A Prospective Observational Study on the Utility of Rapid GM-CSF Autoantibody Testing (LineCheck APAP) in Patients with Undiagnosed Diffuse Pulmonary Ground-Glass Opacities

A Prospective Observational Study on the Utility of Rapid GM-CSF Autoantibody Testing (LineCheck APAP) in Patients with Undiagnosed Diffuse Pulmonary Ground-Glass Opacities - RAPIDXGGO Study

Status

Active, not recruiting

Phases

Unknown

Study type

Observational

Source

JPRN

Registry ID

JPRN-UMIN000061510

Enrollment

350

Registered

2026-05-30

Start date

2026-08-01

Completion date

Unknown

Last updated

2026-09-14

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Undiagnosed diffuse lung diseases presenting with diffuse ground-glass opacities on HRCT

Interventions

None listed

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: 1) Patients evaluated or treated at Kumamoto University Hospital, Kyoto University Hospital, Kyorin University Hospital, Institute of Science Tokyo Hospital, Chiba University Hospital, Saitama Red Cross Hospital, or Tohoku University Hospital; 2) 18 years and older; 3) undiagnosed DLDs presenting with diffuse GGOs on HRCT at the initial visit; and 4) patients who received a written explanation of the study and provided written informed consent.

Exclusion criteria

Exclusion criteria: 1) Patients with an obvious mass lesion or localized nodular lesion; 2) patients with an acute clinical course showing rapid progression within 1 month; 3) patients with an already identified cause of DLD, such as drug-induced lung injury; 4) patients with overt cardiac disease causing pulmonary congestion, such as heart failure; 5) cases judged to be inappropriate for participation by the treating physician at the time of HRCT assessment; and 6) patients currently participating in another interventional study that precludes participation in this study.

Design outcomes

Primary

Measure	Time frame
Co-primary outcomes assessed within 6 months after registration are: 1) the positivity rate of rapid GM-CSF autoantibody test in patients with unexplained diffuse GGOs, 2) the proportion of patients with final diagnosis of APAP among GM-CSF antibody-positive cases (positive predictive value), and 3) the negative predictive value of the test among GM-CSF antibody-positive cases.	—

Secondary

Measure	Time frame
1) Descriptive analysis of the clinical characteristics of GM-CSF antibody-positive patients, 2) establishment and storage of a specimen repository, and 3) comparison between the results of KBM LineCheck APAP and quantitative GM-CSF antibody levels measured by ELISA.	—

Countries

Japan

Contacts

Public ContactKimitaka Akaike

Kumamoto University Hospital Department of Respiratory Medicine

demio0601@gmail.com+81963635012

Outcome results