Pneumocystis pneumonia associated with human immunodeficiency virus infection without elevated (1 → 3)-β-D glucan: A case report

Pneumocystis jirovecii detection in asymptomatic patients: what does its natural history tell us?

Pneumocystis jirovecii is an unusual ascomycetous fungus that can be detected in the lungs of healthy individuals. Transmission from human to human is one of its main characteristics in comparison with other fungi responsible for invasive infections. P. jirovecii is transmitted through the air between healthy individuals, who are considered to be the natural reservoir, at least transiently. In immunocompromised patients, P. jirovecii multiplies, leading to subacute infections and acute life-threatening pneumonia, called Pneumocystis pneumonia [PCP]. PCP is caused by genotypically distinct mixtures of organisms in more than 90% of cases, reinforcing the hypothesis that there is constant inhalation of P. jirovecii from different contacts over time, although reactivation of latent organisms from previous exposures may be possible. Detection of P. jirovecii DNA without any symptoms or related radiological signs has been called “colonization”. This situation could be considered as the result of recent exposure to P. jirovecii that could evolve towards PCP, raising the issue of cotrimoxazole prophylaxis for at-risk quantitative polymerase chain reaction (qPCR)-positive immunocompromised patients. The more accurate way to diagnose PCP is the use of real-time quantitative PCR, which prevents amplicon contamination and allows determination of the fungal load that is mandatory to interpret the qPCR results and manage the patient appropriately. The detection of P. jirovecii in respiratory samples of immunocompromised patients should be considered for potential risk of developing PCP. Many challenges still need to be addressed, including a better description of transmission, characterization of organisms present at low level, and prevention of environmental exposure during immunodepression.

Successful treatment of severe Pneumocystis pneumonia in an immunosuppressed patient using caspofungin combined with clindamycin: a case report and literature review

Background

Pneumocystis jirovecii is responsible for Pneumocystis pneumonia (PCP), which occurs almost exclusively in immunocompromised individuals. Trimethoprim-sulfamethoxazole (TMP-SMZ) is regarded as the first-line treatment and prophylaxis for P. jirovecii infection, but the frequency of adverse reactions and newly emerged antibiotic resistance limit its use.

Case presentation

Ulcerations and hemorrhages involving the tongue were noted secondary to TMP-SMZ desensitization against PCP in a 46-year-old male who had previously been diagnosed with IgA nephropathy and sustained prolonged corticosteroid therapy. There was an urgent need for an alternative regimen due to the severe response to TMP-SMZ. The patient was successfully treated with a combination therapy of caspofungin and clindamycin.

Conclusion

Caspofungin combined with clindamycin is an optional treatment for PCP when treatment with TMP-SMZ fails or in patients who cannot tolerate TMP-SMZ.