
Real World Analysis on Lymphocyte Reconstitution After Lymphopenia in Participants Treated by Tecfidera...
Multiple SclerosisMultiple Sclerosis1 moreThe primary objective of the study is to describe absolute lymphocyte count (ALC) reconstitution after Dimethyl fumarate (DMF) discontinuation, in Relapsing-Remitting Multiple Sclerosis (RRMS) participants with lymphopenia. The secondary objectives of the study are characterization of lymphopenia in overall population; characterization of lymphopenia in participant with DMF discontinuation ; description of the evolution of ALC during DMF treatment; description of the time to reach a discontinuation of DMF treatment; exploration of the time to reach clinical outcomes (Expanded Disability Status Scale [EDSS] and relapse) according to lymphopenia; description of the event rate of the serious or opportunistic infections in overall population from DMF initiation and according to DMF discontinuation and lymphopenia; description of the event rate of serious and opportunistic infections in overall population from DMF initiation and according to lymphopenia; estimation of the associations between the baseline demographic and clinical characteristics and the risk to reach a lymphopenia; estimation of the associations between the baseline demographics and clinical characteristics and the risk to reach an ALC reconstitution after DMF discontinuation in participants with lymphopenia; and investigation of the changes of absolute cluster of differentiation 4 (CD4) and cluster of differentiation 8 (CD8) count in overall population on DMF if available.

Idiopathic CD4 Lymphocytopenia
Idiopathic CD4 LymphocytopeniaDefinition: Idiopathic CD4+ T lymphocytopenia (ICL) is an immune deficiency first described in 1992 and characterized by the US Centers for Disease Control (CDC) as absolute CD4+ T-lymphocyte count < 300/mm3 or < 20% of total T cells on more than one cell count; no evidence of infection with HIV-1/2 or human T-cell lymphotropic 1/2 (HTLV-1/2); and lack of a defined immune-deficiency disease or therapy for lymphocytopenia. Epidemiologic, clinical and immunological characteristics of the syndrome were described in 1993 and ICL is now considered a heterogeneous syndrome not caused by an infectious agent. Patients with ICL may show opportunistic infections such as disseminated Cryptococcus neoformans infection, Pneumocystis jiroveci pneumonia and John Cunningham (JC) virus infection as a result of profound cell-mediated immune-response deficiency. Few studies have focused on the pathophysiology of ICL. CD4+ T-lymphocyte phenotyping revealed increased CD95 expression that could be responsible for excess apoptosis leading to lymphocytopenia. Moreover, the membrane expression of C-X-C chemokine receptor type 4 (CXCR4) was found impaired in T lymphocytes with ICL, and CXCR4 trafficking was improved with interleukin 2 (IL-2) treatment in some patients. Recently, mutations in nunc119, MAGT1 and Rag were found associated with CD4+ T lymphocytopenia. In a prospective study of 39 patients, CD8+ T lymphocytopenia (<180/mm3) and degree of CD4+ T-cell activation measured by human leukocyte antigen DR (HLA-DR) expression was found associated with poor prognosis. 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. Larger studies are needed to better identify the patients who might benefit from IL-2 therapy. This is why the investigators conduct the Lympho-4 study, in which the investigators plan to include 200 patients with a suspected/proven diagnosis of ICL.

Newborn Screening for Severe Combined Immunodeficiency (SCID) in a High-Risk Population
Severe Combined ImmunodeficiencyT Cell LymphocytopeniaThe goal of the proposed research is to establish the validity of a newborn screening method for severe combined immunodeficiency (SCID). The assay to be used is developed on the basis of PCR quantification of T-cell receptor excision circles (TRECs) that is absent in SCID patients, thus correlating with the disease

Etiology of Lymphopenia in Covid19 Infection
LymphopeniaStudy of the cause of lymphopenia in Covid19 viral infection will be done in 3 cohorts. First cohort will be patients asymptomatic or with mild symptoms. Second cohort will be patients with severe illness and admitted to ICU. Third cohort will be patients critically ill and on artificial ventilation.

Assessment of Postoperative Lymphopenia as Risk Factor for Postoperative Infections
Cancer of the Digestive SystemThoracic DiseasesPostoperative infections are one of the most common complications in thoracic and digestive cancer surgery. Former studies have demonstrated that inflammatory response is altered during peri-operative period causing lymphopenia. It has been suggested that lymphopenia may contribute to postoperative infection. To date, no one has proved it in a multivariate analysis. The aim of this study is to determine if lymphopenia is associated with postoperative infections in thoracic and digestive cancer surgery.

Lymphocyte Count as a Sign of Immunoparalysis and Its Correlation With Nutritional Status in Septic...
LymphopeniaParticipants were classified as normal or malnourished according to anthropometric measures. Serum albumin and zinc were recovered on the 1st and 7th days of hospitalization. Lymphocyte count was also recorded on the 1st and 7th days.

Risk Factors for Low Lymphocyte Count in Patients With Type 2 Diabetes
Diabetes MellitusType 2The purpose of this study is to identify risk factors for low lymphocyte count among patients with type 2 diabetes who are treated with oral antidiabetic drugs.

Regional Differences in Human Immunodeficiency Virus (HIV) Testing
HIV SeropositivityCD4+ T LymphocytopeniaThis retrospective observational study aims at the examination of regional differences in the procedure of referral for serological HIV testing between eastern (new) and western (old) German federal states.