Histiocytosis in Injecting Drug Users

September 3, 2025 updated by: Tampere University Hospital

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.

Study Overview

Status

Enrolling by invitation

Conditions

Intervention / Treatment

Detailed Description

Comprehensive patient data (disease history, findings, complications, laboratory findings, histopathology, and imaging) will be obtained 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 histiocytosis tissue samples to show polyvinylpyrrolidone storage with novel methodologies.

In addition, if a study participant who is followed up clinically, 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 Type

Observational

Enrollment (Estimated)

30

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Finland
    • Pirkanmaa
      • Tampere, Pirkanmaa, Finland, 33101
        • Tampere University Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

N/A

Sampling Method

Probability Sample

Study Population

Adult patients admitting to intravenous use of dissolved tablets (indicated for oral use) containing polyvinylpyrrolidone (PVP30) and positive tissue sample in any tissue biopsy compatible with features of histiocytosis caused by PVP30

Description

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 Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Injecting drug induced histiocytosis
No intervention
Diagnostic test: Chitotriosidase
The amount of patients with increased chitotriosidase, and the extent of elevation of chitotriosidase
Diagnostic test: Mass spectrometry
to show polyvinylpyrrolidone presence in histiocytes of injecting drug users compared to controls
Diagnostic test: scanning electron microscope with energy-dispersive X-ray spectroscopy
to show polyvinylpyrrolidone presence in histiocytes of injecting drug users compared to controls
Diagnostic test: Fluorescence microscopy
to show polyvinylpyrrolidone presence in histiocytes of injecting drug users compared to controls
Diagnostic test: Transcriptomics
To describe pathologic signals of polyvinylpyrrolidone-exposed in vitro histiocytes of injecting drug users compared to control samples

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Frequency of disease manifestations
Time Frame: 10 years
To describe phenotype
10 years

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Mortality
Time Frame: 10 years
Mortality
10 years
Frequency of elevated chitotriosidase activity
Time Frame: 10 years
Is chitotriosidase activity associated with polyvinylpyrrolidone histiocytosis
10 years
Microscopic fluorescence positive tissue
Time Frame: 10 years
Search for specific polyvinylpyrrolidone fluorescence signal
10 years
Scanning electron microscope with energy-dispersive X-ray spectroscopy
Time Frame: 10 years
search for specific polyvinylpyrrolidone signal within cells
10 years
Pyrolysis mass spectrometry
Time Frame: 10 years
search for specific polyvinylpyrrolidone signal within cells
10 years
Transcriptomics analysis
Time Frame: 10 years
Search for immunologic pathway-specific abnormalities to guide treatment in cases compared with controls
10 years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Tampere University Hospital

Collaborators

University of Turku
University of Helsinki
Tampere University
University of Oulu

Investigators

  • Principal Investigator: Pasi I Nevalainen, MD, PhD, Senior consultant

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

May 29, 2023

Primary Completion (Estimated)

December 31, 2030

Study Completion (Estimated)

December 31, 2030

Study Registration Dates

First Submitted

August 23, 2024

First Submitted That Met QC Criteria

August 23, 2024

First Posted (Actual)

August 27, 2024

Study Record Updates

Last Update Posted (Estimated)

September 10, 2025

Last Update Submitted That Met QC Criteria

September 3, 2025

Last Verified

September 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • R20105

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Study data can only be acquired by proper inquiry to the national authority Findata by law

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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