulated ICOS-L suggests that ICOS is one of the forces driving the formation of memory B cells and plasma cells in SLE. Furthermore, our identification of plasma cells in areas of T cell-B cell interaction in kidneys suggests that components of a T cell-driven B cell activation process may take place in peripheral tissues in SLE.

Two Patients with Cryptococcal Meningitis and Idiopathic CD4 Lymphopenia: Defective Cytokine Production and Reversal by Recombinant Interferon- Therapy

BACKGROUND

Although Cryptococcus neoformans is a fungal pathogen that causes human disease predominantly in the immunocompromised host, severe cryptococcal infections are occasionally encountered in apparently immunocompetent individuals. Activation of cellular immunity by proinflammatory cytokines plays a central role in anticryptococcal defense.

METHODS

We describe 2 patients with severe cryptococcal meningitis who appeared to have idiopathic CD4 lymphopenia. For these patients and for 4 healthy volunteers, ex vivo stimulation of whole blood with microbial stimuli was used to investigate putative defects in cytokine production capacity.

RESULTS

Assessment of the cytokine released from the 2 patients with CD4 lymphopenia revealed a defective production of the proinflammatory cytokines interferon (IFN)- gamma and tumor necrosis factor (TNF) but not of the anti-inflammatory cytokine interleukin-10 (IL-10). One patient with disease progression despite receipt of antifungal treatment was administered immunotherapy with recombinant IFN- gamma . Administration of recombinant IFN- gamma resulted in both restoration of immunological parameters and a sustained clinical recovery.

CONCLUSIONS

Refractory meningitis may be due to defective TNF and IFN- gamma production, and IFN- gamma treatment may be useful in patients with an impaired cellular immune response and refractory cryptococcal meningitis.

Pre-seroconversion immune status predicts the rate of CD4 T cell decline following HIV infection

OBJECTIVE

To study whether immune status prior to HIV seroconversion predicts CD4 T cell decline during HIV infection.

DESIGN

Prospective cohort study including 51 injecting drug users (IDU) who were HIV negative at study entry and seroconverted for HIV during follow-up.

METHODS

Cryopreserved peripheral blood mononuclear cells obtained before HIV seroconversion were used to measure naive (CD45RO-CD27+), memory (CD45RO+CD27+), and total CD4 T cell numbers, the fraction of dividing Ki67+CD4+ T cells, and CD4 T cell receptor excision circles (TREC). The effect of pre-seroconversion immune status, as defined by these markers, on the rate of CD4 T cell decline during HIV infection was assessed using linear regression for repeated measurements.

RESULTS

IDU with low pre-seroconversion CD4 T cell TREC contents lost CD4 T cells at a significantly faster rate during HIV infection than those with a high CD4 T cell TREC content. IDU with higher pre-seroconversion CD4 T cell numbers had a significantly steeper CD4 T cell decline in the first 3 months of HIV infection, but their CD4 T cell counts remained higher throughout HIV infection. Intermediate levels of pre-seroconversion dividing Ki67+CD4+ T cells were associated with a significantly steeper CD4 cell decline than high levels. IDU with the highest pre-seroconversion drug-injecting frequencies showed slower CD4 T cell decline than those who injected less. No correlation was present between pre-seroconversion immune markers and the pre-seroconversion duration or intensity of drug use.

CONCLUSION

Among IDU, immune status prior to HIV infection as measured by TREC content affects the disease course after HIV seroconversion.

CD4+ T-lymphocytopenia--a frequent finding in anti-SSA antibody seropositive patients with primary Sjögren's syndrome

OBJECTIVE

Case reports have described an association between idiopathic CD4+ T-lymphocytopenia (ICL) and non-Hodgkin's malignant lymphoma (NHML), and both entities have an increased prevalence in patients with primary Sjögren's syndrome (SS). We investigated lymphocyte subset counts in patients with primary SS to determine if presence of different autoantibodies is associated with ICL and hence may represent an increased risk for development of NHML.

METHODS

A total of 80 patients with primary SS according to the American-European Consensus Classification Criteria (AECC) and 37 non-AECC sicca patients were studied for presence of different autoantibodies, and lymphocyte subsets were investigated by flow cytometry.

RESULTS

Absolute CD4+ T-lymphocyte counts were significantly lower among anti-SSA antibody seropositive SS patients compared to correlating seronegatives and non-AECC sicca patients (601/microl vs 956/microl and 1087/microl; p < 0.001 and p < 0.001, respectively). ICL was found in 16% of anti-SSA seropositive patients.

CONCLUSION

ICL, a proposed risk factor for development of NHML, occurs frequently and presumably exclusively in patients with primary SS who are anti-SSA antibody seropositive. These findings support that this group comprises patients at risk for development of NHML.

Toxoplasmic myositis as a presenting manifestation of idiopathic CD4 lymphocytopenia

Toxoplasma gondii encysts in skeletal muscle. Although only rarely found at muscle biopsy, this parasite has previously been regarded as a possible cause of polymyositis. We report a case of biopsy-proven toxoplasmic myositis in a non-HIV-infected patient that led to recognition of idiopathic CD4 lymphocytopenia (ICL), a rare condition typically associated with opportunistic infections. Interestingly, the CD25(+) subset that corresponds to the CD4(+) regulatory T cells controlling autoimmune processes was lacking. Steroid and antiprotozoal therapy led to recovery.

A cryptic cause of cryptococcal meningitis

Cryptococcus neoformans commonly causes opportunistic infection in immunocompromised patients, especially in patients with AIDS. The CD4+ T-lymphocyte count is measured in patients with HIV infection, because it signals an increased risk of opportunistic infection and a decline in immunological function. We report a case of cryptococcal meningitis in a patient with persistently low CD4+ cell counts without evidence of HIV infection. The patient's underlying immunocompromised state was attributed to idiopathic CD4+ T-lymphocytopenia (ICL), a recently described syndrome characterized by depletions in the CD4+ T-cell subsets without evidence of HIV infection. Immunodeficiency can exist in the absence of laboratory evidence of HIV infection, highlighting the importance of evaluating T-cell subsets in patients who present with unusual infections.

Immunodeficiency with recurrent panlymphocytopenia, impaired maturation of B lymphocytes, impaired interaction of T and B lymphocytes, and impaired integrity of epithelial tissue: a variant of idiopathic CD4+ T lymphocytopenia?

Idiopathic CD4+ T lymphocytopenia (ICL) has been defined as a cause of immunodeficiency with a variable clinical course and an unknown etiology. Here we describe a now 18-year-old boy with ICL, chronic mucocutaneous candidiasis (CMC), recurrent abscesses, and relapsing aphthous and ulcerous lesions. In addition to ICL the patient frequently showed a panlymphocytopenia. An increased percentage of gamma+delta+ T lymphocytes and IgD+ IgM+ B lymphocytes, and a decreased percentage of CD21+ B lymphocytes, were observed. In vitro assays showed normal T-cell responses to candidin and T-cell mitogens, but impaired B-cell responses to pokeweed mitogen (PWM). B-cell maturation after stimulation with Staphylococcus aureus Cowan I (SAC) and interleukin 2 (IL-2) was nearly normal. The clinical course of the patient improved substantially on administration of constant low-dose therapy with fluconazole.

Close link between CD4+ and CD8+ T cell proliferation defects in patients with human immunodeficiency virus disease and relationship to extended periods of CD4+ lymphopenia

T cell proliferation failure is commonly associated with human immunodeficiency virus (HIV) infection. By examining T cell function on a single-cell basis, we found that CD4(+) T cell proliferation failure was often accompanied by CD8(+) T cell proliferation defects in patients with HIV disease. The defects are characterized by a proportional failure and reduced efficiency of precursor T cell proliferation after stimulation. In this study, patients who historically had low levels of circulating CD4(+) T cells were most likely to demonstrate cellular proliferation failure, regardless of current CD4(+) T cell counts. In contrast, neither historical nor current plasma HIV RNA levels were predictive of proliferation failure. These results suggest that mechanisms of T cell proliferation failure are more complex than can be explained by the direct effects of HIV replication and that therapeutic intervention to avoid prolonged periods of CD4(+) lymphopenia may be desirable for the preservation of immune function in patients with HIV disease.

Idiopathic CD4+ T cell lymphocytopenia evolving to monoclonal immunoglobulins and progressive renal damage responsive to IL-2 therapy

Idiopathic CD4+ T cell lymphocytopenia was unexpectedly detected in a 33-year-old, otherwise healthy young woman with no HIV or other viral infection, autoimmune, or neoplastic disease or increased susceptibility to infection. CD4+ T cell levels were 60-140/microl over a 3.5-year period. Following an uneventful pregnancy, the patient developed anemia and interstitial nephritis associated with a plasma cell dyscrasia with a monoclonal IgA gammopathy and a shifting immunoglobulin pattern that included IgG and IgA monoclonal proteins and increased urinary light chains. Osteolytic lesions were never detected and bone marrow aspirations revealed up to 10% atypical plasma cells. Various therapies often used in treating multiple myeloma only temporarily controlled the increasing renal damage. IL-2 therapy of 600,000 to 1 million units subcutaneously daily resulted in increased CD4+ T cells to normal levels, a decrease in the gammopathy, a return of renal function, energy, and weight gain, and apparently normal health status sustained for 2 years. The findings are compatible with a potentially fatal but nonmalignant immunoregulatory disorder that can be controlled by IL-2 administration.

Lymphocyte diversity in a 9-year-old boy with idiopathic CD4+ T cell lymphocytopenia

Since CD4+ lymphocytopenia can be caused by disturbed thymic T-cell maturation, we investigated the T-cell subsets of a 9-year-old boy fulfilling the diagnostic criteria for CD4+ lymphocytopenia in a follow-up period of 4 years. We found (I) reduced CD45RA expression, (II) enhanced CD45RO expression and (III) a significant increase in gamma delta TCR-bearing T cells. An accelerated apoptosis (11%) was observed in the CD45RO+, but not CD45RA+ subset. These findings provide evidence that a disturbed thymic T-cell maturation process might play a role in the pathogenesis of CD4+ lymphocytopenia.

Retinopathy following measles, mumps, and rubella vaccination in an immuno-incompetent girl

We describe a 4-year-old girl with subnormal visual acuity due to a bilateral retinopathy. The child had a history of encephalitis following MMR vaccination. Temporary retinopathy associated with measles, mumps, and rubella (MMR) vaccination has been described. Recently an idiopathic CD4+ T lymphocytopenia in the child was diagnosed. This cellular immunodeficiency supports our hypothesis of measles retinopathy after vaccination of an immuno-deficient child.

Successful IL-2 therapy for relapsing herpes zoster infection in a patient with idiopathic CD4+ T lymphocytopenia

Idiopathic CD4+ T lymphocytopenia (ICL) has been defined by the center of disease control as a rare cause of immunodeficiency with a variable clinical course and an unknown aetiology. Here we describe a 65-year old patient with relapsing generalized herpes zoster infection due to ICL and a severe panlymphocytopenia. In vitro assays revealed an enhanced activation of CD8+ T cells and an increased sensitivity of activated CD4+ T cells for cell death. The clinical outcome was substantially improved after starting the patient on a subcutaneous therapy with IL-2.

Restriction of T-cell receptor repertoires in idiopathic CD4+ lymphocytopenia

We report that alpha/beta and gamma/delta T-cell repertoires of three patients with idiopathic CD4+ lymphocytopenia, who showed different clinical manifestations and outcomes over time, were highly restricted. The disruption of T-cell repertoires does not influence the susceptibility to infections: the first patient was unable to attain a protective response to mycobacterium, the second showed clinical improvement and the third did not develop opportunistic infections. These results indicate that idiopathic CD4+ lymphocytopenia could give rise to mono-/oligoclonal T-cell expansions, but the degree of repertoire disturbance is not indicative of the severity of disease progression.

Characterization of gammadelta T cells expressing CD158b, a killer cell inhibitory receptor, in a patient with chronic CD4(+) lymphocytopenia and disseminated Mycobacterium intracellulare infection

A population of Vdelta1(+)Vgamma9(-) gammadelta T cells that represented almost the totality (84%) of circulating lymphocytes in a patient with chronic, non-HIV-related, CD4 lymphocytopenia complicated by a disseminated Mycobacterium intracellulare infection was characterized. These gammadelta(+) T cells expressed a single killer inhibitory receptor (CD158b) and their phenotype (CD8(+)CD57(+)CD27(-)CD28(-)) indicated that, although CD45RA(+), they were not naive. However, the absence of large granular lymphocyte morphology, the impaired proliferative activity, the high susceptibility to apoptosis, and the total lack of cytotoxic ability suggested that these gammadelta cells were in a resting state. A high percentage of the cells did not harbor the CD11b integrin alpha chain and exhibited a decreased capability to bind endothelial cells. This defect might represent the mechanism whereby they remained trapped in the circulation.

Defective p56Lck activity in T cells from an adult patient with idiopathic CD4+ lymphocytopenia

Idiopathic CD4(+) lymphocytopenia (ICL) is defined by a stable loss of CD4(+) T cells in the absence of any known cause of immune deficiency. This syndrome is still of undetermined origin. It affects adult patients, some of them displaying opportunistic infections similar to HIV-infected subjects. The hypothesis that the cellular immune defect may be due to biochemical failures of the CD3-TCR pathway is investigated here in a patient associating a severe selective CD4(+) lymphocytopenia with an increased CD8(+) T cell count discovered in the course of a cryptococcal meningitidis. A 40% reduction of T cell proliferation to CD3-TCR stimulation is observed only in the CD4(+) subpopulation. The early CD3-induced protein tyrosine phosphorylations are conserved in both CD4(+) and CD8(+) subsets, and the levels of the T cell protein tyrosine kinases p56(Lck), p59(Fyn) and ZAP-70 are normal. However, we find a 50% reduction of p56(Lck) kinase activity in the patient's T cells compared to a healthy control donor. p59(Fyn) activity does not appear to be altered. Nevertheless, we do not find any genetic abnormality of p56(Lck). These results thus suggest that a defect of an unknown protein regulating p56(Lck) activity takes place in this patient's T cells. Taken together, these findings reveal p56(Lck) alteration in ICL and confirm the critical role of this kinase in the maintenance of the peripheral CD4(+) T cell subpopulation.

[CNS cryptococcosis with idiopathic CD4+ T lymphocytopenia]

A 33-year-old Japanese man, with a history of recurrent skin cryptococcosis, was admitted complaining of fever and severe headache for 3 weeks. He had no known risk factors for human immunodeficiency virus (HIV) infection. Cerebrospinal fluid examination revealed an elevated opening pressure of 32 cm H2O, cell counts of 884/mm3, a total protein value of 184 mg/dl, a glucose level of 16 mg/dl, and demonstrated a positive India ink stain for fungus. Cultures grew Cryptococcus neoformans. Hematological studies showed a persistently low CD4+ cell count (30/mm3) and a low CD4/CD8 ratio of 0.1. He has been repeatedly seronegative (ELISA and Western blot) for HIV-1 and HIV-2. He responded to fluconazole, and was given itraconazole as secondary prophylaxis because of persistent low CD4 counts. To our knowledge this is the first patient with idiopathic CD4+ T lymphocytopenia associated with CNS cryptococcosis in Japan. CD4 counts should be part of the initial work up for patients with CNS cryptococcosis.

[Cerebral intravascular lymphoma during T CD4+ idiopathic lymphopenia syndrome]

BACKGROUND

Intravascular lymphoma is a proliferation of lymphoid cells, usually B cells, in small vessels, predominantly in the nervous system and skin.

CASE REPORT

We report a case of a man with a 3-year history of lymphopenia with no detectable etiology (all viral causes were ruled out) who developed intravascular lymphoma in the cerebral vessels.

DISCUSSION

This case was particular as the patient had idiopathic CD4+ lymphopenia. It points out the probable role of immunodepression in the development of lymphomas, particularly in endovascular localizations.

Overexpression of Fas/CD95 and Fas-induced apoptosis in a patient with idiopathic CD4+ T lymphocytopenia

The mechanisms of apoptosis have become better understood, in part with the discovery of Fas/CD95. We report the case of a patient characterized by a decreased CD4+ T cell count and an overexpression of Fas/CD95 resulting in apoptosis. A 54-year-old man presented with disseminated Mycobacterium xenopi infection. Analysis showed CD4+ T lymphopenia. Tests for human immunodeficiency virus (HIV) types 1 and 2 were negative. We compared the patient with eight healthy controls and five HIV-infected patients in terms of the expression of Fas/CD95 and Fas-mediated apoptosis of peripheral T lymphocytes. The percent of CD95+ cells in lymphocytes was 98% for the patient, and the mean percent of CD95+ cells in lymphocytes +/- SD for HIV-infected patients and healthy controls was 75% +/- 16% and 36% +/- 26%, respectively. The patient had a high level of spontaneous apoptosis, and apoptotic cells were all identified as being CD4+ T cells. Monoclonal antibodies to CD95 dramatically increased apoptosis of CD4+ T cells exclusively. CD4+ T lymphopenia observed in our patient correlated with an overexpression of Fas together with spontaneous and Fas-induced apoptosis.

Hereditary CD4+ T lymphocytopenia

Two siblings suffering from mental retardation, progressive bronchiectasis, extensive warts, and persistent hepatitis B are described. The propositus also had an unusual physiognomy and non-specific colitis. Both patients had a marked decrease in the population of CD4+ helper T cells.

Idiopathic CD4+ T-lymphocytopenia in a child with disseminated cryptococcosis

We describe a Malay girl with disseminated cryptococcosis affecting the lungs, liver, lymph nodes and bones. The diagnosis was made by culture of the bone marrow. Tests of immune function showed that she was HIV-negative but the CD4 percentage was persistently low. Idiopathic CD4+ T-lymphocytopenia was diagnosed. The child died despite two courses of anti-fungal therapy.

Undefined CD4 lymphocytopenia without clinical complications. A report of two cases

A form of idiopathic CD4 lymphocytopenia (ICL) has been recently described. Its diagnostic criteria have been defined by the Centers for Disease Control (CDC), Atlanta. Associations of ICL with hepatitis C infection have been reported, while some ICL patients have presented abnormalities partly similar to those observed in common variable immunodeficiency (CVI). This paper illustrates the immunological pictures of two subjects with a CD4 deficiency confirmed in a series of peripheral blood lymphocyte subset determinations, but not associated with other cellular or humoral immunity abnormalities and accompanied by poorly significant clinical manifestations (no opportunistic infections). Patient one has been observed for a very long period. Her serological picture has been negative and she is free from hypergammaglobulinemia. HIV infection can thus be ruled out. Patient two has not required any specific treatment so far. The CDC's diagnostic criteria for ICL are not fully met in the two cases. Their pictures meet many, though not all of the CDC criteria for the diagnosis of ICL. It is to be hoped that a protracted follow-up will allow an assessment to be made of the natural history of the two cases.

Common variable immunodeficiency with CD4+ T lymphocytopenia and overproduction of soluble IL-2 receptor associated with Turner's syndrome and dorsal kyphoscoliosis

An unusual combination of common variable immunodeficiency (CVID) and Turner's syndrome in a Saudi woman aged 20 years is presented. In addition to panhypogammaglobulinaemia, the patient had CD4+ T lymphocytopenia; however, there was evidence of in vivo activation of T cells and overproduction of soluble interleukin 2 receptor in culture supernate. Mantoux test was positive, but lymphoblastic response to non-specific mitogen was impaired. Immunogenetically the patient was HLA-DR3 positive and karyotypically she was a mosaic (45XO/46XX) with ring X chromosome (46Xr(X)). The presence of severe kyphoscoliosis was possibly related to ring X chromosome. This case highlights the grave consequences of the delayed diagnosis of immunodeficiency and emphasises the heterogeneous nature of CVID.

Behçet's-like syndrome associated with idiopathic CD4+ T-lymphocytopenia, opportunistic infections, and a large population of TCR alpha beta+ CD4- CD8- T cells

Herein we report a patient with Behçet's like syndrome, idiopathic CD4+ T-lymphocytopenia, opportunistic infections, and a large polyclonal population of TCR alpha beta + CD4- CD8- T cells. Microfluorimetric analysis of peripheral blood mononuclear cells revealed CD4+ T-cell counts of 10 +/- 5/mm3. The CD3+ T cells were 99% TCR alpha beta +, of which 74 +/- 5% were CD4- CD8-. No clonal populations were detected by southern analysis for T-cell receptor V beta gene rearrangements. No evidence of human immunodeficiency virus infection was present, although nocardia, candida, pneumocystis, cytomegalovirus, and herpes infections were documented. The concomitant presence of opportunistic infections and a large population of TCR alpha beta + CD4- CD8- T cells suggests a pathogenic association and an intense immune response to microbial lipid or lipoglycan antigens presented in the context of CD1 molecules. This case demonstrates the potential for idiopathic CD4+ T-lymphocytopenia to occur in Behçet's-like syndrome with lethal consequences.

Allogeneic bone marrow transplantation can restore CD4+ T-lymphocyte count and immune function in idiopathic CD4+ T-lymphocytopenia

CD4+ T-lymphocytopenia in the absence of HIV infection is a heterogeneous disorder of unknown cause. Here we report a patient with idiopathic CD4+ T-lymphocytopenia, presenting with an opportunistic Rhodococcus equi infection. When aplastic anemia developed subsequently, allogeneic bone marrow transplantation was performed. Complete restoration of immune function was observed. We conclude that allogeneic bone marrow transplantation presents a potentially curative therapy for CD4+ T-lymphocytopenia.

Lymphocyte subset diversity in idiopathic CD4+ T lymphocytopenia

The clinical and public health importance of CD4+ T lymphocytopenia without human immunodeficiency virus infection is still unclear. We describe herein two new human immunodeficiency virus-negative patients with low numbers of peripheral CD4+ T cells and opportunistic infections (cerebral toxoplasmosis and tuberculosis plus extrapulmonary histoplasmosis). The low numbers of CD4+ CD29+ memory cells, the high percentage of gamma delta T-cell receptor cells, and the recovery of CD4+ cells after treatment were remarkable.

Antibodies against retroviral proteins and nuclear antigens in a subset of idiopathic CD4+ T lymphocytopenia patients

Idiopathic CD4+ T lymphocytopenia (ICL) is an immunodeficiency syndrome characterized by severe depletion of CD4+ T lymphocytes, but in which human immunodeficiency virus cannot be detected. Peripheral blood mononuclear cells (BPMCs) from an ICL patient were cocultured with HUT78 T-lymphoblastoid cells, and an acute cytopathic effect and formation of multinucleated cells were observed. A human intracisternal A-type retroviral particle designated HIAP-II was detected in cells surviving the acute cytopathic effect. Eight of 13 ICL patients in a blinded screen of a serological panel provided by the National Centers for Disease Control and Prevention (CDC) had serum antibodies that specifically reacted with HIAP-II associated proteins by Western immunoblotting. None of 19 control sera in the panel that were unreactive with HIV Gag proteins produced a positive result on HIAP-II immunoblots. Comparable results were obtained in a blinded screen of a second CDC serological panel. Sera from 8 of 14 ICL patients in the second serological panel were positive for antinuclear autoantibodies (ANAs) commonly observed in patients with systemic autoimmune diseases. These results suggest the possible involvement of an A-type retrovirus or autoimmunity in development of ICL in a subset of patients.

Idiopathic CD4+ lymphocytopenia and systemic vasculitis

The syndrome defined as "idiopathic CD4 lymphocytopenia' (ICL) is a rare disease of unknown aetiology, often associated with severe depression of immune defences and the occurrence of opportunistic infections. A case is reported wherein a severe immunodeficiency syndrome with persistent idiopathic CD4+ lymphopenia developed in a woman suffering from systemic microscopic polyarteritis; no signs of HIV 1/2 or HTLV I/II infection were evident. The patient died of widespread opportunistic infections. The association of ICL with vasculitis has never been reported until now. A link between the two diseases cannot be ruled out.

B non-Hodgkin's lymphoma in a haemophilia patient with idiopathic CD4+ T-lymphocytopenia

We report here a case of an HIV-uninfected, anti-hepatitis C virus (HCV) positive haemophiliac, who was transfused with blood and intermediate purity factor VIII concentrates. Since 1988, a progressive decline in the CD4+ T-cell count was recorded, and in 1993 a B-cell non-Hodgkin's lymphoma (B-NHL) was diagnosed. The morphological appearance of the tumor with features of intermediate/mantle zone lymphoma, and the absence of EBV sequences within the tumor, ruled out the occurrence of a typical "opportunistic" lymphoma. However it is possible that the blood product therapy and its infectious complications may have played a role on immune function impairment.

CD4+ T-lymphocytopenia without HIV infection: increased prevalence among patients with primary Sjögren's syndrome

OBJECTIVE

Primary Sjögren's syndrome (1 degree SS) is an autoimmune disease, usually accompanied by manifest immune hyperactivity. In some cases the disease converts to malignant neoplasia. On the other hand, there are clinical similarities to HIV infection. Since the rare phenomenon of persistent depletion of CD4+ T-lymphocytes in peripheral blood without HIV infection was recently defined as idiopathic CD4+ T-lymphocytopenia (ICL), we have used the ICL criteria to investigate the prevalence of this phenomenon among 1 degree SS patients.

METHODS

During the period 1988-94, 115 caucasian patients (10 males), mean age 57.8 (range 19-82) years, with 1 degree SS were prospectively studied. Lymphocyte subsets were investigated by means of monoclonal antibodies and flow cytometry. For the detection of HIV and HTLV antibodies, we used an enzyme immunoassay (for HIV-1 and HIV-2), Western blot techniques (HIV-1, HIV-2, HTLV-I and HTLV-II), and the polymerase chain reaction procedure (HIV-1, HTLV-I and HTLV-II). HIV antigens were tested for with the HIV-1 p-24 Ag test.

RESULTS

Six patients with 1 degree SS fulfilled the criteria for ICL. While the clinical condition of 5 of those six patients remained stable, one patient developed malignant lymphoma three years after her disease was classified as a case of ICL. The prevalence of ICL among our 115 patients with 1 degree SS was 5.2%, which is significantly higher than the rates reported for any other patient or population group. We have estimated the relative risk of ICL in 1 degree SS patients to vary from 3.4 to 6,000 (P values of 0.0001-0.025).

CONCLUSION

We suggest that subjects with ICL should be carefully examined for 1 degree SS and, if its presence is confirmed, that they should be followed with regard to the possible complications of this disease, including the development of malignant lymphoma.

CD4+ T lymphocytopenia in children: lack of evidence for a new acquired immunodeficiency syndrome agent

We investigated children with CD4+ T lymphocytopenia to determine the magnitude and public health impact of this condition and to investigate possible causes. Children < 13 years old with CD4+ T lymphocyte counts below age-adjusted cutoffs (age < 24 months, 1000 cells/microliters; age > or = 24 months, 300 cells/microliters) or < 20% on 2 separate measurements were considered to have CD4+ T lymphocytopenia. We solicited information from clinicians and public health departments on these children and their families and collected blood for immunologic and retroviral testing. We identified 18 children (10 boys; 14 African-Americans) with a median age of 10 months at their first low CD4+ T lymphocyte measurement. Three children had had opportunistic infections and two still had low CD4+ T lymphocyte counts 5 and 7 years later. Of the 11 children born to human immunodeficiency virus (HIV)-infected mothers 7 were asymptomatic. Specimens from all children were negative for HIV and human T lymphotropic virus antibodies and negative for HIV by culture or polymerase chain reaction. Among 12 families interviewed no other HIV-seronegative family or household member had illnesses suggestive of immunosuppression. We conclude that negative retroviral tests and lack of illness among their family members do not support the hypothesis that a retrovirus causes CD4+ T lymphocytopenia among these children.(ABSTRACT TRUNCATED AT 250 WORDS)

Does symptomatic primary HIV-1 infection accelerate progression to CDC stage IV disease, CD4 count below 200 x 10(6)/l, AIDS, and death from AIDS?

OBJECTIVE

To investigate the prognostic significance of symptomatic primary HIV-1 infection.

DESIGN

Prospective study of homosexual men seroconverting to HIV in 1985 and 1986. Patients were followed up at least three times yearly with clinical examinations and T cell subset determinations for an average of 7.2 years.

SETTING

Research project centred on attenders for treatment and screening for HIV at the Karolinska Institute, Stockholm.

SUBJECTS

19 patients presenting with a glandular-fever-like illness associated with seroconversion to HIV and 29 asymptomatic seroconverters.

MAIN OUTCOME MEASURES

Progression to Centers for Disease Control and Prevention stage IV disease, CD4 cell count below 200 x 10(6)/l, AIDS, and death from AIDS.

RESULTS

Symptomatic seroconverters were significantly more likely to develop Centers for Disease Control and Prevention stage IV disease (95% v 66%), CD4 cell counts below 200 x 10(6)/l (84% v 55%), and AIDS (58% v 28%) and die of AIDS (53% v 7%).

CONCLUSION

A glandular-fever-like illness associated with seroconversion to HIV-1 predicts accelerated progression to AIDS and other HIV related diseases.