lymphocytopenia

In some cases, lymphocytopenia can be further classified according to which kind of lymphocytes are reduced. If all three kinds of lymphocytes are suppressed, then the term is used without further qualification.

• In T lymphocytopenia, there are too few T lymphocytes, but normal numbers of other lymphocytes. It causes, and manifests as, a T cell deficiency. This is usually caused by HIV infection (resulting in AIDS), but may be Idiopathic CD4+ lymphocytopenia (ICL), which is a very rare heterogeneous disorder defined by CD4+ T-cell counts below 300 cells/μL in the absence of any known immune deficiency condition, such as human immunodeficiency virus (HIV) infection or chemotherapy.{{cite journal | vauthors = Malaspina A, Moir S, Chaitt DG, Rehm CA, Kottilil S, Falloon J, Fauci AS | title = Idiopathic CD4+ T lymphocytopenia is associated with increases in immature/transitional B cells and serum levels of IL-7 | journal = Blood | volume = 109 | issue = 5 | pages = 2086–8 | date = March 2007 | pmid = 17053062 | pmc = 1801046 | doi = 10.1182/blood-2006-06-031385 }}
• In B lymphocytopenia, there are too few B lymphocytes, but possibly normal numbers of other lymphocytes. It causes, and manifests as, a humoral immune deficiency. This is usually caused by medications that suppress the immune system.{{citation needed|date=July 2020}}
• In NK lymphocytopenia, there are too few natural killer cells, but normal numbers of other lymphocytes. This is very rare.{{citation needed|date=July 2020}}

Lymphocytopenia is commonly caused by a recent infection, such as COVID-19.{{cite journal |vauthors=Guo Z, Zhang Z, Prajapati M, Li Y |title=Lymphopenia Caused by Virus Infections and the Mechanisms Beyond |journal=Viruses |volume=13 |issue=9 |pages=1876 |date=September 2021 |pmid=34578457 |pmc=8473169 |doi=10.3390/v13091876 |doi-access=free}}

Lymphocytopenia, but not idiopathic CD4+ lymphocytopenia, is associated with corticosteroid use, infections with HIV and other viral, bacterial, and fungal agents, malnutrition, systemic lupus erythematosus,{{cite journal | vauthors = Ng WL, Chu CM, Wu AK, Cheng VC, Yuen KY | title = Lymphopenia at presentation is associated with increased risk of infections in patients with systemic lupus erythematosus | journal = QJM | volume = 99 | issue = 1 | pages = 37–47 | date = January 2006 | pmid = 16371405 | doi = 10.1093/qjmed/hci155 | doi-access = }} severe stress,[http://www.merckmanuals.com/home/blood_disorders/white_blood_cell_disorders/lymphocytopenia.html Lymphocytopenia] from the Merck Manual Home Health Handbook intense or prolonged physical exercise (due to cortisol release),{{cite journal | vauthors = Robson PJ, Blannin AK, Walsh NP, Castell LM, Gleeson M | title = Effects of exercise intensity, duration and recovery on in vitro neutrophil function in male athletes | journal = International Journal of Sports Medicine | volume = 20 | issue = 2 | pages = 128–35 | date = February 1999 | pmid = 10190775 | doi = 10.1055/s-2007-971106 | publisher = Thieme | s2cid = 2572545 }} rheumatoid arthritis, sarcoidosis,{{cite journal | vauthors = Hedfors E, Holm G, Pettersson D | title = Lymphocyte subpopulations in sarcoidosis | journal = Clinical and Experimental Immunology | volume = 17 | issue = 2 | pages = 219–26 | date = June 1974 | pmid = 4549571 | pmc = 1554022 }} multiple sclerosis,{{cite journal | vauthors = Lim ZW, Elwood E, Naveed H, Galea I | title = Lymphopenia in treatment-naive relapsing multiple sclerosis | journal = Neurology | volume = 3 | issue = 5 | pages = e275 | date = October 2016 | pmid = 27559542 | pmc = 4982853 | doi = 10.1212/NXI.0000000000000275 }} and iatrogenic (caused by other medical treatments) conditions.

Lymphocytopenia is a frequent, temporary result from many types of chemotherapy, such as with cytotoxic agents or immunosuppressive drugs. Some malignancies that have spread to involve the bone marrow, such as leukemia or advanced Hodgkin's disease,{{cite journal | vauthors = Faguet GB | title = Quantitation of immunocompetence in Hodgkin's disease | journal = The Journal of Clinical Investigation | volume = 56 | issue = 4 | pages = 951–7 | date = October 1975 | pmid = 1159096 | pmc = 301951 | doi = 10.1172/JCI108175 }}{{cite journal | vauthors = Weiss RB, Brunning RD, Kennedy BJ | title = Hodgkin's disease in the bone marrow | journal = Cancer | volume = 36 | issue = 6 | pages = 2077–83 | date = December 1975 | pmid = 1203865 | doi = 10.1002/cncr.2820360924 | s2cid = 6194154 | doi-access = free }} also cause lymphocytopenia.

Another cause is infection with Influenza A virus subtype H1N1 (and other subtypes of the Influenza A virus) and is then often associated with Monocytosis;{{cite journal | vauthors = Merekoulias G, Alexopoulos EC, Belezos T, Panagiotopoulou E, Jelastopulu DM | title = Lymphocyte to monocyte ratio as a screening tool for influenza | journal = PLOS Currents | volume = 2 | pages = RRN1154 | date = March 2010 | pmid = 20383263 | pmc = 2847387 | doi = 10.1371/currents.rrn1154 | doi-access = free }} H1N1 was responsible for the Spanish flu, the 2009 flu pandemic and in 2016 for the Influenza-epidemic in Brazil.[http://www.healthmap.org/site/diseasedaily/article/over-1000-deaths-h1n1-outbreak-brazil-71216 Over 1,000 Deaths from H1N1 Outbreak in Brazil] {{Webarchive|url=https://web.archive.org/web/20160911151430/http://www.healthmap.org/site/diseasedaily/article/over-1000-deaths-h1n1-outbreak-brazil-71216 |date=2016-09-11 }} (article from 12 July 2016) The SARS disease caused lymphocytopenia.{{cite book |last=Low |first=Donald |authorlink=Donald Low |date=2004 |url= https://www.ncbi.nlm.nih.gov/books/NBK92467/ |pages= 63–71 |title=Learning from SARS: Preparing for the Next Disease Outbreak: Workshop Summary|chapter=Sars: Lessons from Toronto |publisher=National Academies Press (US)}} Among patients with laboratory-confirmed COVID-19 in Wuhan China through January 29th, 2020, 83.2 percent had Lymphocytopenia at admission.{{cite journal | vauthors = Guan, Wei-jie | title=Clinical Characteristics of Coronavirus Disease 2019 in China | journal = New England Journal of Medicine | date=February 28, 2020 | volume=382 | issue=18 | pages=1708–20 | doi=10.1056/NEJMoa2002032| pmid=32109013 | pmc=7092819 | doi-access=free }}

Large doses of radiation, such as those involved with nuclear accidents or medical whole body radiation, may cause lymphocytopenia.{{cite journal | vauthors = Venkatesulu BP, Mallick S, Lin SH, Krishnan S | title=A systematic review of the influence of radiation-induced lymphopenia on survival outcomes in solid tumors | journal = Critical Reviews in Oncology/Hematology | date=Mar 2018 | volume=123 | pages=42–51 | doi=10.1016/j.critrevonc.2018.01.003| pmid=29482778 | doi-access= }}

Lymphocytopenia is diagnosed when the complete blood count shows a lymphocyte count lower than the age-appropriate reference interval (for example, below 0.9 x 10⁹/L in an adult).{{citation needed|date=July 2020}}

Lymphocytopenia caused by Feline Leukemia Virus and Feline immunodeficiency virus retroviral infections is treated with Lymphocyte T-Cell Immune Modulator.{{Cite web |url=http://tcyte.com/ltci-product-info-feline-leukemia/the-science-behind-the-product/ |title=The Science Behind LTCI | Treatment for Cats with FIV and FeLV |access-date=2013-03-20 |archive-url=https://web.archive.org/web/20130702160828/http://tcyte.com/ltci-product-info-feline-leukemia/the-science-behind-the-product/ |archive-date=2013-07-02 |url-status=dead }}

{{Reflist}}

{{Medical resources

| DiseasesDB = 7677

| ICD10 = {{ICD10|D|72|8||d|72|8}}

| ICD9 = {{ICD9|288.8}}

| ICDO =

| OMIM =

| MedlinePlus =

| eMedicineSubj =

| eMedicineTopic =

| MeshID = D008231

| ICD10CM = {{ICD10CM|D72.810}}

}}

{{Lymphoid and complement immunodeficiency}}

Category:Lymphocytic disorders

Category:Immune system disorders

Category:Hematopathology