Idiopathic CD4 Lymphocytopenia: Clinical and Immunologic Characteristics and Follow-Up of 40 Patients

Idiopathic CD4 T lymphocytopenia (ICL) is a rare and severe condition with limited available data. We conducted a French multicenter study to analyze the clinical and immunologic characteristics of a cohort of patients with ICL according to the Centers for Disease Control criteria.We recruited 40 patients (24 female) of mean age 44.2 ± 12.2 (19–70) years. Patients underwent T-lymphocyte phenotyping and lymphoproliferation assay at diagnosis, and experiments related to thymic function and interferon (IFN)-γ release by natural killer (NK) cell were performed. Mean follow-up was 6.9 ± 6.7 (0.14–24.3) years. Infectious, autoimmune, and neoplastic events were recorded, as were outcomes of interleukin 2 therapy.In all, 25 patients had opportunistic infections (12 with human papillomavirus infection), 14 had autoimmune symptoms, 5 had malignancies, and 8 had mild or no symptoms. At the time of diagnosis, the mean cell counts were as follows: mean CD4 cell count: 127/mm³ (range, 4–294); mean CD8: 236/mm³ (range, 1–1293); mean CD19: 113/mm³ (range, 3–547); and mean NK cell count: 122/mm³ (range, 5–416). Most patients had deficiency in CD8, CD19, and/or NK cells. Cytotoxic function of NK cells was normal, and patients with infections had a significantly lower NK cell count than those without (p = 0.01). Patients with autoimmune manifestations had increased CD8 T-cell count. Proliferation of thymic precursors, as assessed by T-cell rearrangement excision circles, was increased. Six patients died (15%). CD4 T-cell count <150/mm³ and NK cell count <100/mm³ were predictors of death.In conclusion, ICL is a heterogeneous disorder often associated with deficiencies in CD8, CD19, and/or NK cells. Long-term prognosis may be related to initial CD4 and NK cell deficiency.Abbreviations: AIHA = autoimmune hemolytic anemia, CDC = Centers for Disease Control, CMV = cytomegalovirus, cpm = count per minute, CVID = common variable immunodeficiency, CXCR4 = C-X-C chemokine receptor type 4, HIV = human immunodeficiency virus, HLA = human leukocyte antigen, HPV = human papillomavirus, HTLV-1/2 = human T-cell lymphotropic 1/2, ICL = idiopathic CD4 T lymphocytopenia, IFN-γ = interferon-γ, IL = interleukin, JC virus = John Cunningham virus, LPA = lymphocyte proliferation assay, NK = natural killer, P = patient, PBMC = peripheral blood mononuclear cell, Pwd = pokeweed, SI = stimulation index, sj = signal joint, TREC = T-cell rearrangement excision circle     

Laryngeal involvement in rheumatoid arthritis

Laryngeal involvement was evaluated in 45 patients with moderately severe rheumatoid arthritis (RA). RA duration and severity, prior laryngeal symptoms, and abnormalities detected by concurrent indirect laryngoscopy (IL) and computerized tomography (CT) were noted and correlated with changes of basilar interstitial fibrosis (BPF) found by chest radiograph. Thirty-two percent had abnormalities detected by IL, 54% had abnormalities by CT, and 36% had BPF on chest radiographs. Comparison of these groups revealed: only two symptoms (sore throat and difficulty during inspiration) were predictive of abnormalities detected by IL; no symptoms predicted abnormalities on CT; IL and CT may show abnormalities in a large percentage of RA patients even in the absence of symptoms; IL tends to detect mucosal and gross functional abnormalities while CT detects structural lesions; BPF shown on chest radiographs in RA patients does not appear to be correlated with cricoarytenoid arthritis as defined by IL and CT.     

NKG2D blockade prevents autoimmune diabetes in NOD mice

NKG2D is an activating receptor on CD8(+) T cells and NK cells that has been implicated in immunity against tumors and microbial pathogens. Here we show that RAE-1 is present in prediabetic pancreas islets of NOD mice and that autoreactive CD8(+) T cells infiltrating the pancreas express NKG2D. Treatment with a nondepleting anti-NKG2D monoclonal antibody (mAb) during the prediabetic stage completely prevented disease by impairing the expansion and function of autoreactive CD8(+) T cells. These findings demonstrate that NKG2D is essential for disease progression and suggest a new therapeutic target for autoimmune type I diabetes.     

Case Report: Congenital Radioulnar Synostosis and Its Embryological Correlation and Functional Assessment

Congenital radioulnar synostosis(CRS) is a rare anomaly and approximately 400 cases were reported worldwide so far. CRS is the failure of the longitudinal segmentation and the persistence of the cartilaginous anlage between the radius and ulna during the seventh week of development that results in a persistent bridge of tissue. Here we are discussing on a case of 25yrs old, male patient with bilateral congenital synostosis. On the left hand the pronation and supination movements are restricted completely where as on right side 10 degree of supination and 20 degree of pronation is possible. Radiologically in our patient synostosis is classified as type II variety by Wilkie(1914)1 classification and type IV by the Cleary and Omer classification(1985). The position of forearm was not found to be related to subjective functional limitation, or employment status. Main line of treatment is surgical mainly rotational osteotomy but is rarely indicated. Our patient is not able to rotate his forearm especially on the left side still he has no functional limitation so he has refused for the operative treatment. No study has objectively compared the preoperative functional limitation of the patients with their postoperative functional improvement in order to justify surgical intervention In the authors opinion the only major factor that is to be taken into consideration of operative treatment is functional limitation to the patient.     

B7/CD28 costimulation is essential for the homeostasis of the CD4+CD25+ immunoregulatory T cells that control autoimmune diabetes

CD28/B7 costimulation has been implicated in the induction and progression of autoimmune diseases. Experimentally induced models of autoimmunity have been shown to be prevented or reduced in intensity in mice rendered deficient for CD28 costimulation. In sharp contrast, spontaneous diabetes is exacerbated in both B7-1/B7-2-deficient and CD28-deficient NOD mice. These mice present a profound decrease of the immunoregulatory CD4+CD25+ T cells, which control diabetes in prediabetic NOD mice. These cells are absent from both CD28KO and B7-1/B7-2KO mice, and the transfer of this regulatory T cell subset from control NOD animals into CD28-deficient animals can delay/prevent diabetes. The results suggest that the CD28/ B7 costimulatory pathway is essential for the development and homeostasis of regulatory T cells that control spontaneous autoimmune diseases.     

Tyrosine 201 of the cytoplasmic tail of CTLA‐4 critically affects T regulatory cell suppressive function

Cytotoxic T lymphocyte antigen‐4 (CTLA‐4) is a major negative regulatory molecule for T‐cell activation with a complex biology and function. CTLA‐4 is known to regulate homeostatic lymphoproliferation as well as tolerance induction and has been proposed to be an important effector molecule by which Treg cells suppress immunity. The immunoregulatory properties of CTLA‐4 are primarily mediated by competition with the costimulator CD28 for ligand binding but also by delivering negative signals to T cells through its cytoplasmic tail. In this study, we addressed the effect of directly mutating the amino acid residue, Tyrosine 201 (Tyr201), of the intracellular domain of CTLA‐4 in situ and its implications in T‐cell function in the context of autoimmunity. Therefore, a novel CTLA‐4 knock‐in mouse (Y201V KI) was generated, in which Tyr201 was replaced by a valine that could not be phosphorylated. Mice expressing the CTLA‐4 mutant molecule were generally healthy and did not show signs of disruption of T‐cell homeostasis under steady‐state conditions seen in CTLA‐4 deficient mice. However, T cells isolated from Y201V KI mice expressed higher levels of CTLA‐4 on the cell surface and displayed a Th2‐biased phenotype following TCR stimulation. Furthermore, Y201V KI mice developed exacerbated disease as compared to wild‐type upon antigen‐specific T‐cell activation in an in vivo model of EAE. Importantly, the Y201V mutation resulted in impaired suppressive activity of Treg cells while T effector function remained intact. These data suggest that effects associated with and mediated through Tyr201 of CTLA‐4s intracellular domain are critical for Treg‐cell function.     

Detection of chromosomes and estimation of aneuploidy in human spermatozoa using fluorescence in-situ hybridization

The development and application of fluorescence in-situ hybridization (FISH) has opened the way for comprehensive studies on numerical chromosome abnormalities in human spermatozoa. FISH can be rapidly applied to large numbers of spermatozoa and thus overcomes the major limitation of karyotyping spermatozoa after penetration of zona-free hamster oocytes. The simultaneous hybridization of two or more chromosome-specific probes to spermatozoa and subsequent detection of the bound probes using different fluorescent detection systems enables two or more chromosomes to be localized simultaneously in the same spermatozoon and provides a technique for undertaking reasonable estimates of aneuploidy. The most commonly used probes are those which bind to the centromeric region of specific chromosomes. Most studies to date have concentrated on estimating aneuploidy in spermatozoa from normospermic men, although reports are beginning to appear on aneuploidy in spermatozoa from subfertile and infertile men. Multi- probe FISH studies have generally reported disomy (hyperhaploidy) estimates of 0.05-0.2% per chromosome. There is preliminary evidence that some chromosomes such as X, Y and 21 are predisposed towards higher rates of non-disjunction during spermatogenesis. There are also suggestions of inter-donor variability in aneuploidy frequencies for specific chromosomes, although this requires confirmation in larger studies. While FISH is clearly a powerful technique that has many applications in reproductive medicine, it must also be realized that it does have limitations and the technology itself is still evolving and has yet to be fully validated on spermatozoa.      

Preliminary observations on polar body extrusion and pronuclear formation in human oocytes using time-lapse video cinematography

In this study, we have used time-lapse video cinematography to study fertilization in 50 human oocytes that had undergone intracytoplasmic sperm injection (ICSI). Time-lapse recording commenced shortly after ICSI and proceeded for 17-20 h. Oocytes were cultured in an environmental chamber which was maintained under standard culture conditions. Overall, 38 oocytes (76%) were fertilized normally, and the fertilization rate and embryo quality were not significantly different from 487 sibling oocytes cultured in a conventional incubator. Normal fertilization followed a defined course of events, although the timing of these events varied markedly between oocytes. In 35 of the 38 fertilized oocytes (92%), there were circular waves of granulation within the ooplasm which had a periodicity of 20-53 min. The sperm head decondensed during this granulation phase. The second polar body was then extruded, and this was followed by the central formation of the male pronucleus. The female pronucleus formed in the cytoplasm adjacent to the second polar body at the same time as, or slightly after, the male pronucleus, and was subsequently drawn towards the male pronucleus until the two abutted. Both pronuclei then increased in size, the nucleoli moved around within the pronuclei and some nucleoli coalesced. During pronuclear growth, the organelles contracted from the cortex towards the centre of the oocyte, leaving a clear cortical zone. The oocyte decreased in diameter from 112 to 106 microm (P < 0.0001) during the course of the observation period. The female pronucleus was significantly smaller in diameter than the male pronucleus (24.1 and 22.4 microm respectively, P = 0.008) and contained fewer nucleoli (4.2 and 7.0 respectively, P < 0.0001). After time-lapse recording, oocytes were cultured for 48 h prior to embryo transfer or cryopreservation. Embryo quality was related to fertilization events and periodicity of the cytoplasmic wave, and it was found that good quality embryos arose from oocytes that had more uniform timing from injection to pronuclear abuttal and tended to have a longer cytoplasmic wave. In conclusion, we have shown that time-lapse video cinematography is an excellent tool for studying fertilization and early embryo development, and have demonstrated that human fertilization comprises numerous complex dynamic events.      

CTLA-4 and tolerance

Potentially autoreactive T cells that escape negative selection in the thymus must be strictly controlled in the periphery to avoid autoimmune disease. The mostrobust regulatory process controlling autoreactivity is mediated by the CTLA-4-B7 pathway. The critical homeostasis mediated by CTLA-4 was proven using monoclonal antibodies and genetically disrupted CTLA-4 knockout mice that develop polyclonal lymphocyte activation and proliferation leading to massively enlarged lymph nodes and spleen and fatal multiorgan lymphocytic infiltrates. CTLA-4 ligation following T-cell activation down regulate scytokine production and cell-cycle progression, however, the proximal biochemical basis for robust T-cell regulation remains unclear. In this review, we summarize studies supporting a dynamic role for CTLA-4 at the immunological synapse leading to direct attenuation of early cell signals. A model is proposed based on these observations, which proposes that CTLA-4 may, in fact, function under some circumstances in aligand-independent manner. *** DIRECT SUPPORT *** A05Q2022 00011