In view of the non-specific clinical manifestations of PCP, the diagnosis requires confirmed evidence of pneumocystis carinii, which should not be based on clinical manifestations and imaging even in symptomatic high-risk patients[7].Microscopic identification of ascus and trophic forms is the most intuitive evidence, the diagnostic efficiency is largely determined by the staining method of specimen. Historically, Conventional stains such as Wright’s-Giemsa, hexaamine silver and toluidine blue are available for PCP, but it should be time consuming, also with lower sensitivity[8–10].In this case, immediate diagnosis of PCP was confirmed on the first day of the patient's transfer to ICU with the use of ROSE. Diff-quick has shown its advantage in identifying pneumocystis, characterized by clear structure, sharp contrast, easy identification of ascus (Fig. 3a).
To the best of our knowledge, this is the first report of ROSE used in bedside diagnosis of PCP combined with virtual bronchoscopy (VBN), there is only one previous report described the use of ROSE to diagnose PCP, carried by electromagnetic navigation bronchoscopy guided biopsies[11]. Differently, we used VBN, which can be started quickly at the bedside, and the real-time feedback from ROSE greatly reduces the operation time. But there's a problem, ROSE can be performed by cytotechnologist, pathologist or clinicians. cytotechnologist are the likeliest personnel for ROSE procedure. However, in clinical practice, clinicians replace the role. Study shows alternative evaluators can perform ROSE with acceptable accuracy (a sensitivity of 97% and a specificity of 83%), whereas in wide variation and cannot be generalized[12].Standardized training seems to be needed. Training program could do help to improved the accuracy of adequacy assessment performed by clinicians, and eliminate confounding variables[13].
ROSE is mainly used to increase sampling adequacy for solid malignancies rather than infectious disease. If clinicians can get more useful information from ROSE feedback in infectious disease, it will prompt them to adjust their clinical decisions in a timely manner. Like this medical case, we can easily get diagnostic information from 8 intracapsular bodies under a microscope.
There is no doubt that the diagnostic value of ROSE in infectious diseases must be emphasized. ROSE can be carried out for definite diagnosis, such as PCP. However, many questions remain unclear and need to be solved, such as how to establish a standardized training program of ROSE, which infectious disease can be diagnosed by ROSE and will the ROSE diagnosis provided by clinicians guide clinical practice. More evidence-based studies need to be implemented.