Clinical trial NCT06431958: Droplet Digital PCR and PCR-free BIOSensors for the Detection of Resistance-associated SNPs in Pneumocystis Jirovecii
Official title: Droplet Digital PCR and PCR-free BIOSensors for the Detection of Resistance-associated SNPs in Pneumocystis Jirovecii
Study type: OBSERVATIONAL
Overall status: ACTIVE_NOT_RECRUITING
Conditions: Pneumocystis Pneumonia
Keywords: Pneumocystis jirovecii
mutant
anti-microbial resistance
DHPS
DHFR
Cytochrome b
IMPDH
Lead sponsor: University Hospital, Brest
Sponsor class: OTHER
First posted: 2024-05-29
Enrollment: 300
Sex: ALL
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: CASE_ONLY
Time perspective: RETROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Patients in whom P. jirovecii was detected in a pulmonary sample (bronchoalveolar lavage, sputum, bronchial aspiration, oropharyngeal rinse, nasopharyngeal sample) can be included in the study

Brief summary: The main objective of the proposed research is to identify Pneumocystis jirovecii mutant strains on 4 genes encoding therapeutic targets such as dihydropteroate synthase (DHPS), dihydrofolate reductase (DHFR), cytochrome b (CYB), inosine-5'-monophosphate dehydrogenase (IMPDH) and therefore to assess the prevalence of potentially resistant strains in patients infected with P. jirovecii.

Detailed description: Pneumocystis jirovecii (P. jirovecii) is an opportunistic pathogenic fungus responsible for pulmonary infection or Pneumocystis pneumonia (PCP) in immunocompromised patients. There is currently no system for its in vitro culture. The diagnostic methods used are mainly based on molecular biology techniques which also allow the detection and analysis of single nucleotide polymorphisms (SNPs), particularly at the level of genes coding for the targets of molecules widely used in the prevention and treatment of PCP. These SNPs may represent missense mutations potentially associated with treatment resistance. They may result from exposure of patients to these treatments before the development of P. jirovecii infection. However, data concerning the prevalence of these mutations remains scarce, particularly in France. Methods for detecting these mutations based on PCR followed by DNA sequencing have limitations in terms of sensitivity. The evaluation of new, more sensitive and rapid tools for the detection and characterization of pathogens in this context is necessary.

The main objective of the proposed research is to identify P. jirovecii mutant strains on 4 genes encoding therapeutic targets such as dihydropteroate synthase (DHPS), dihydrofolate reductase (DHFR), cytochrome b (CYB), inosine-5'-monophosphate dehydrogenase (IMPDH) and therefore to assess the prevalence of potentially resistant strains in patients infected with P. jirovecii.

The secondary objectives are:

* to determine the factors associated (e.g. exposure to treatments) with mutant P. jirovecii strains
* to determine the impact of mutations on the effectiveness of anti-Pneumocystis treatment (e.g. favorable vs. unfavorable evolution of the infection)
* to evaluate two methods - digital droplet PCR and biosensors without PCR - for the detection and characterization of mutations associated with resistance in Pneumocystis jirovecii

Eligibility criteria: Inclusion Criteria:

* Patients in whom P. jirovecii was detected in a pulmonary sample (bronchoalveolar lavage, sputum, bronchial aspiration, oropharyngeal rinse, nasopharyngeal sample)
* No opposition
* Patient affiliated to a social security system

Exclusion Criteria:

* Patients under legal protection (guardianship, curatorship)
* Refusal to participate

Primary outcomes:
measure: Presence of specific strains of Pneumocystis jirovecii potentially resistant to treatments in patients infected with this fungus
timeFrame: at inclusion
Secondary outcomes:
measure: to determine the factors associated (e.g. exposure to treatments) with P. jirovecii mutant strains
timeFrame: at inclusion
Other outcomes:
measure: to determine the impact of mutations on the effectiveness of anti-Pneumocystis treatment (e.g. favorable vs. unfavorable evolution of the infection)
timeFrame: 1 month and 3 month
measure: to evaluate two methods - digital droplet PCR and biosensors without PCR - for the detection and characterization of mutations associated with resistance in Pneumocystis jirovecii
timeFrame: at inclusion
Locations:
city: Brest
country: France
facility: Chu Brest
Study officials:
References:
citation: Hoffmann CV, Nevez G, Moal MC, Quinio D, Le Nan N, Papon N, Bouchara JP, Le Meur Y, Le Gal S. Selection of Pneumocystis jirovecii Inosine 5'-Monophosphate Dehydrogenase Mutants in Solid Organ Transplant Recipients: Implication of Mycophenolic Acid. J Fungi (Basel). 2021 Oct 10;7(10):849. doi: 10.3390/jof7100849.
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citation: Kojabad AA, Farzanehpour M, Galeh HEG, Dorostkar R, Jafarpour A, Bolandian M, Nodooshan MM. Droplet digital PCR of viral DNA/RNA, current progress, challenges, and future perspectives. J Med Virol. 2021 Jul;93(7):4182-4197. doi: 10.1002/jmv.26846. Epub 2021 Mar 11.
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