MFAP4 Antibody

What is MFAP4 and where is it primarily expressed in human tissues?

MFAP4 is an extracellular matrix glycoprotein containing a fibrinogen C-terminal domain and an N-terminal integrin-binding motif. It is involved in calcium-dependent cell adhesion and intercellular interactions . Quantitative real-time PCR analysis shows highest MFAP4 mRNA expression in heart, intestine, and lung tissues . Immunohistochemical studies reveal MFAP4 is predominantly localized to elastic fibers in blood vessels and connective tissues across multiple organs, including:

• Pulmonary arterioles and interalveolar walls of the lung

• Lamina propria of the trachea

• Blood vessels in the heart

• Central arteries and trabeculae of the spleen

• Connective tissues in portal areas of the liver

• Blood vessels of the kidney

• Elastic fibers in the skin and adrenal gland

What applications can MFAP4 antibodies be used for in laboratory research?

MFAP4 antibodies have been validated for multiple research applications:

The antibody 17661-1-AP has been specifically tested and shows reactivity with human, mouse, and rat samples across these applications .

How is MFAP4 measured in clinical and research samples?

MFAP4 is typically measured using a sandwich ELISA (enzyme-linked immunosorbent assay) based on two monoclonal anti-MFAP4 antibodies. This methodology has been optimized and calibrated with recombinant MFAP4 standards .

Key parameters of the validated ELISA include:

• Practical working range: 4-75 U/ml

• Maximum intra-assay variation: 8.7%

• Maximum inter-assay variation: 6.6%

• Average serum concentration in general population: 18.9 ± 8.4 U/ml (median 17.3 U/ml)

What pre-analytical factors affect MFAP4 measurements in biological samples?

• Sample tube type

• Time between collection and processing

• Temperature conditions during processing and storage

When designing MFAP4 measurement protocols, it's important to maintain consistency in these parameters across all samples to minimize pre-analytical variability.

What is the recommended protocol for immunohistochemical detection of MFAP4?

For optimal immunohistochemical detection of MFAP4 in tissue sections:

• Perform antigen retrieval preferably with TE buffer pH 9.0 (alternatively, citrate buffer pH 6.0 may be used)

• Use anti-MFAP4 antibodies at dilutions between 1:20-1:200, optimizing for each tissue type

• Validate specificity using appropriate negative controls (omission of primary antibody)

• Counterstain with Mayer's hematoxylin for optimal visualization

• Examine elastic fibers in blood vessels and surrounding connective tissues where MFAP4 is predominantly expressed

Tissues showing particularly strong MFAP4 expression include lung, heart, and spleen, making these good positive control tissues for protocol optimization.

How does MFAP4 function as a biomarker in liver disease?

MFAP4 has been validated as a systemic biomarker that is significantly elevated in patients suffering from hepatic cirrhosis . The protein's association with elastic fibers and connective tissue fibers in the extracellular matrix makes it particularly relevant for monitoring diseases characterized by increased ECM turnover.

Research demonstrates that serum MFAP4 measurements reflect disease-induced processes rather than constitutional variations, which supports its utility as a liver fibrosis marker . The relatively low heritability (h² = 0.24) and limited basal variation further support MFAP4's value as a biomarker reflecting pathological processes rather than genetic factors.

What factors influence basal MFAP4 levels in healthy individuals?

Several demographic and physiological factors affect baseline MFAP4 levels:

When using MFAP4 as a biomarker, these variables should be considered and adjusted for in statistical analyses to isolate disease-specific effects .

How can MFAP4 be used as a predictive biomarker for treatment response in inflammatory diseases?

Research indicates that MFAP4 has potential as a predictive biomarker for response to biological therapy in chronic inflammatory diseases (CIDs). In a prospective multi-center cohort study of 211 patients with various CIDs:

• Patients with high MFAP4 levels (upper tertile) showed improved treatment response to biological therapy compared to those with lower levels

• When adjusting for confounders (CID type, age, sex, smoking status, and BMI), patients in the high MFAP4 group had an adjusted odds ratio of 2.28 (95% CI: 1.07 to 4.85) for positive treatment outcome

• Disease-specific patterns were observed, with high MFAP4 predicting positive response in rheumatoid arthritis, psoriatic arthritis, axial spondyloarthritis, and ulcerative colitis, but not in Crohn's disease

These findings suggest MFAP4 could support personalized medicine approaches by identifying patients most likely to benefit from biological treatments.

What methodological approach should be used when studying MFAP4 in fibrosis-related pathologies?

When investigating MFAP4 in fibrosis-related pathologies, researchers should:

• Measure both tissue and circulating MFAP4 levels to establish correlation between local and systemic expression

• Use complementary techniques including:

  • ELISA for quantitative measurement in serum/plasma

  • Immunohistochemistry to assess tissue distribution and co-localization with other ECM components

  • Western blot to evaluate protein expression levels and potential fragmentation

• Control for confounding factors known to affect MFAP4 levels (age, sex, BMI, smoking status)

• Consider disease stage and progression rate, as MFAP4 may reflect active ECM remodeling processes

• Incorporate longitudinal measurements to assess dynamic changes during disease progression or treatment

This multi-modal approach provides comprehensive characterization of MFAP4's role in fibrotic processes.

How can genetic versus environmental contributions to MFAP4 expression be distinguished in research studies?

Twin studies have provided insights into the genetic and environmental contributions to MFAP4 expression. Research shows:

• MFAP4 has a relatively low heritability of h² = 0.24, suggesting a stronger environmental than genetic influence

• A model including additive genetic factors and shared and non-shared environmental factors best explains the variation in MFAP4 levels

• The limited basal variation suggests that increased MFAP4 levels are primarily reflective of disease-induced processes rather than genetic predisposition

Researchers studying MFAP4 should:

• Consider both genetic and environmental factors in study design

• Use statistical models that account for these components when analyzing MFAP4 variation

• Interpret elevated MFAP4 as more likely resulting from pathological processes than from genetic variation

What are the technical considerations for optimizing antibody-based detection of MFAP4 in complex tissue samples?

When optimizing MFAP4 detection in complex tissue samples:

• Antibody selection: Use validated antibodies like monoclonal anti-MFAP4 (HG-HYB 7-14) for immunohistochemistry or 17661-1-AP for Western blot, IHC, and IF applications

• Tissue-specific optimization:

  • For vascular-rich tissues (lung, heart), focus on elastic fibers in vessel walls

  • For liver, examine both blood vessels and connective tissues in portal areas

  • For skin, target the dermal elastic fiber network

• Antigen retrieval optimization:

  • Primary recommendation: TE buffer pH 9.0

  • Alternative: citrate buffer pH 6.0

  • Optimize time and temperature for each tissue type

• Background reduction:

  • Include appropriate blocking steps to minimize non-specific binding

  • Use tissue-matched negative controls

  • Consider autofluorescence quenching for IF applications in tissues with high collagen content

• Signal amplification:

  • Consider tyramide signal amplification for tissues with low MFAP4 expression

  • Optimize secondary antibody concentration to balance signal strength and specificity

These optimizations ensure reliable detection of MFAP4 across different experimental conditions and tissue types.

How can MFAP4 antibodies be integrated into multiplex assays for studying complex disease mechanisms?

To integrate MFAP4 antibodies into multiplex assays:

• Antibody compatibility testing:

  • Verify cross-reactivity profiles of anti-MFAP4 antibodies with other antibodies in the multiplex panel

  • Ensure epitope accessibility when using multiple antibodies targeting different ECM components

• Multiplex immunofluorescence approach:

  • Use spectrally distinct fluorophores for simultaneous detection of MFAP4 and other markers

  • Consider sequential antibody labeling techniques if direct multiplexing causes interference

  • Implement spectral unmixing for accurate signal separation

• Multiplex protein assays:

  • Validate MFAP4 antibodies in bead-based multiplex assays (e.g., Luminex)

  • Optimize antibody pairs to minimize cross-reactivity in sandwich immunoassays

  • Calibrate with appropriate standards to ensure quantitative accuracy

• Data integration strategies:

  • Correlate MFAP4 expression with other ECM components and disease markers

  • Apply multivariate statistical methods to identify relationships between MFAP4 and other biomarkers

  • Develop algorithms that incorporate MFAP4 into multi-marker disease prediction models

This integrated approach allows researchers to position MFAP4 within broader pathophysiological contexts.

What are the current limitations in MFAP4 antibody research and potential solutions?

Current limitations and potential solutions in MFAP4 antibody research include:

Addressing these limitations will advance the utility of MFAP4 antibodies in both research and clinical applications.