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     

Relationship between the quantity of Kaposi sarcoma-associated herpesvirus (KSHV) in peripheral blood and effusion fluid samples and KSHV-associated disease

The Kaposi sarcoma-associated herpesvirus (KSHV)-DNA level was determined in samples from 71 patients with Kaposi sarcoma (KS), 28 patients with multicentric Castleman disease (MCD), and 8 patients with primary effusion lymphoma (PEL). KSHV-DNA levels were higher in patients with active KS or MCD than in those with KS or MCD in remission. Among patients with active disease, the highest KSHV-DNA levels were observed in effusion fluid samples from patients with PEL (7.2 log(10) copies/150,000 cells), followed by blood samples from patients with MCD and PEL (4.86 and 3.83 log(10) copies/150,000 cells, respectively), and the lowest levels were observed in blood samples from patients with KS (2.63 log(10) copies/150,000 cells). Determining the KSHV-DNA level may be useful in diagnosing KSHV-associated disease and for following up patients with KS when the development of MCD or PEL is suspected.     

Evidence for naive T-cell repopulation despite thymus irradiation after autologous transplantation in adults with multiple myeloma: role of ex vivo CD34+ selection and age

Immunodeficiency following autologous CD34+-purified peripheral blood stem cell (PBSC) transplantation could be related to T-cell depletion of the graft or impaired T-cell reconstitution due to thymus irradiation. Aiming to assess the role of irradiated thymus in T-cell repopulation, we studied 32 adults with multiple myeloma, randomly assigned to receive high-dose therapy including total body irradiation (TBI) followed by autologous transplantation with either unselected or CD34+-selected PBSCs. The median number of reinfused CD3+ cells was lower in the selected group (0.03 versus 14 x 10(6)/kg; P =.002). Lymphocyte subset counts were evaluated from month 3 to 24 after grafting. Naive CD4+ T cells were characterized both by phenotype and by quantification of T-cell receptor rearrangement excision circles (TRECs). The reconstitution of CD3+ and CD4+ T cells was significantly delayed in the CD34+-selected group, but eventually led to counts similar to those found in the unselected group after month 12. Mechanism of reconstitution differed, however, between both groups. Indeed, a marked increase in the naive CD62L+CD45RA+CD4+ subset was observed in the selected group, but not in the unselected group in which half of the CD45RA+CD4+ T cells appear to be CD62L-. Age was identified as an independent adverse factor for CD4+ and CD62L+CD45RA+CD4+ T-cell reconstitution. Our results provide evidence that infusing PBSCs depleted of T cells after TBI in adults delays T-cell reconstitution but accelerates thymic regeneration.     

T cell changes after combined nucleoside analogue therapy in HIV primary infection.

OBJECTIVE: To characterize the immune changes after treatment of acute HIV-1 infection with triple nucleoside analogue therapy. DESIGN: Immunological and virological parameters were monitored from day 0 to weeks 36-44 in eight patients [median CD4 cells = 451 cells/microl (range: 149-624), viral load = 4.8 log10 copies/ml (range: 6.5-3.3)] who started at time of primary HIV infection (PHI) a therapy including zidovudine (ZDV), didanosine (ddl), and lamivudine (3TC). METHODS: Lymphoid subsets were evaluated on peripheral blood lymphocytes by four-colour flow cytometry using a panel of mAbs directed against differentiation and activation markers. RESULTS: We observed a median -2.1 (range: -1; -3.3) log10 copies/ml viral load decrease and a median +158 cells/microl (range: +7 to +316) CD4 cell count increase at week 4 reaching normal CD4 cell count values of 761 CD4 cells/microl (range: 389-1153) at weeks 36-44. Virus undetectability was obtained at week 24 for all subjects. A rapid CD4 T cell amplification involved both memory and naive CD4 T cells. This was associated with a very rapid and significant decrease in activation markers [human leukocyte antigen-DR (HLA-DR), CD38] on both CD4 and CD8 T cell subsets together with a CD8+CD28+ cell increase as early as week 4. CONCLUSIONS: These results show that early therapy with nucleoside analogues can correct the immunological abnormalities observed in CD4 and CD8 T cell subsets at the time of PHI. This early kinetics in T cell recovery appears to be faster than in established disease.     

A systematic comparison of methods to measure HIV-1 specific CD8 T cells

Several methods are now available to evaluate the frequencies of virus-specific CD8 T cells but require a systematic comparison to help at choosing the best strategy for evaluation. First, we compared the ELISpot-IFNgamma assay, intracellular IFNgamma staining and HLA class I tetramer-binding assay to quantify the HIV-specific CD8 T cells. Second, we determined the frequency of recognition of HIV antigens and evaluated whether the mode of antigen presentation might influence the results: We compared HIV antigen presentation in the same ELISpot-IFNgamma assays by using recombinant vaccinia viruses (rVVs) encoding for HIV-LAI Gag, Pol, Env, Nef, Tat and Vif proteins, or a panel of 49 synthetic 8-11 amino acid length peptides tested either individually or pooled. Third, we compared the antigens recognized by memory CTL analysis using chromium release assay (CRA) on CTL lines and by effector CD8 cell analysis using ELISpot assay. Our results show that: (1) Flow cytometry and ELISpot assay measuring IFNgamma production give the same frequency of HIV-specific CD8 T cells; (2) tetramer-binding assay detects more HIV-specific CD8 T cells than other methods; (3) pools of optimal peptides and sum frequencies of individual optimal peptides give similar results in ELISpot assay; (4) ELISpot assays using peptides are more sensitive than those using rVV; and (5) CRA and ELISpot assay when using rVV provide a comparable profile of HIV antigen recognition by memory CTLs (CRA) and effector CTLs (ELISpot) in two thirds cases. These results have important implications for the choice of immunological methods to evaluate CD8 T cells responses to vaccines.     

Severe herpes virus (HSV-2) infection in two patients with myelodysplasia and undetectable NK cells and plasmacytoid dendritic cells in the blood

BACKGROUND: How the immune system contains herpes simplex virus (HSV) infections is partly understood. T cells from infected persons proliferate in response to HSV antigens in vitro and may control local relapse rather than primary infection. NK cells have been involved in the control of experimental infections. A potentially important, as yet unexplored, population of interest might be the plasmacytoid dendritic cells (PDC), which contrary to monocytes, produce very high amounts of the major antiviral molecules, type-I interferon (IFN) following interaction with HSV. OBJECTIVES: Measure type-I IFN production, PDC, and NK cells in patients with unusually severe HSV infections. STUDY DESIGN: Two female patients of 33- and 50-year-old, respectively were referred because of severe disseminated HSV2 infection and myelodysplastic marrow. One patient had leukaemia and a primary HSV2 infection whereas the other had systemic lupus erythematosus (SLE) and a chronic HSV2 infection. The following studies were performed at various time points over 18 months: analysis of the lymphocytes and PDC subsets phenotype, lymphocyte proliferation assays to recall antigens; generation of NK cells in cultures, and production of type-I IFN in serum and by HSV-infected and by sendai virus (SV)-infected blood cells. RESULTS AND CONCLUSIONS: PDC and NK cells were undetectable in the blood of both patients and NK cells could not be generated in culture at the time of ongoing infection. PBMC failed to produce IFN after infection with HSV contrasting with a normal T cell proliferation to HSV antigens in patient 1. Our observation suggests that innate immunity, through NK cells and PDC may control HSV infections, and together with IFN-producing capacity, should be investigated in patients with unusually severe HSV infections.