Histiocytosis in Injecting Drug Users

Tampere University Hospital

Status

Invitation-only

Conditions

Histiocytosis

Treatments

Diagnostic Test: Fluorescence microscopy

Diagnostic Test: Transcriptomics

Diagnostic Test: Mass spectrometry

Diagnostic Test: scanning electron microscope with energy-dispersive X-ray spectroscopy

Diagnostic Test: Chitotriosidase

Study type

Observational

Funder types

Other

Identifiers

NCT06573671

R20105

Details and patient eligibility

About

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.

Full 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.

Enrollment

30 estimated patients

Sex

All

Ages

18 to 70 years old

Volunteers

No Healthy Volunteers

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