Histiocytosis in Injecting Drug Users

• Conditions: Histiocytosis
• Interventions: Diagnostic Test: Chitotriosidase; Diagnostic Test: Mass spectrometry; Diagnostic Test: X-ray spectromicroscopy; Diagnostic Test: Fluorescence microscopy; Diagnostic Test: Transcriptomics

• Registration Number: NCT06573671
• Lead Sponsor: Tampere University Hospital

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.

Detailed Description

We will search for comprehensive patient data (disease history, findings, complications, laboratory findings, histopathology, and imaging) from patient records of a single university hospital. Coded histiocytosis-positive tissue samples will be compared to biobank samples from corresponding tissues from healthy and other other histiocytosis tissue samples to show polyvinylpyrrolidone storage with novel methodologies.

In addition, if study participant who is followed up, signs informed consent, monocytes are separated from a blood sample, differentiated to macrophages, and exposed to polyvinylpyrrolidone. Various novel methods will be utilized to explore polyvinylpyrrolidone within histiocytes.

Study Timeline

• Study Start: 2023-05-29
• Status Verified: 2024-02
• Study First Submitted: 2024-08-23
• Study First Submitted QC: 2024-08-23
• Last Update Submitted: 2024-08-23
• Study First Posted: 2024-08-27
• Last Update Posted: 2024-08-27
• Primary Completion: 2030-12-31
• Study Completion: 2030-12-31

Recruitment & Eligibility

• Status: ENROLLING_BY_INVITATION
• Sex: All
• Target Recruitment: 30

Inclusion Criteria

• All identified adult patients in our records with a history of injecting drug use by dissolving tablets containing polyvinylpyrrolidone and (suspected) PVP-histiocytosis

Exclusion Criteria

• Other histiocytosis diagnosed by tissue samples and clinical information

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
Injecting drug induced histiocytosis	X-ray spectromicroscopy	No intervention
Injecting drug induced histiocytosis	Mass spectrometry	No intervention
Injecting drug induced histiocytosis	Transcriptomics	No intervention
Injecting drug induced histiocytosis	Chitotriosidase	No intervention
Injecting drug induced histiocytosis	Fluorescence microscopy	No intervention

Primary Outcome Measures

Name	Time	Method
Frequency of disease manifestations	10 years	To describe phenotype

Secondary Outcome Measures

Name	Time	Method
Transcriptomics analysis	10 years	Search for abnormalities in cases compared with controls
Microscopic fluorescence positive tissue	10 years	Search for fluorescence signal
Frequency of elevated chitotriosidase activity	10 years	Is chitotriosidase activity associated with PVP histiocytosis
Mortality	10 years	Mortality
X-ray spectromicroscopy	10 years	search for signal within cells
Pyrolysis mass spectrometry	10 years	search for signal within cells

Trial Locations

Locations (1)

Tampere University Hospital; 🇫🇮 Tampere, Pirkanmaa, Finland