Pulmonary infections after renal transplantation: a prospective study from a tropical country

Clinical Features and Prognostic Predictors in Patients with Renal Transplant Complicated by SARS-CoV-2 Infection, a Retrospective Single-Center Study

Background

This study examines the clinical outcomes and prognostic factors of COVID-19 in renal transplant recipients. Given their immunosuppressed status, these patients are at higher risk of severe complications from COVID-19. The study aims to provide healthcare professionals with critical insights for diagnosing and managing this vulnerable population.

Patients and methods

This retrospective cohort study included adult renal transplant recipients diagnosed with COVID-19. Data on demographics, medical history, laboratory results, and patient outcomes were analyzed to identify clinical characteristics and prognostic factors.

Results

This study included 115 renal transplant recipients with COVID-19, predominantly male, with a mortality rate of 10.4% (12 deaths). The overall vaccination rate was 20%. Univariate analysis showed significant differences between survivors and non-survivors in initial serum creatinine levels, and percentages of neutrophils, monocytes, and lymphocytes, along with CRP levels on day 3. Additionally, CRP levels, hemoglobin, and platelet counts on day 7 also differed significantly. Multivariate analysis identified CRP levels on days 3 and 7, day 7 hemoglobin and platelet counts, and concurrent bacterial infections as independent risk factors for mortality.

Conclusion

Elevated CRP levels, renal impairment, and bacterial co-infections play a significant role in the outcomes of COVID-19 in kidney transplant recipients. This study highlights the importance of monitoring these factors for early identification and management of high-risk patients.

Role of Fine Needle Aspiration Cytology in the Rapid Diagnosis of Pulmonary Infections in Renal Allograft Recipients with Respiratory Failure

Background

Renal transplantation is the treatment of choice in patients with end-stage renal disease. However, allograft recipients are at a higher risk of infection due to immunosuppressive therapies. This study aimed to analyze the utility of fine needle aspiration cytology (FNAC) lung in the etiological diagnosis of pulmonary infections in renal allograft recipients with respiratory failure.

Materials and Methods

This is a retrospective study done in post-renal transplant patients presenting with pulmonary infections and respiratory failure in the past 7 years, in whom image-guided lung FNAC was done for diagnosis.

Results

A total of 35 renal allograft recipients presenting with respiratory failure and having focal or diffuse pulmonary opacities (lesions) on radiological imaging were subjected to lung FNAC. The mean age of the patients was 41.1 ± 11.8 years (range 19-72), with the majority being males (n = 28, 80%); six (17.1%) of them were on invasive ventilation. The diagnostic yield of FNAC in our cohort was 77.1% (27 out of 35). Microorganisms were isolated in 21 cases (60%), with Nocardia being the most common (nine cases, 25.7%), Mycobacterial tuberculosis identified in six patients (17.1%), Aspergillus in three (8.6%), and one (2.9%) each had atypical Mycobacterium, zygomycetes, and Cryptococcus. FNAC suggested viral cytopathic effect in five patients, and cytomegalovirus (CMV) quantitative polymerase chain reaction test was found positive in four of these. One case was diagnosed as adenocarcinoma lung.

Conclusion

Lung FNAC is a useful for establishing the etiological diagnosis of pulmonary lesions in renal transplant patients with respiratory failure.

A CRISPR-based nucleic acid detection platform (CRISPR-CPA): application for detection of Nocardia farcinica

AIMS

To establish a CRISPR-based nucleic acid detection platform and apply it to detection of Nocardia farcinica (N. farcinica).

METHODS AND RESULTS

A CRISPR-based nucleic acid detection platform, termed CRISPR-CPA (CRISPR/Cas12a combined with PCR amplification), which employed PCR for pre-amplification of target sequences and CRISPR-Cas12a-based detection for decoding of the PCR amplicons, was developed. To demonstrate its feasibility, CRISPR-CPA was applied to detection of N. farcinica. A pair of PCR primers and a crRNA, which targeting the conservative and specific part of gyrA of N. farcinica reference strain IFM 10152, were designed according to the principle of CRISPR-CPA. The whole detection process of N. farcinica CRISPR-CPA assay, including sample pre-treatment and DNA extraction (~20 min), PCR pre-amplification (60 min), CRISPR-based detection (10 min), can be completed within 90 min. A total of 62 isolates were used to evaluate the specificity of N. farcinica CRISPR-CPA assay. Clinical specimens were employed to determine the feasibility of the method in practical application. The limit of detection of the N. farcinica CRISPR-CPA assay is 1 pg DNA per reaction in pure cultures and 10⁵ CFU/ml in sputum specimens, which is similar with culture but significantly more timesaving.

CONCLUSIONS

The N. farcinica CRISPR-CPA assay is an economic and specific method to detect N. farcinica and provides a high-efficiency tool for screening of pathogens especially of some hard-to-culture and slow-growth infectious agents.

SIGNIFICANCE AND IMPACT OF STUDY

In CRISPR-CPA system, the PCR primers are engineered with a protospacer adjacent motif (PAM) site of Cas12a effector and an additional base A was added at the 5' end of the engineered PCR primer for protecting PAM site, thus the CRISPR-CPA can detect any sequence. Also, we applied CRISPR-CPA to rapidly detect Nocardia farcinica, which is slow-growing bacteria and is firstly detected by a CRISPR-based method.