[Liver injury in idiopathic CD4+T-cell lymphocytopenia].

A 48 years old patient was admitted to the Internal Medicine ward due to progressive weakness and abnormal liver function tests. During three months of hospitalization she developed opportunistic infections with Cryptococcus and Pneumocystic jiroveci pneumonia. The CD4+ T-cell lymphocyte count was very low with no evidence of infection with human immunodeficiency virus. Liver disease deteriorated with the appearance of profound jaundice and severe hepatitis. The patient's laboratory and clinical presentation were compatible with the diagnosis of idiopathic CD4 + T-cell lymphocytopenia--ICL. The authors reviewed the literature on ICL and discuss the rare hepatic presentation of this uncommon syndrome.

[Dysfunctions of the CXCL12 (SDF-1)/CXCR4 signaling axis in the WHIM syndrome and the idiopathic CD4(+) T-cell lymphocytopenia]. / Anomalies de l'axe de signalisation CXCL12 (SDF-1)/CXCR4 dans le syndrome WHIM et la lymphopénie T CD4(+) idiopathique.

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.

Involvement of CD4+CD25+ regulatory T cells in the pathogenesis of polycythaemia vera.

BACKGROUND: Regulatory T cells (T(reg)) have been shown to play an important role in the regulation of hematopoietic activity. However, there is no information about the effect of T(reg) cells in the pathogenesis of polycythaemia vera (PV). METHODS: In this study, we investigated the percentage and function of T(reg) cells in the peripheral blood of 21 PV patients and 25 healthy donors. T(reg) cells were identified and characterized as CD4+CD25+ FOXP3+ by flow cytometry. The suppressive activity of CD4+CD25+ T(reg) cells was assessed by the proliferation and cytokine secretion of the co-cultured CD4+CD25- fractions. RESULTS: The results showed that the percentage of T(reg) cells in the peripheral blood of PV patients significantly increased compared to healthy controls ((10.93 +/- 4.02)% vs (5.86 +/- 1.99)%, P < 0.05). Moreover, the mRNA and protein expression of FOXP3 was higher in CD4+CD25+ T(reg) cells. Coordinately, when co-cultured with the activated CD4+CD25- cells, the CD4+CD25+ T(reg) cells showed enhanced suppressive function in PV. Yet, the underlying mechanism for the increased frequency and function of CD4+CD25+ T(reg) cells is still to be clarified. CONCLUSION: T(reg) cells expansion might account for the abnormal T cell immunity in PV patients and thus contribute to the pathogenesis of PV.

Idiopathic CD4 lymphocytopenia and opportunistic infection--an update.

A severe CD4 T-cell depletion predisposes humans to opportunistic infections. In recent years, reports of cases of opportunistic infections caused by CD4 T-cell depletion without HIV infection have been accumulating. Such cases, termed idiopathic CD4 T lymphocytopenia (ICL), are very rare. The epidemiologic data do not suggest that the condition is caused by a transmissible agent. Unlike HIV infection, the decrease in the CD4 cell counts of patients with ICL is often slow. The clinical spectrum of ICL ranges from an asymptomatic laboratory abnormality to life-threatening opportunistic infections. However, the pathogens, clinical significance and treatment of ICL patients still await systematic research. This review summarizes the current knowledge of the poorly understood syndrome of idiopathic CD4 lymphocytopenia, providing key insights into the pathogenesis and immunologic characteristics, and suggesting approaches to enhance CD4 T-cell counts.

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.

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.

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.

Extensive ulcerative colitis and extraintestinal manifestations in a patient with HIV infection and significant CD4 T-cell lymphopenia.

We report a heterosexual patient with HIV infection and a CD4 T-cell count of 0.45 x 10(9)/L who developed mild ulcerative proctitis, sacroileitis and oligoarthiritis. While he was treated with 5-aminosalicylic enemas, the patient rapidly developed severe pancolitis. An emergency colectomy without procetectomy was performed. A few months later, he suffered recurrence of ulcerative proctitis, aggravation of arthritic pain and developed anterior uveitis. All symptoms disappeared after proctectomy. There was no evidence for opportunistic infection or Kaposi's sarcoma. Antineutrophil cytoplasmic antibodies were positive and the HLA-B27 antigen was present. CD4 counts were lower during the phases of active disease than during remission. This case demonstrates that severe ulcerative colitis can occur in the presence of moderate T-cell defects. In view of a recent report of remission of Crohn's disease under comparable circumstances, it is possible that the extent of T-cell involvement in both diseases is radically different.