Prevalence of Pseudomonas aeruginosa and its antibiotic resistance in patients who have received Hematopoietic Stem-Cell Transplantation; A globally Systematic Review.

Gram-negative bacteria are infectious and life-threatening agents after hematopoietic stem cell transplantation (HSCT). So, this study aimed to investigate the prevalence of Pseudomonas aeruginosa and its antibiotic resistance in patients who have received Hematopoietic Stem-Cell Transplantation through a systematic review. The systematic search was done with key words; Pseudomonas aeruginosa, hematopoietic stem cell transplantation from 2000 to the end of July 2023 in Google Scholar and PubMed/Medline, Scopus, and Web of Science. Twelve studies were able to include our study. Quality assessment of studies was done by Appraisal tool for Cross-Sectional Studies. The most of the included studies were conducted as allo-HSCT. Infections such as respiratory infection, urinary infection and bacteremia have occurred. The rate of prevalence with P. aeruginosa has varied between 3 and 100%. The average age of the participants was between 1 and 74 years. The rate of prevalence of P. aeruginosa resistant to several drugs has been reported to be variable, ranging from 20 to 100%. The highest antibiotic resistance was reported against cefotetan (100%), and the lowest was related to tobramycin (1.8%) followed by amikacin, levofloxacin and ciprofloxacin with the prevalence of 16.6%. Our findings showed a high prevalence and antibiotic resistance rate of P. aeruginosa in Hematopoietic stem cell transplantation. Therefore, more serious health measures should be taken in patients after transplantation.

C4d immunohistochemical stain of formalin-fixed paraffin-embedded tissue as a sensitive method in the diagnosis of bullous pemphigoid.

BACKGROUND: Bullous pemphigoid (BP) is the most common type of subepidermal bullous disease. Direct immunofluorescence (DIF) is the gold standard for diagnosis, but it requires a fresh tissue specimen. This study was conducted to evaluate the accuracy of using immunohistochemical (IHC) analysis for the detection of C4d in paraffin-embedded tissue of BP cases. METHODS: A retrospective study was performed on 30 BP cases (confirmed by Hematoxylin and eosin [H&E] and DIF) and 30 controls. IHC studies were performed on formalin-fixed paraffin-embedded (FFPE) tissues. RESULTS: Of 30 BP patients (11 male and 19 female), 27 (90%) were C4d positive and three patients (10%) were C4d negative. The C4d deposits were seen as linear brown stain along the dermoepidermal junction (18 cases), around basal keratinocytes (eight cases), or Civatte-like (three cases). Two cases revealed more than one pattern in IHC staining. Of 30 control specimens, 26 (86%) cases were C4d negative and four (13.4%) were positive for granular deposits of C4d which were diagnosed as dermatitis herpetiformis. CONCLUSION: C4d IHC study is a valuable diagnostic tool with sensitivity of 90% and specificity of 86.7%, and is especially useful in cases in which frozen specimens are not available or FFPE specimens are the only available material for analysis.