Neutropenia

Haematology · Abnormal laboratory result · updated 2026-11-09

BioMG follows French guidelines. Adapt it to the guidelines and the tests available where you practise.

Frequency: In the United States (NHANES 1999-2004 survey), neutrophils < 1.5 G/L in 0.79% of white participants, 4.5% of Black participants and 0.38% of participants of Mexican origin ^[1]; no French general-population data found.

ANC < 0.5 G/L (severe) OR ANC < 1.5 G/L with fever

In this situation, an urgent specialist consultation is recommended.
In febrile neutropenia, broad-spectrum antibiotic therapy targeting Gram-negative bacilli must be started urgently.

Detailed explanation and international comparison (in French): read it in English (machine translation)

0.5 G/L < ANC < 1.5 G/L, no fever, with viral context or risk behaviour

Laboratory tests

FBC
HIV serology
Hepatitis B serology
Hepatitis C serology
EBV serology
CMV serologyif needednon-French guidelineChronic or persistent neutropenia after an infection: CMV is among the first-line serology tests ^[3].
Parvovirus B19 serologyif needednon-French guidelineChronic or persistent neutropenia after an infection: parvovirus B19 is among the first-line serology tests ^[3].

Detailed explanation and international comparison (in French): read it in English (machine translation)

0.5 G/L < ANC < 1.5 G/L, no fever, with a recent drug (or vaccination)

Laboratory tests

FBC
To be done once a week until normalisation

Detailed explanation and international comparison (in French): read it in English (machine translation)

0.5 G/L < ANC < 1.5 G/L, no fever, known and ethnic (benign ethnic neutropenia)

With previous blood counts showing the neutropenia, no recurrent infection, a normal clinical examination and a compatible ethnic origin (Africans, African Americans, West Indians), the diagnosis is ethnic neutropenia and no further tests are needed

Detailed explanation and international comparison (in French): read it in English (machine translation)

Do not order

Further tests and treatment for established neutropenia associated with the Duffy-null phenotype: unnecessary ^[3].

0.5 G/L < ANC < 1.5 G/L, no fever, no specific context

Laboratory tests

FBC
Antinuclear antibodies (ANA)
Rheumatoid factor
Serum protein electrophoresis
AST
ALT
GGT
Alkaline phosphatase
Serum creatinine with eGFRif needednon-French guidelineRenal function tests, with liver function, are among the first-line tests for unexplained isolated neutropenia in adults ^[3].
Vitamin B12if neededNutritional deficiencies are among the first-line tests for unexplained isolated neutropenia ^[3]; the Revue du Praticien cites deficiencies among the causes ^[2].
Folateif neededNutritional deficiencies are among the first-line tests for unexplained isolated neutropenia ^[3]; the Revue du Praticien cites deficiencies among the causes ^[2].
TSH
Free T4if neededOnly if TSH is abnormal, as a reflex test (free T4; free T3 is of interest only if TSH is low with a normal free T4).
Free T3if neededOnly if TSH is abnormal, as a reflex test (free T4; free T3 is of interest only if TSH is low with a normal free T4).
HIV serologyif needednon-French guidelineThe NHS Lothian guide (Scotland) asks for them in any persistent neutropenia, with blood film, vitamin B12, folate and ferritin ^[5]; the review by Njue (2025) also recommends viral serology (HIV, HBV, HCV, EBV, CMV, parvovirus B19) in unexplained isolated neutropenia ^[3]. They are firm lines in the tab “viral context or at-risk behaviour”.
Hepatitis B serologyif needednon-French guidelineThe NHS Lothian guide (Scotland) asks for them in any persistent neutropenia, with blood film, vitamin B12, folate and ferritin ^[5]; the review by Njue (2025) also recommends viral serology (HIV, HBV, HCV, EBV, CMV, parvovirus B19) in unexplained isolated neutropenia ^[3]. They are firm lines in the tab “viral context or at-risk behaviour”.
Hepatitis C serologyif needednon-French guidelineThe NHS Lothian guide (Scotland) asks for them in any persistent neutropenia, with blood film, vitamin B12, folate and ferritin ^[5]; the review by Njue (2025) also recommends viral serology (HIV, HBV, HCV, EBV, CMV, parvovirus B19) in unexplained isolated neutropenia ^[3]. They are firm lines in the tab “viral context or at-risk behaviour”.

Detailed explanation and international comparison (in French): read it in English (machine translation)

0.5 G/L < ANC < 1.5 G/L, no fever, no specific context, with negative tests above

Laboratory tests

Anti-neutrophil antibodies
T-cell clonality by PCR on blood lymphocytes
FBC: to be done twice a week for 5 weeks
Serum copperif needednon-French guidelineSecond line in chronic unexplained isolated neutropenia ^[3].

Detailed explanation and international comparison (in French): read it in English (machine translation)

Sources (23)