Brief Summary

The goal of this observational study is to describe a new disease condition of histiocytosis related to injecting drug use, its preconditions, symptoms, signs, findings, and prognosis in a detailed and systematic patient series in one referral center. The main question\[s\] it aims to answer are:

to find specific histologic features in different tissues to help the differential diagnosis from other histiocytoses
to describe the value of chitotriosidase activity to screen this condition
to describe the value of various tissue biopsies in confirming the diagnosis
to describe the nature of polyvinylpyrrolidone accumulation in tissue macrophages by novel special microscopic techniques
to find new tandem mass spectrometry methodology to prove polyvinylpyrrolidone accumulation in macrophages
to show that polyvinylpyrrolidone treatment activates macrophages to histiocytes and causes povidone accumulation within the cells in in vitro experiments
to evaluate the pathology of macrophage activation to histiocytes by transcriptomics The patient history will be collected from the data produced by follow-up of cases followed up in a single center. A subgroup of participants will be given an opportunity to sign informed consent to give access to/donate blood and tissue samples to search for techniques to prove polyvinylpyrrolidone storage within histiocytes, and to search for transcriptomics signal(s) in histiocytes. Researchers will compare blood and tissue samples from the biobank as controls.

Trial Health

On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment

participants targeted

Target at below P25 for all trials

Timeline

53mo left

Started May 2023

Longer than P75 for all trials

Geographic Reach

1 country

1 active site

Status

enrolling by invitation

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

7.6 years study duration

Study Progress42%

May 2023Dec 2030

Study Start

First participant enrolled

May 29, 2023

Completed

1.2 years until next milestone

First Submitted

Initial submission to the registry

August 23, 2024

Completed

4 days until next milestone

First Posted

Study publicly available on registry

August 27, 2024

Completed

6.3 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

December 31, 2030

Expected

Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

December 31, 2030

Last Updated

September 10, 2025

Status Verified

September 1, 2025

Enrollment Period

7.6 years

First QC Date

August 23, 2024

Last Update Submit

September 3, 2025

Conditions

Histiocytosis

Keywords

intravenousdrug abusepolyvinylpyrrolidonePVP

Outcome Measures

Primary Outcomes (1)

Frequency of disease manifestations
To describe phenotype
10 years

Secondary Outcomes (6)

Frequency of elevated chitotriosidase activity
10 years
Mortality
10 years
Microscopic fluorescence positive tissue
10 years
Scanning electron microscope with energy-dispersive X-ray spectroscopy
10 years
Pyrolysis mass spectrometry
10 years
+1 more secondary outcomes

Study Arms (1)

Injecting drug induced histiocytosis

No intervention

Diagnostic Test: ChitotriosidaseDiagnostic Test: Mass spectrometryDiagnostic Test: scanning electron microscope with energy-dispersive X-ray spectroscopyDiagnostic Test: Fluorescence microscopyDiagnostic Test: Transcriptomics

Interventions

ChitotriosidaseDIAGNOSTIC_TEST

The amount of patients with increased chitotriosidase, and the extent of elevation of chitotriosidase