Pulmonary coinfection by Pneumocystis jirovecii and Aspergillus terreus in an ITP patient after corticosteroid therapy: A case report

Pneumocystis jirovecii pneumonia and invasive pulmonary aspergillosis are both life‐threatening opportunistic fungal infections. There are only few reports of coinfection by these two fungi in the literature, and Aspergillus fumigatus is the predominant Aspergillus species in the coinfection. We report here the first case of coinfection by Aspergillus terreus and P. jirovecii pneumonia and caspofungin can be an appropriate choice for salvage treatment of the coinfection. A 51‐year‐old man with a history of immune thrombocytopenia treated with prednisone over 2 months was admitted to emergency intensive care unit for acute respiratory failure and a cavity was found on chest computed tomography. Therefore, his trachea was immediately intubated. The patient was treated with a large spectrum of antibiotic regimen, consisting initially of imipenem/cilastatin, moxifloxacin and fluconazole followed by fluconazole, imipenem/cilastatin, vancomycin, trimethoprim–sulphamethoxazole (TMP‐SMZ) and azithromycin. When the polymerase chain reaction analysis of the bronchoalveolar lavage sample revealed P. jirovecii and A. terreus, all the antibiotics were stopped except TMP‐SMZ, and voriconazole was added. Two weeks later, the patient showed clinical improvement but radiological deterioration. Consequently, caspofungin was started for salvage therapy, then the patient showed gradual clinical improvement. He was discharged with oral voriconazole and TMP‐SMZ. The antifungal treatment was continued for 6 months until complete radiological absorption. In conclusion, early bronchoscopy with bronchoalveolar lavage fluid should be considered in order to diagnose and treat promptly in those treated with corticosteroids combined with immunocompromised and caspofungin could be an appropriate choice for salvage treatment of coinfection by P. jirovecii and A. terreus.

sample revealed P. jirovecii and A. terreus, all the antibiotics were stopped except TMP-SMZ, and voriconazole was added.Two weeks later, the patient showed clinical improvement but radiological deterioration.Consequently, caspofungin was started for salvage therapy, then the patient showed gradual clinical improvement.He was discharged with oral voriconazole and TMP-SMZ.The antifungal treatment was continued for 6 months until complete radiological absorption.In conclusion, early bronchoscopy with bronchoalveolar lavage fluid should be considered in order to diagnose and treat promptly in those treated with corticosteroids combined with immunocompromised and caspofungin could be an appropriate choice for salvage treatment of coinfection by P. jirovecii and A. terreus.

K E Y W O R D S
Aspergillus terreus, caspofungin, ITP, case report, Pneumocystis jirovecii

BACKGROUND
Pneumocystis jirovecii pneumonia (PJP) and invasive pulmonary aspergillosis (IPA) are both life-threatening opportunistic fungal infections.PJP occurs mostly in AIDS patients and is the leading cause of mortality among HIVinfected patients. 1IPA are major complications in non-HIV severely immunocompromised patients and account for high mortality. 2However, the pulmonary coinfection by P. jirovecii and Aspergillus is less frequent, there are only few reports in the literature, [3][4][5][6][7][8][9][10][11][12][13][14][15] and Aspergillus fumigatus is the predominant Aspergillus species in the coinfection.We report a 51-year-old man infected with combined invasive pulmonary Aspergillus terreus and PJP.Trimethoprim-sulphamethoxazole (TMP-SMZ) and voriconazole are the first-line therapies for P. jirovecii and Aspergillus, respectively, but they failed in our case.After combined treatment with caspofungin, the patient showed gradual clinical improvement.

CASE PRESENTATION
A 51-year-old Chinese man with a history of immune thrombocytopenia (ITP) was treated with prednisone 75 mg daily for 1 month, then decreased to 50 mg daily.He was admitted to the emergency with complaints of asthenia, diarrhoea and no urine output and went home after simple rehydration.1A).The patient was admitted to emergency intensive care unit of Ruijin Hospital affiliated to Shanghai Jiao Tong University because of respiratory failure (Figure 2.) The patient's clinical condition worsened within a few hours, and mechanical ventilation was initiated after tracheotomy with metal tracheal tube.Right pneumothorax was observed on day 2, and chest drainage was performed.The patient presented high fever (40 • C), and coarse crackles were audible on both sides on pulmonary auscultation.Empirical treatment with intravenous imipenem/cilastatin (500 mg/6 h), moxifloxacin (400 mg/day) and fluconazole (400 mg/day) was started.
On day 5, the patient was still febrile, his platelet count dropped rapidly from 195 ×10 9 /L to 93 × 10 9 /L.Blood cultures for bacteria and fungus were negative, sputum was repeatedly negative for malignant cells, acid-fast bacilli, aspergillus and candida.Serology for hepatitis B virus, hepatitis C virus, cytomegalovirus, Ebstein-Barr virus, flu virus, herpes simplex 1 and 2, and syphilis was negative.The antibiotic therapy was adjusted, moxifloxacin was stopped, azithromycin (500 mg/day), TMP-SMZ (160-800 mg/8 h) and vancomycin (1000 mg/12 h) were given, imipenem/cilastatin and fluconazole were continued.At the same time, prednisolone (80 mg/day) was initiated.
On day 12, a commercially available multi-pathogen polymerase chain reaction (PCR) assay showed positive signals, targeting the P. jirovecii and A. terreus mitochondrial large subunit rRNA gene in bronchoalveolar lavage fluid (BALF), and both Aspergillus galactomannan and (1,3)-beta-D-glucan (BG) (>1000 pg/mL) were positive in serum.The antibiotics were narrowed to TMP-SMZ and oral voriconazole (200 mg/12 h), which was added subsequently.After adjustment for the treatment, his body temperature dropped to normal and remained stable, but he showed radiological deterioration after 2 weeks.Chest CT (Figure 1B) revealed a multiple cavitary changes, the largest one in the tip of left lung was about 2.5 cm in diameter.The serum BG levels, however, did not decrease, and A. terreus repeatedly found in sputum culture.Consequently, caspofungin (50 mg/day) was added to the combined antibiotic treatment.After 3 weeks treated with caspofungin, CT showed that the diameter of the cavity was reduced to 1.9 cm, both sputum culture and serum BG levels were negative, he was discharged with oral voriconazole and TMP-SMZ.The patient was followed up in the outpatient clinic after discharge, and chest CT (Figure 1C) reviewed in May showed the cavity was almost absorbed.

DISCUSSION AND CONCLUSIONS
We report here the first case of coinfection with A. terreus and P. jirovecii, the reports in the literature were mostly A. fumigatus, and two cases of Aspergillus flavus.A. terreus is not the most frequently occurring human pathogenic Aspergillus species, the overall prevalence of A. terreus accounts for 3%-4% among mold infections. 16However, it does holds an outstanding position among aspergilli due to its high mortality rates and intrinsic resistance against the Amphotericin B (AmB). 17,18TP is an acquired thrombocytopenia caused by the accelerated destruction of platelets and/or suppressed platelet production. 19Corticosteroids are the standard initial treatment for adults with newly diagnosed ITP, 20 and also strongly associated with infections of P. jirovecii.There is no clear evidence linking Aspergillus infection to corticosteroids use.But it seems that the coinfection of Aspergillus and P. jirovecii is closely related to the use of corticosteroids.In the current 14 coinfection case reports, 12 cases had a history of corticosteroids use and the rest two were AIDS patients.The coinfection of Aspergillus and P. jirovecii has a very high mortality rate.Of the 14 cases reported in currently, seven died, with a mortality rate of 50%.The early diagnosis and targeted systemic antifungal treatment are very important for the patient's chances of survival, especially in immunocompromised individuals.
Definitive diagnosis of Aspergillus requires a positive result of culture or direct microscopic examination of fluid and specimens from a normally sterile site, 21 however, lack of a positive culture or direct smear result does not rule out the diagnosis of invasive aspergillosis (IA).Since the culture of sputum and BALF has a low sensitivity, nucleic acid testing, galactomannan, BG, CT scan and bronchoscopy have values to diagnose IA.The diagnosis of PJP was based on the detection of P. jirovecii in respiratory specimens by conventional staining methods.Both BG and PCR are also useful for diagnosis of suspected PJP with BALF. 22Early bronchoscopy with BALF should be considered in order to diagnose the coinfection of PJP and IPA.
Voriconazole and TMP-SMZ remain the preferred agent for treatment of IPA 23 and PJP, 22 respectively.Both voriconazole and TMP-SMZ started orally in our case.Oral voriconazole is recommended in patients with renal dysfunction (creatinine clearance ≤50 mL/min) who should not be exposed to β-cyclodextrin that exists in the intravenous formulation.In non-HIV-infected haematology patients with moderate-to-severe P. jirovecii infection, ECIL-5 recommended TMP-SMZ treatment should be started intravenously at a dosage of 15-20 mg/kg (trimethoprim) and 75-100 mg/kg (sulphamethoxazole), then switch to same dosage in oral once clinically improved. 24owever, intravenous TMP-SMZ is not available in China, so we started with oral TMP-SMZ.For salvage treatment of refractory IA, an additional antifungal agent include lipid formulations of AmB, micafungin, caspofungin, posaconazole or itraconazole may be added to current therapy. 25AmB was excluded in our case due to its intrinsic resistance for A. terreus.Among the rest antifungal agents recommended, caspofungin would be the most appropriate choice because of its therapeutic potential combined with TMP-SMZ for P. jirovecii in vitro and in F I G U R E 2 Timeline of patient main clinical changes and drug therapies.BALF, bronchoalveolar lavage fluid; BG, (1,3)-beta-D-glucan; BP, blood pressure; CRP, C-reactive protein; CT, computed tomography; EICU, emergency intensive care unit; HR, heart rate; ITP, immune thrombocytopenia; PCR, polymerase chain reaction; TMP-SMZ, trimethoprim-sulphamethoxazole; WBC, white blood cell count.
7][28] The duration of the antifungal therapy should be continued for a minimum of 6-12 weeks, depending on immunisation of host and improvement of disease.The antifungal therapy in our case lasted 6 months until the complete radiological absorption (Figure 2).
As medical science progresses in recent years, corticosteroids have been widely used.However, the use of corticosteroids can increase the risk of opportunistic pulmonary infections such as IPA and PJP in the present case.Our case demonstrated that (1) early bronchoscopy with BALF in those treated with corticosteroids combined with immunocompromised should be considered in order to diagnose and treat promptly.(2) For salvage treatment of coinfection by P. jirovecii and A. terreus, caspofungin could be an appropriate choice added to the initial therapy.

A U T H O R C O N T R I B U T I O N S
LLW, DYC and JH conceived and designed this study.FLW, DYC, LYW and YSQ performed the study.YL and JH made substantial contributions to acquisition of data, and involved in drafting the manuscript.LLW and FLW wrote the paper.YL and JH made substantial contributions to general supervision of the research group.GHZ made substantial contributions to acquisition, analysis and interpretation of the data.YL and JH reviewed and revised the manuscript critically for important intellectual content, and approved the final version.All authors read and approved the manuscript.

C O N F L I C T O F I N T E R E S T S TAT E M E N T
The authors declare no conflict of interest.

C O N S E N T T O P U B L I S H
Written informed consent was obtained from the patient to the publication of this case report.A copy of the written informed consent is available for the review by the editor of this journal.

F I G U R E 1
Cavity changes on chest computed tomography (CT).(A) Chest CT on admission, a cavity with diameter of 1.7 cm approximately in the tip of left lung.(B) Chest CT revealed a multiple cavitary changes, the largest one in the tip of left lung was about 2.5 cm in diameter.(C) Chest CT showed the cavity was almost absorbed.
This study was supported by Program for Outstanding Medical Academic Leader of Shanghai.This study was also funded by the Shanghai Shen Kang Hospital Development Center Clinical Science and Technology Innovation Project (No. SHDC12017116), the Important and Weak Discipline Construction Plan for Health and Family Planning System of Shanghai (No. 2016ZB0206), the Biological Medicine Research Program of Shanghai Municipal Science and Technology Commission (No. 12411950500) and the National Natural Science Foundation of China (Nos.81772107 and 81571931).