Investigation of Pneumocystis jirovecii pneumonia and colonization in latrogenically immunosuppressed and immunocompetent patients Iyatrojenik Immünosüpresif ve Immünokompetan Hastalarda Pneumocystis jirovecii Pnömonisi ve Kolonizasyonunun Araştirilmasi

Pneumocystis pneumonia (PCP) is a potentially life-threatening infection for the immunocompromized patients. However, Pneumocystis jirovecii colonization can also be detected in healthy individuals and in patients with various underlying lung diseases. The aim of this study was to evaluate the immunocompetent and iatrogenically immunosuppressed patients in terms of PCP and P.jirovedi colonization. A total of 92 patients (66 male, 26 female; age range: 18-93 years, median: 58.5) who underwent bronchoscopy due to various pulmonary symptoms between January 2011-April 2014, were included in the study. Of these patients, 65 were under immunosuppressive therapy (38 were treated with anti-cancer drugs, 15 with anti-rejection/immunomodulatory drugs and 12 with corticosteroids), while 27 were immunocompetent. Bronchoalveolar lavage (BAL) fluids were evaluated for the presence of P.jirovedi mitochondrial gene coding ribosomal large subunit (mtLSUrRNA) with nested PCR (nPCR) method. All of the samples were also examined by Giemsa and Gomori's methenamine silver (CMC) staining methods. P.jirovedi DNA was detected in 31 (33.7%) out of 92 BAL samples by nPCR. Although six immunosuppressed patients were positive in the first round of amplification, 26 of 65 (40%) immunosuppressed and five of 27 (18.5%) immunocompetent patients were positive with nPCR. P.jirovedi cysts and trophozoites were detected in only five (16.1 %) of the 31 nPCR positive samples. The probability of being immunosuppressive among nPCR positive cases was statistically higher than nPCR negative cases (Χ2= 3.940; p= 0.047). This difference was more significant in organ transplant recipients and patients under anti-rejection/immunomodulatory treatment (Χ2= 6.715, p= 0.01; Χ2= 5.550, p= 0.018, respectively). When clinical, laboratory and radiological findings of nPCR positive patients were considered, five patients (2 kidney transplant, 1 bone marrow transplant, 1 interstitial lung disease and 1 lung cancer case) in immunosuppressed group were interpreted as "definite PCP" and eight patients (2 kidney transplant, 1 leukemia, 1 connective tissue disease, 1 Wegener's granulomatosus, 2 rheumatoid arthritis and 1 lung cancer case) were interpreted as "probable PCP". Other 18 (19.6%) nPCR positive patients, of them 13 were immunosuppressive and five were immunocompetent, were considered as "P.jirovedi colonization". The colonization rate was determined as 50% (13/26) in immunosuppressive patients, and was mostly detected in patients with hematological malignancies (4/13), followed by patients with solid tumors (3/13) and organ transplantations (3/13). On the other hand, all of the nPCR positive immunocompetent patients (5/5) were evaluated as colonization. In this study significant data was obtained about P.jirovedi epidemiology in our country. Our results also showed that iatrogenically immunosuppressed patients are under risk of PCP and nPCR method is more sensitive than conventional PCR and classical staining methods in the diagnosis of these patients

Evaluation of pulmonary microsporidiosis in iatrogenically immunosuppressed patients

Introduction: Microsporidia spp. are ubiquitous and infect a wide variety of intervertebrates and vertebrates, including humans. Pulmonary microsporidiosis, characterized by nonspecific symptoms like fever, cough and dyspnea, is often overlooked in the differential diagnosis of pulmonary infections in immunsupressed patients. In this study, we aimed to determine the prevalence of pulmonary microsporidiosis in iatrogenically immunosuppressed patients and to evaluate the patient characteristics

Absence of dihydropteroate synthase gene mutations in Pneumocystis jirovecii strains isolated from Aegean region of Turkey

Sulfonamide group drugs and their antimetabolite combinations are the most preferred drugs in the treatment and prophylaxis of Pneumocystis jirovecii pneumonia (PCP). Especially with the long-term use of trimethoprim-sulfamethoxazole (TMP-SMX) and dapsone, certain point mutations in the Pneumocystis jirovecii (P. jirovecii) dihydropteroate synthase (DHPS) gene are known to play an important role in the development of resistance. In the present study, we investigated the 165th and 171st nucleotide mutations in the DHPS gene in the P. jirovecii isolates from immunosuppressed and immunocompetent cases. P. jirovecii isolates from the bronchoalveolar lavage fluid (BALF) samples of 31 hospitalized cases and lung tissue samples of 37 autopsy cases were included in the study. For the analysis of wild-type and mutant genotypes, after the touchdown-PCR amplification method, the restriction fragment length polymorphism (RFLP) method was used. In this study, P. jirovecii DHPS gene was amplified in 28 of 68 (41%) of the samples. The RFLP method revealed that all the isolates in which the DHPS gene was amplified were considered as wild-type genotypes. To our knowledge, this present study is the first study in Turkey investigating P. jirovecii DHPS gene mutations associated with the sulfonamide resistance. All the isolates showed a wild-type pattern indicating that the occurrence of P. jirovecii DHPS mutations in Turkey is very low or absent

Evaluation of Trichinella Cross-Reactions in the Serological Diagnosis of Toxocariasis

Toxocariasis caused by the nematode larvae of the Toxocara genus is a worldwide parasitic zoonosis. Diagnosis of human toxocariasis commonly relies on serological tests since the symptoms and signs of Toxocara infection are not pathognomonic. However Toxocara larval excretory-secretory (TES) antigen used in serological tests may exhibit low specificity due to the cross-reactions between related helminth infections such as ascariasis, anisakiasis, strongyloidosis and filariasis. In this study, we aimed to evaluate the possible effect of Trichinella cross-reactions in the serological diagnosis of toxocariasis by using ELISA and Western blot (WB) assay. For this purpose, sera samples of 209 trichinellosis patients who were definitely diagnosed during the Trichinella britovi outbreak occurred in Izmir in January 2004, were used. All the samples were screened initially by commercial Toxocara IgG-ELISA kit (Cypress Diagnostics, Belgium), then commercial Toxocara IgG-WB (Test-Line Diagnostics, Czech Republic) was applied to positive/borderline-positive sera for confirmation. In our study, 94.3% (197/209) of the sera were found seronegative, while nine were positive and three were borderline. Thus a total of 12 (5.7%) sera were considered as seropositive by Toxocara IgG-ELISA. According to the results of WB, only one sera with the antigenic bands of 120 kDa, 32 kDa and 26 kDa in molecular weights was evaluated as positive. Four sera samples were found to be borderline. In three of border sera, the antigenic bands of 120 and 70 kDa in molecular weights were observed together and one sera had three (120, 70 and 32 kDa) different antigenic bands. Seven sera that had been found to be positive by ELISA was considered as negative by WB. While no bands was observed in four of these, three samples had an antigenic band of 120 kDa which had no diagnostic value when it was found alone. The results of our study showed that the cross-reactivities between anti-Trichinella antibodies and TES antigens may be observed during Toxocara IgG ELISA assay. For that reason the positive Toxocara IgG-ELISA result should be confirmed by different tests such as WB for the definitive diagnosis of toxocariasis