Related Experiment Video
Updated: Oct 4, 2026
Murine Nasal Lavage Fluid Collection without Blood Contamination
Published on: July 11, 2025
Chronic mild neutropenia in adults: relation to IgG3 deficiency and infection susceptibility
R Karlström1, R Gustafson, J Palmblad
1Department of Medicine, Division of Hematology, The Karolinska Institutet at Huddinge University Hospital, S-141 86 Stockholm, Sweden.
Objectives:
Chronic mild neutropenias (NP, i.e. absolute neutrophil blood counts/ANC/0.5-1.5 x 10(9) L(-1)) are accompanied by a variable infection susceptibility, which may or may not be as a result of concomitant conditions. Here, we assessed whether such patients also displayed an immunoglobulin deficiency and if this condition contributed to infection proneness.
Design, Setting And Subjects:
Thirty consecutive adult Caucasian patients with chronic mild NP were followed at one university hospital for up to 28 years. Comparisons were made with 49 IgG3 deficiency patients at an immunodeficiency clinic.
Main Outcome Measures:
Recorded infections, ANC and serum immunoglobulin levels; flow cytometry assessments of blood lymphocyte subsets and tests for autoimmunity were run to determine neutropenia subtypes.
Results:
Forty per cent of the NP patients were treated for severe or recurrent infections. The mean IgG3 value for the NP patients was significantly lower than for healthy controls (P < 0.005) and 33% of the patients displayed IgG3 values below the reference values (i.e. below 0.21 g L(-1)), and an additional 13% had IgG3 values within the range others consider low (0.21-0.41 g L(-1)). Unexpectedly, neutropenic IgG3 deficiency patients exhibited less infection proneness than those with normal IgG3 values (P=0.03). Patients with autoimmune, large granular lymphocyte-associated or idiopathic NP had IgG3 deficiency in 63, 44 and 38%, respectively. In addition, none of IgG3 deficiency patients followed at the immunodeficiency clinic displayed neutropenia.
Conclusion:
IgG3 deficiency is common amongst chronic mild neutropenia patients, particularly in those with autoimmune background, but contributes not significantly to infection susceptibility.
Insights
Chronic mild neutropenia patients often have IgG3 deficiency, especially those with autoimmune conditions. However, this deficiency does not significantly increase their susceptibility to infections.
Area of Science:
- Immunology
- Hematology
Background:
- Chronic mild neutropenia (NP) is associated with variable infection susceptibility, potentially due to co-existing conditions.
- The role of immunoglobulin deficiency in infection proneness among NP patients requires further investigation.
Purpose of the Study:
- To assess the prevalence of immunoglobulin deficiency in patients with chronic mild neutropenia.
- To determine if immunoglobulin deficiency contributes to increased infection susceptibility in these patients.
Main Methods:
- A cohort of 30 adult Caucasian patients with chronic mild neutropenia was followed for up to 28 years.
- Serum immunoglobulin levels, absolute neutrophil counts (ANC), lymphocyte subsets, and autoimmunity markers were analyzed.
- Comparisons were made with 49 patients diagnosed with IgG3 deficiency.
Main Results:
- Forty percent of NP patients experienced severe or recurrent infections.
- NP patients exhibited significantly lower mean IgG3 levels compared to healthy controls (P < 0.005).
- IgG3 deficiency was prevalent in 33% of NP patients, with an additional 13% having low-normal IgG3 levels. Unexpectedly, neutropenic patients with IgG3 deficiency showed less infection proneness (P=0.03).
Conclusions:
- IgG3 deficiency is common in chronic mild neutropenia, particularly in autoimmune cases.
- Despite its prevalence, IgG3 deficiency does not appear to be a significant contributor to infection susceptibility in this patient group.
Related Concept Videos
01:25Immunodeficiency Diseases
There are three main causes of immunodeficiency disorders...
01:27Disorders of Leukocytes
Leukopenia may result from bone marrow disorders, autoimmune diseases, and infectious diseases. For example, conditions such as multiple myeloma and aplastic anemia can impair the bone marrow's ability to produce adequate leukocytes. Similarly, autoimmune diseases like lupus and viral infections such as HIV can prompt the immune system...
01:25Inflammatory Bowel Disease III: Crohn's Disease
01:27Cryptococcal Meningitis