Therapeutic potential of caspofungin combined with trimethoprim-sulfamethoxazole for pneumocystis pneumonia: a pilot study in mice

A regimen based on the combination of trimethoprim/sulfamethoxazole with caspofungin and corticosteroids as a first-line therapy for patients with severe non-HIV-related pneumocystis jirovecii pneumonia: a retrospective study in a tertiary hospital

BACKGROUND

Pneumocystis jirovecii pneumonia (PJP) is a life-threatening and severe disease in immunocompromised hosts. A synergistic regimen based on the combination of sulfamethoxazole-trimethoprim (SMX-TMP) with caspofungin and glucocorticosteroids (GCSs) may be a potential first-line therapy for PJP. Therefore, it is important to explore the efficacy and safety of this synergistic therapy for treating non-HIV-related PJP patients.

METHODS

We retrospectively analysed the data of 38 patients with non-HIV-related PJP at the First Affiliated Hospital of Xi'an Jiaotong University. Patients were divided into two groups: the synergistic therapy group (ST group, n = 20) and the monotherapy group (MT group, n = 18). All patients were from the ICU and were diagnosed with severe PJP. In the ST group, all patients were treated with SMX-TMP (TMP 15-20 mg/kg per day) combined with caspofungin (70 mg as the loading dose and 50 mg/day as the maintenance dose) and a GCS (methylprednisolone 40-80 mg/day). Patients in the MT group were treated only with SMX-TMP (TMP 15-20 mg/kg per day). The clinical response, adverse events and mortality were compared between the two groups.

RESULTS

The percentage of patients with a positive clinical response in the ST group was significantly greater than that in the MT group (100.00% vs. 66.70%, P = 0.005). The incidence of adverse events in the MT group was greater than that in the ST group (50.00% vs. 15.00%, P = 0.022). Furthermore, the dose of TMP and duration of fever in the ST group were markedly lower than those in the MT group (15.71 mg/kg/day vs. 18.35 mg/kg/day (P = 0.001) and 7.00 days vs. 11.50 days (P = 0.029), respectively). However, there were no significant differences in all-cause mortality or duration of hospital stay between the MT group and the ST group.

CONCLUSIONS

Compared with SMZ/TMP monotherapy, synergistic therapy (SMZ-TMP combined with caspofungin and a GCS) for the treatment of non-HIV-related PJP can increase the clinical response rate, decrease the incidence of adverse events and shorten the duration of fever. These results indicate that synergistic therapy is effective and safe for treating severe non-HIV-related PJP.

Pneumocystis jirovecii Pneumonia after Heart Transplantation: Two Case Reports and a Review of the Literature

Post-transplant Pneumocystis jirovecii pneumonia (PcP) is an uncommon but increasingly reported disease among solid organ transplantation (SOT) recipients, associated with significant morbidity and mortality. Although the introduction of PcP prophylaxis has reduced its overall incidence, its prevalence continues to be high, especially during the second year after transplant, the period following prophylaxis discontinuation. We recently described two cases of PcP occurring more than one year after heart transplantation (HT) in patients who were no longer receiving PcP prophylaxis according to the local protocol. In both cases, the disease was diagnosed following the diagnosis of a viral illness, resulting in a significantly increased risk for PcP. While current heart transplantation guidelines recommend Pneumocystis jirovecii prophylaxis for up to 6-12 months after transplantation, after that period they only suggest an extended prophylaxis regimen in high-risk patients. Recent studies have identified several new risk factors that may be linked to an increased risk of PcP infection, including medication regimens and patient characteristics. Similarly, the indication for PcP prophylaxis in non-HIV patients has been expanded in relation to the introduction of new medications and therapeutic regimens for immune-mediated diseases. In our experience, the first patient was successfully treated with non-invasive ventilation, while the second required tracheal intubation, invasive ventilation, and extracorporeal CO2 removal due to severe respiratory failure. The aim of this double case report is to review the current timing of PcP prophylaxis after HT, the specific potential risk factors for PcP after HT, and the determinants of a prompt diagnosis and therapeutic approach in critically ill patients. We will also present a possible proposal for future investigations on indications for long-term prophylaxis.

Current Concepts in the Diagnosis and Management of Pneumocystis Pneumonia in Solid Organ Transplantation

Pneumocystis infection manifests predominantly as an interstitial pneumonia in immunocompromised patients. Diagnostic testing in the appropriate clinical context can be highly sensitive and specific and involves radiographic imaging, fungal biomarkers, nucleic acid amplification, histopathology, and lung fluid or tissue sampling. Trimethoprim-sulfamethoxazole remains the first-choice agent for treatment and prophylaxis. Investigation continues to promote a deeper understanding of the pathogen's ecology, epidemiology, host susceptibility, and optimal treatment and prevention strategies in solid organ transplant recipients.

Efficacy of Trimethoprim–Sulfamethoxazole in Combination with an Echinocandin as a First-Line Treatment Option for Pneumocystis Pneumonia: A Systematic Review and Meta-Analysis

Although combination therapy using trimethoprim–sulfamethoxazole (TMP–SMX) plus echinocandins has been reported to reduce the mortality of patients with pneumocystis pneumonia (PCP), it remains unclear whether it is more effective than TMP–SMX monotherapy, the current first-line treatment for this disease. Hence, we performed a systematic review and meta-analysis to compare the efficacies of these treatment options for PCP. The Scopus, EMBASE, PubMed, CINAHL, and Ichushi databases were searched for studies (up to January 2022) reporting the mortality and positive response rates (fewer clinical symptoms, improved partial pressure of arterial oxygen, and resolution of pneumonitis on chest imaging) of PCP patients receiving monotherapy or combination therapy. Four studies met the inclusion criteria. All four presented mortality data and one had positive response rates. Compared with the monotherapy, the combination therapy resulted in significantly lower mortality and higher positive response rates (mortality: odds ratio (OR) 2.20, 95% confidence interval (CI) 1.46–3.31; positive response rate: OR 2.13, 95%CI 1.41–3.23), suggesting it to be an effective and promising first-line therapy for PCP. However, further safety evaluations are needed to establish this as a fact.

Single-center retrospective analysis of Pneumocystis jirovecii pneumonia in patients after deceased donor renal transplantation

OBJECTIVE

To investigate the clinical features, early diagnosis, and treatment methods of Pneumocystis jirovecii pneumonia (PJP) after renal transplantation (RT).

METHODS

We retrospectively analyzed the clinical data of 80 patients with confirmed PJP who underwent RT between 2018 and 2021 in our hospital.

RESULTS

In the present study, the incidence of PJP was 6.2% (80/1300). A 50% of cases (40 out of 80 patients) had developed a PJP infection during the first 6 months after RT and 81.3% (65 out of 80 patients) within 12 months. The median onset time of PJP was 6.5 months after RT. The most common symptom was fever (73.8%), followed by progressive dyspnea (51.3%) and dry cough (31.3%). In the initial phase of PJP, the most frequent CT finding was the presence of diffuse ground-grass shadows. In all, 27.5%, 37.5%, and 35% patients were diagnosed by induced sputum metagenomic next-generation sequencing (mNGS), peripheral blood mNGS, and characteristic clinical diagnostic features, respectively. The median 1,3-β-D-glucan level was 500 pg/mL, while the median C-reactive protein level was 63.4 mg/L. In most patients (83.8%), the procalcitonin levels were negative. The mean serum creatinine level was 171.9 ± 87.4 μmol/L. Of the 80 patients, 37 (46.2%) had coexisting cytomegalovirus (CMV) infection. All patients were treated with trimethoprim-sulfamethoxazole and third generation cephalosporin to prevent bacterial infection. The methylprednisolone dose (40-120 mg/d) varied according to illness.

CONCLUSION

PJP usually occurs within 1 year after RT, typically within 6 months. Fever, dry cough, and progressive dyspnea are the most common clinical symptoms. PJP should be highly suspected if the patient has clinical symptoms and diffuse, patchy, ground-glass opacities on CT in both lungs after RT within 1 year. Peripheral blood or induced sputum mNGS is helpful for early diagnosis of PJP. Trimethoprim-sulfamethoxazole is still the first choice for the treatment of PJP. Combined use of caspofungin can reduce the dose and adverse reactions of trimethoprim-sulfamethoxazole in theory.

Case Report: Pneumonia in a Patient With Combined Variable Immunodeficiency: COVID-19 or Pneumocystis Pneumonia?

Combined variable immunodeficiency (CVID) is a primary immunodeficiency, characterized by impairment in immune system function. These patients are susceptible to opportunistic infections, which may mimic COVID-19 manifestations. Also, misdiagnosis or delayed diagnosis of opportunistic infections can lead to perilous consequences. We report a 28-year-old woman with a history of combined variable immunodeficiency disorder (CVID) and ulcerative colitis (UC) complained of fever, cough, and dyspnea. According to the clinical and radiological manifestations and the COVID-19 epidemic, she was admitted with a primary diagnosis of COVID-19 pneumonia. After a week, the patient did not respond to treatment, so she underwent bronchoscopy. Using polymerase chain reaction (PCR) methodology, we detected DNA of Pneumocystis jirovecii, the causative agent of a life-threatening pneumonia (PCP), in respiratory specimens. The patient was hypersensitive to common PCP treatments, so she was treated with high-dose clindamycin. However, the patient's clinical condition aggravated. Besides, we found evidence of pneumothorax, pneumomediastinum, and pneumopericardium in chest CT scan. We inserted a catheter for the patient to evacuate the air inside the mediastinum. Also, we added caspofungin to the treatment. The patient eventually recovered and was discharged from the hospital about a week later. Thus, during the COVID-19 epidemic, in febrile patients with respiratory symptoms, physicians should not think only of COVID-19. They must consider opportunistic infections such as PCP, especially in immunocompromised patients.

Clinical descriptive analysis of severe Pneumocystis jirovecii pneumonia in renal transplantation recipients

Pneumocystis jirovecii (P. jirovecii) pneumonia (PJP) is an opportunistic fungal infection after renal transplantation, which is always severe, difficult to diagnose, combined with multiple complications and have poor prognosis. We retrospectively analyzed clinical data, including risk factors, diagnosis, treatment and complications of seven clinical cases suffered with severe PJP after renal transplantation in our department in 2019. All the seven recipients were routinely prescribed with PJP prophylaxis after renal transplantation, and six of them suffered acute graft rejection before the infection. P. jirovecii sequence was identified in blood or broncho-alveolar lavage fluid (BALF) by the metagenomic next-generation sequencing (mNGS) in all patients. All the patients were improved with the therapy trimethoprim-sulfamethoxazole (TMP-SMX) combined with caspofungin for the PJP treatment, but suffered with complications including renal insufficiency, leukopenia, thrombocytopenia, gastrointestinal bleeding, mediastinalemphysema, pulmonary hemorrhage, and hemophagocytic syndrome and other severe infections. Taken together, mNGS is a powerful tool that could be used to diagnose PJP in renal transplantation recipients. And PJP prophylaxis should be prescribed during and after treatment for acute rejection. TMP-SMX is the first-line and effective drug for PJP treatment, but the complications are always life-threatening and lead to poor prognosis. We should pay attention to these life-threatening complications.

[Clinical problems in Medical Mycology: problem number 55]

A 31-year-old woman, with signs of HIV infection (oral thrush, weight loss, asthenia) presented to our hospital with dyspnea and fever. A rapid HIV test yielded a positive result, and cryptococcal capsular antigen was detected in serum. In the mycological study of the clinical respiratory samples, yeasts compatible with Cryptococcus were observed under light microscope in a wet mount; structures compatible with Pneumocystis jirovecii were also observed in Giemsa stain. Treatment for both pathologies was prescribed but, unfortunately, the patient died 7 days after. The finding of two etiologic agents in the same clinical picture is rare but not exceptional, and it always must be considered in immunocompromised hosts.

Caspofungin combined with TMP/SMZ as a first-line therapy for moderate-to-severe PCP in patients with human immunodeficiency virus infection

OBJECTIVES

The effectiveness of trimethoprim/sulfamethoxazole (TMP/SMZ) for pneumocystis pneumonia (PCP) is limited with adverse events. Caspofungin, by inhibiting the cyst form of Pneumocystis jirovecii, may be an alternative therapy for PCP. However, the availability of clinical data about caspofungin combined with TMP/SMZ in the treatment of PCP in HIV-infected patients is limited. Thus, we aimed to examine the clinical effectiveness and safety of caspofungin combined with TMP/SMZ as a first-line therapy for moderate-to-severe PCP in HIV-infected patients.

METHODS

From January 2017 to December 2019, data of HIV-infected patients with moderate-to-severe PCP who received either TMP/SMZ alone or caspofungin combined with TMP/SMZ as first-line therapy were retrospectively reviewed to assess the effectiveness and safety of each regimen. The Kaplan-Meier curve and log-rank test were used for survival analysis.

RESULTS

A total of 278 patients met the criteria. The overall positive response rate of PCP treatment was 48.92%, and the overall all-cause in-hospital mortality rate was 33.09%. Patients who received combination therapy consisting of caspofungin and TMP/SMZ had a better positive response rate (59.44% vs. 37.78%, P < 0.001) and lower all-cause in-hospital mortality rate (24.48% vs. 42.22%, P = 0.003). Also, patients who received combination therapy had higher survival rate during a hospital stay (75.52% vs. 57.78%, P = 0.004), and those who received longer combination therapy were more likely to have higher survival rate (P = 0.042). We found that age (P = 0.019), CD4 cell count (P = 0.001) and therapeutic regimen (P = 0.002) were significant risk factors for all-cause in-hospital mortality rate in univariate analysis. In multivariate analysis, only CD4 cell count and therapeutic regimen were statistically significant factors associated with all-cause in-hospital mortality rate. Patients with a CD4 count of > 30 cells/µL and patients who received combination therapy consisting of caspofungin and TMP/SMZ were more likely to survive from PCP (P = 0.011 and P = 0.002, respectively). There were no additional severe adverse events caused by adding caspofungin.

CONCLUSIONS

For HIV-infected patients with moderate-to-severe PCP, combination therapy with caspofungin and TMP/SMZ is an effective and promising first-line therapy with no greater number of adverse events compared with TMP/SMZ monotherapy. Patients who received caspofungin had better positive response rates and lower all-cause in-hospital mortality rates. Also, we recommend early initiation of caspofungin.

The early proximal αβ TCR signalosome specifies thymic selection outcome through a quantitative protein interaction network

During αβ T cell development, T cell antigen receptor (TCR) engagement transduces biochemical signals through a protein-protein interaction (PPI) network that dictates dichotomous cell fate decisions. It remains unclear how signal specificity is communicated, instructing either positive selection to advance cell differentiation or death by negative selection. Early signal discrimination might occur by PPI signatures differing qualitatively (customized, unique PPI combinations for each signal), quantitatively (graded amounts of a single PPI series), or kinetically (speed of PPI pathway progression). Using a novel PPI network analysis, we found that early TCR-proximal signals distinguishing positive from negative selection appeared to be primarily quantitative in nature. Furthermore, the signal intensity of this PPI network was used to find an antigen dose that caused a classic negative selection ligand to induce positive selection of conventional αβ T cells, suggesting that the quantity of TCR triggering was sufficient to program selection outcome. Because previous work had suggested that positive selection might involve a qualitatively unique signal through CD3δ, we reexamined the block in positive selection observed in CD3δ⁰ mice. We found that CD3δ⁰ thymocytes were inhibited but capable of signaling positive selection, generating low numbers of MHC-dependent αβ T cells that expressed diverse TCR repertoires and participated in immune responses against infection. We conclude that the major role for CD3δ in positive selection is to quantitatively boost the signal for maximal generation of αβ T cells. Together, these data indicate that a quantitative network signaling mechanism through the early proximal TCR signalosome determines thymic selection outcome.

Anidulafungin as an alternative treatment for Pneumocystis jirovecii pneumonia in patients who cannot tolerate trimethoprim/sulfamethoxazole

Evidence supporting the use of an echinocandin alone as an alternative agent for the treatment of Pneumocystis jirovecii pneumonia (PCP) is limited and controversial. This retrospective cohort study was conducted at National Taiwan University Hospital from 1 July 2015 to 31 December 2017. Using multivariable Cox regression analyses, the outcomes of patients receiving trimethoprim/sulfamethoxazole (TMP-SMZ) or anidulafungin single therapy as an alternative treatment for PCP were investigated. A total of 207 patients with PCP were screened and 170 patients were included in the final analysis, among whom 134 (78.8%) received TMP-SMZ and 36 (21.2%) received anidulafungin as alternative anti-PCP treatment. Overall 60-day mortality was 34.1% (58/170), and 60-day mortality did not differ significantly between the anidulafungin group (38.9%; 14/36) and the TMP-SMZ group (32.8%; 44/134) (P = 0.554). Age ≥60 years [hazard ratio (HR) = 1.840, 95% confidence interval (CI) 1.039-3.259; P = 0.036] and HIV infection (HR = 0.102, 95% CI 0.013-0.771; P = 0.027) independently predicted 60-day mortality. Patients with lower SpO₂/FiO₂ ratio (HR = 0.994, 95% CI 0.990-0.998; P = 0.005) showed a higher 60-day mortality. In the Kaplan-Meier survival analysis, anidulafungin as alternative anti-PCP treatment was not correlated with higher mortality (P = 0.605). Using TMP-SMZ or anidulafungin as alternative anti-PCP treatment had similar 60-day mortality. These findings suggest that anidulafungin therapy may be an effective and alternative treatment for PCP in patients who cannot tolerate TMP-SMZ.

A Pilot Study of Echinocandin Combination with Trimethoprim/Sulfamethoxazole and Clindamycin for the Treatment of AIDS Patients with Pneumocystis Pneumonia

Background and Objectives

Pneumocystis pneumonia (PCP) is a common opportunistic infection in acquired immune deficiency syndrome (AIDS) patients that continues to result in a high mortality rate. To develop a better treatment strategy and improve PCP prognosis, a cohort study was conducted to evaluate the therapeutic potential of echinocandin treatment for AIDS patients with PCP (AIDS-PCP).

Methods

The AIDS-PCP patients were analyzed in our retrospective cohort study that were hospitalized in The First Affiliated Hospital of Zhejiang University during 2013–2018. The antifungal effects of echinocandins were evaluated in two subgroups that were classified by oxygenation as a proxy for the disease state: PaO₂/FiO₂ > 200 mmHg and PaO₂/FiO₂ ≤ 200 mmHg. Intergroup comparisons and survival curves were used to evaluate the effectiveness of the two AIDS-PCP treatment regimens.

Results

During the follow-up, 182 AIDS-PCP patients were diagnosed and analyzed in the study. After excluding 55 patients with other superinfections and five patients that were treated with HAART, the remaining 122 patients were enrolled in the study. The group treated with echinocandins combined with trimethoprim-sulfamethoxazole (TMP-SMZ) and clindamycin exhibited a lower mortality rate (9.62%, 5/52) than did the group with TMP-SMZ and clindamycin treatment (20%, 14/70). For AIDS-PCP patients in the PaO₂/FiO₂ > 200 mmHg subgroup, treatment with echinocandins combined with TMP-SMZ and clindamycin significantly reduced their mortality rate (4.44% (2/45) vs. 18.18% (10/55), P = 0.035).

Conclusion

The results of this study indicate that treatment with echinocandins in combination with the standard TMP-SMZ and clindamycin regimen can improve the prognosis and reduce the mortality rate in patients with mild to moderate AIDS-PCP disease.

High initial (1, 3) Beta-d-Glucan concentration may be a predictor of satisfactory response of c aspofungin combined with TMP/SMZ for HIV-negative patients with moderate to severe Pneumocystis jirovecii pneumonia

OBJECTIVES

The aim of this study was to investigate the efficacy of combination therapy of caspofungin and TMP/SMZ (trimethoprim/sulfamethoxazole) in moderate to severe pneumocystis jirovecii pneumonia (PJP) in patients without human immunodeficiency virus infection (HIV) and the relationship between therapeutic effect and plasma (1, 3) Beta-d-Glucan (BDG) levels.

METHODS

We retrospectively reviewed HIV-negative patients with PJP diagnosed in our department, who were treated with combination therapy of caspofungin and TMP/SMZ or monotherapy of TMP/SMZ during a six and a half year period.

RESULTS

A total of 126 moderate to severe PJP patients were enrolled in the study. In the multivariate analysis, low lymphocyte counts, high serum lactate dehydrogenase levels at the diagnosis of PJP and progression to shock were significant risk factors for death. In all patients, there was no significant difference in risk of death at 3 months. In the group of BDG≥800pg/m, patients receiving combination therapy was associated with a significantly decreased risk of death at 3 months, whereas in the group of BDG<800pg/ml, there were no statistically significant difference in survival rate between the two treatment regimens.

CONCLUSION

High initial plasma (1, 3) Beta-d-Glucan concentration may be a predictor of satisfactory caspofungin response to HIV-negative patients with PJP. Based on our findings, we suggest the choice of combination therapy with caspofungin and TMP/SMZ as the initial treatment when BDG≥800pg/ml in moderate to severe HIV-negative patients with PJP.

Echinocandins as alternative treatment for HIV-infected patients with Pneumocystis pneumonia

OBJECTIVES

Treatment with trimethoprim-sulfamethoxazole for Pneumocystis pneumonia (PCP) is often associated with adverse effects. Echinocandins, by inhibiting the cyst form of Pneumocystis jirovecii, may be an alternative therapy for PCP. However, clinical experience with echinocandins in the treatment of PCP remains limited among HIV-infected patients.

METHODS

From August 2013 to April 2018, data of HIV-infected patients with confirmed PCP who received echinocandins as alternative treatment because of intolerance or unresponsiveness to trimethoprim-sulfamethoxazole were retrospectively reviewed to assess the effectiveness and safety of echinocandins alone or in combination with other agents.

RESULTS

In total, 34 patients were included, with a median CD4 count of 27 cells/μl [interquartile range (IQR), 20-93). Twenty-four patients (70.6%) presented with moderate-to-severe PCP. The most common adverse effects leading to withdrawal of trimethoprim-sulfamethoxazole were hepatotoxicity (29.4%), gastrointestinal upset (23.5%), and rash (17.6%). Nine patients (26.5%) were switched to echinocandins after failure of trimethoprim-sulfamethoxazole. The median interval before switch from trimethoprim-sulfamethoxazole to echinocandins was 9.0 days (IQR 5.0-14.0). The all-cause and PCP-related in-hospital mortality rate of patients receiving echinocandins as alternative therapy was 20.6% (7/34) and 14.7% (5/34), respectively. The all-cause in-hospital mortality was 0% in mild PCP cases and 29% (7/24) in moderate-to-severe PCP cases. Patients who had failed to respond to first-line trimethoprim-sulfamethoxazole treatment tended to have a higher in-hospital mortality rate than those without first-line trimethoprim-sulfamethoxazole failure (44.4% versus 12.0%, P = 0.06).

CONCLUSION

Echinocandin therapy might serve as an alternative option for HIV-infected patients with PCP who are intolerable to trimethoprim-sulfamethoxazole.

Efficacy of caspofungin combined with clindamycin for Pneumocystis jirovecii pneumonia in a systemic lupus erythematosus patient: A case report and literature review

Background

Pneumocystis jirovecii pneumonia (PCP) is an opportunistic infection with a difficult diagnosis, rapid progression, high mortality rate and poor prognosis. The primary treatment and prevention of PCP is trimethoprim/sulfamethoxazole (TMP/SMZ). However, there are many cases of intolerance or resistance to the drug, so the convenient and effective alternatives are deficient.

Case presentation

A 66-year-old woman who took an immunosuppressive agent for a long time was diagnosed with PCP. Poor compliance of treatment was found out after monitoring TMP/SMZ plasma concentrations in this patient. She stopped taking the drug herself because of nausea. As a result of intolerance to TMP/SMZ, caspofungin combined with clindamycin were chosen to continue anti-PCP treatment in this patient. She finally improved and discharged from hospital.

Conclusion

The new combination of caspofungin and clindamycin may be beneficial for patients with PCP who have failed treatment or are intolerant of TMP/SMZ. In addition, the trend of β-glucan levels can be a predictor of therapeutic efficacy in PCP.

Site-Directed Mutagenesis of the 1,3-β-Glucan Synthase Catalytic Subunit of Pneumocystis jirovecii and Susceptibility Assays Suggest Its Sensitivity to Caspofungin

The echinocandin caspofungin inhibits the catalytic subunit Gsc1 of the enzymatic complex synthesizing 1,3-β-glucan, an essential compound of the fungal wall. Studies with rodents showed that caspofungin is effective against Pneumocystis asci. However, its efficacy against asci of Pneumocystis jirovecii, the species infecting exclusively humans, remains controversial. The aim of this study was to assess the sensitivity to caspofungin of the P. jirovecii Gsc1 subunit, as well as of those of Pneumocystis carinii and Pneumocystis murina infecting, respectively, rats and mice. In the absence of an established in vitro culture method for Pneumocystis species, we used functional complementation of the Saccharomyces cerevisiae gsc1 deletant. In the fungal pathogen Candida albicans, mutations leading to amino acid substitutions in Gsc1 confer resistance to caspofungin. We introduced the corresponding mutations into the Pneumocystis gsc1 genes using site-directed mutagenesis. In spot dilution tests, the sensitivity to caspofungin of the complemented strains decreased with the number of mutations introduced, suggesting that the wild-type enzymes are sensitive. The MICs of caspofungin determined by Etest and YeastOne for strains complemented with Pneumocystis enzymes (respectively, 0.125 and 0.12 μg/ml) were identical to those upon complementation with the enzyme of C. albicans, for which caspofungin presents low MICs. However, they were lower than the MICs upon complementation with the enzyme of the resistant species Candida parapsilosis (0.19 and 0.25 μg/ml). Sensitivity levels of Gsc1 enzymes of the three Pneumocystis species were similar. Our results suggest that P. jirovecii is sensitive to caspofungin during infections, as are P. carinii and P. murina.

Prevalence and genotyping of Pneumocystis jirovecii in renal transplant recipients-preliminary report

Pneumocystis jirovecii is an opportunistic fungus occurring in human lungs. The group at highest risk consists of HIV-infected and non-HIV-infected immunosuppressed individuals. In these patients, P. jirovecii infection may lead to Pneumocystis pneumonia; it may, however, persist also in an asymptomatic form. This study aimed to determine the prevalence of P. jirovecii and potential risk factors for infection in a group of renal transplant recipients and to characterize the genetic diversity of this fungus in the studied population. Sputum specimens from 72 patients were tested for presence of P. jirovecii using immunofluorescence microscopy, as well as nested PCR targeting the mtLSU rRNA gene. Genotyping involving analysis of four loci—mtLSU rRNA, CYB, DHPS, and SOD—was used to characterize the diversity of the detected organisms. Pneumocystis DNA was detected in eight (11.11%) patients. It has been shown that low eosinophil count and dual immunosuppressive treatment combining prednisone and calcineurin inhibitors are potential risk factors for colonization. Analysis of genotype distribution showed an association of the wild-type genotype of mtLSU rRNA with lower average age of patients and shorter time after kidney transplantation. Furthermore, CYB 2 genotype was detected only in patients with the ongoing prophylaxis regimen. In conclusion, renal transplant recipients are at risk of Pneumocystis colonization even a long time after transplantation. The present preliminary study identifies specific polymorphisms that appear to be correlated with certain patient characteristics and highlights the need for deeper investigation of these associations in renal transplant recipients.

Echinocandins for Pneumocystis jirovecii pneumonia in non-HIV patients: A case report

For the past two decades, echinocandins have shown prophylactic and therapeutic efficacy in patients with Pneumocystis jirovecii pneumonia (PJP), due to their ability to inhibit the synthesis of β-1, 3-glucan, a major component of the cell wall of P. jirovecii. The present study reported two cases of human immunodeficiency virus (HIV)-negative patients who received echinocandins as a salvage therapy at Peking Union Medical College Hospital (Beijing, China), both of whom exhibited good responses to treatment. In both cases, polymerase chain reaction of sputum or bronchoalveolar lavage specimens became negative following treatment. The present study also performed a literature search to identify non-HIV patients with PJP who previously received echinocandins. The results of the present study suggested that echinocandins maybe promising therapeutic agents in the treatment of non-HIV patients with PJP, particularly in combination with trimethoprim-sulfamethoxazole. Therefore, the results warrant a randomized controlled trial.

A quantitative systems pharmacology (QSP) model for Pneumocystis treatment in mice

BACKGROUND

The yeast-like fungi Pneumocystis, resides in lung alveoli and can cause a lethal infection known as Pneumocystis pneumonia (PCP) in hosts with impaired immune systems. Current therapies for PCP, such as trimethoprim-sulfamethoxazole (TMP-SMX), suffer from significant treatment failures and a multitude of serious side effects. Novel therapeutic approaches (i.e. newly developed drugs or novel combinations of available drugs) are needed to treat this potentially lethal opportunistic infection. Quantitative Systems Pharmacological (QSP) models promise to aid in the development of novel therapies by integrating available pharmacokinetic (PK) and pharmacodynamic (PD) knowledge to predict the effects of new treatment regimens.

RESULTS

In this work, we constructed and independently validated PK modules of a number of drugs with available pharmacokinetic data. Characterized by simple structures and well constrained parameters, these PK modules could serve as a convenient tool to summarize and predict pharmacokinetic profiles. With the currently accepted hypotheses on the life stages of Pneumocystis, we also constructed a PD module to describe the proliferation, transformation, and death of Pneumocystis. By integrating the PK module and the PD module, the QSP model was constrained with observed levels of asci and trophic forms following treatments with multiple drugs. Furthermore, the temporal dynamics of the QSP model were validated with corresponding data.

CONCLUSIONS

We developed and validated a QSP model that integrates available data and promises to facilitate the design of future therapies against PCP.

Caspofungin as Salvage Therapy for Pneumocystis Pneumonia in a Heart Transplant Recipient

Pneumocystis pneumonia (PCP) is a common opportunistic infection in immunocompromised patients. In general, clinical response to therapy with cotrimoxazole is excellent. However, therapy may be limited by side effects or treatment failure. We present a case of PCP in a 35-year-old male patient with history of heart transplantation and renal failure who was admitted with a 10-day history of fever, nonproductive cough and elevated level of creatinine with a diagnosis of PCP confirmed by chest radiography and in bronchoalveolar lavage specimens. He was treated with trimethoprim-sulphamethoxazole (SMZ/TMP) and primaquine but treatment was completed with reduced dosage of cotrimoxazole, primaquine and with the addition of caspofungin. This therapy was effective and without any adverse effects in a patient with elevated level of creatinine.

Echinocandin prophylaxis in patients undergoing haematopoietic cell transplantation and other treatments for haematological malignancies

Antifungal prophylaxis is the standard of care for patients undergoing intensive chemotherapy for haematological malignancy or haematopoietic cell transplantation (HCT). Prophylaxis with azoles reduces invasive fungal infections and may reduce mortality. However, breakthrough infections still occur, and the use of azoles is sometimes complicated by pharmacokinetic variability, drug interactions, adverse events and other issues. Echinocandins are highly active against Candida species, including some organisms resistant to azoles, and have some clinical activity against Aspergillus species as well. Although currently approved echinocandins require daily intravenous administration, the drugs have a favourable safety profile and more predictable pharmacokinetics than mould-active azoles. Clinical data support the efficacy and safety of echinocandins for antifungal prophylaxis in haematology and HCT patients, though data are less robust than for azoles. Notably, sparse evidence exists supporting the use of echinocandins as antifungal prophylaxis for patients with significant graft-versus-host disease (GvHD) after HCT. Two drugs that target (1,3)-β-d-glucan are in development, including an oral glucan synthase inhibitor and an echinocandin with unique pharmacokinetics permitting subcutaneous and weekly administration. Echinocandins are a reasonable alternative to azoles and other agents for antifungal prophylaxis in patients undergoing intensive chemotherapy for haematological malignancy or those receiving HCT, excluding those with significant GvHD.

Efficacy of caspofungin combined with trimethoprim/sulfamethoxazole as first-line therapy to treat non-HIV patients with severe pneumocystis pneumonia

Combined treatment with caspofungin and trimethoprim/sulfamethoxazole (TMP/SMZ) as salvage therapy in non-HIV positive patients with severe pneumocystis pneumonia (PCP) yields poor outcomes. It remains unknown whether the use of this combination strategy as a first-line therapy would improve patient outcomes. The present study aimed to assess the efficacy of caspofungin combined with TMP/SMZ as a first-line therapy in non-HIV positive patients with severe PCP. A retrospective cohort study was conducted between March 2016 and February 2017. Patient clinical characteristics and outcomes were compared between two groups receiving first-line and second-line therapy respectively. In addition, similar cases from previous studies were assessed. A total of 14 patients were included in the present study (mean age, 58.79±14.41 years); including 9 patients receiving caspofungin and TMP/SMZ as a first-line therapy and 5 that received it as a second-line therapy. The overall positive response rate was 71.43% (10/14), with 88.89 (8/9) and 40.00% (2/5) in the first-line and second-line therapy groups, respectively (P=0.095). The positive response rates of patients requiring invasive mechanical ventilation differed significantly between the first-line (5/6, 83.33%) and the second-line (0/3, 0%) therapy groups (P=0.048). All-cause hospital mortality was 42.86% (6/14), with mortality rates of 33.33 (3/9) and 60.00% (3/5) in the first-line and second-line therapy groups, respectively (P=0.580). Combined with previously reported cases (n=27), the positive response rate was significantly greater in the first-line therapy group (11/12, 91.67%) than in the second-line therapy group (8/15, 53.33%, P=0.043). No significant differences were in all-cause mortality rates between the two groups (25.00 vs. 46.67%, P=0.424) were identified, despite the fact that all-course mortality in the first-line therapy group was ~50% that of the second-line therapy group. Therefore, the results of the present study indicate that combined caspofungin and TMP/SMZ as first-line therapy may be a promising and effective strategy to treat non-HIV positive patients with severe PCP, particularly for those requiring invasive mechanical ventilation.

New advances in understanding the host immune response to Pneumocystis

Pneumocystis jirovecii causes clinical pneumonia in immunocompromised hosts. Despite this, the inability to cultivate this organism in vitro has likely hindered the field in ascertaining the true impact of Pneumocystis in human infection. However the recent release of the genome as well as in advances in understanding host genetics, and other risk factors for infection and robust experimental models of disease have shed new light on the impact of this fungal pathogen as to better define populations at risk. This review will highlight these recent advances as well as highlight future needed areas of research.

HIV-related Pneumocystis jirovecii pneumonia managed with caspofungin and veno-venous extracorporeal membrane oxygenation rescue therapy

Patients with pneumocystis pneumonia have a risk of progressing to acute respiratory failure necessitating admission to intensive care. The case described is of a patient with a newly diagnosed HIV infection presenting with pneumocystis pneumonia. Despite initiating the appropriate pharmacological treatment the patient’s clinical condition deteriorated, and required both rescue pharmacological therapy with echinocandins as well as respiratory support with extracorporeal membrane oxygenation therapy. The patient recovered well on ventilator and circulatory support despite a long weaning process complicated by sequelae common to pneumocystis pneumonia. Following initialisation of antiretroviral therapy and step-down from an intensive care setting, the patient required further prolonged hospital stay for rehabilitation and mental health support before being discharged. This case reviews the novel pharmacological therapies and respiratory support strategies used in cases of pneumocystis pneumonia, including the clinical and psychological sequelae that may follow.

Treatment of Pneumocystis jirovecii pneumonia in HIV-infected patients: a review

INTRODUCTION

Pneumocystis pneumonia is a potentially life-threatening pulmonary infection that occurs in immunocompromised individuals and HIV-infected patients with a low CD4 cell count. Trimethoprim-sulfamethoxazole has been used as the first-line agent for treatment, but mutations within dihydropteroate synthase gene render potential resistance to sulfamide. Despite advances of combination antiretroviral therapy (cART), Pneumocystis pneumonia continues to occur in HIV-infected patients with late presentation for cART or virological and immunological failure after receiving cART. Areas covered: This review summarizes the diagnosis and first-line and alternative treatment and prophylaxis for Pneumocystis pneumonia in HIV-infected patients. Articles for this review were identified through searching PubMed. Search terms included: 'Pneumocystis pneumonia', 'Pneumocystis jirovecii pneumonia', 'Pneumocystis carinii pneumonia', 'trimethoprim-sulfamethoxazole', 'primaquine', 'trimetrexate', 'dapsone', 'pentamidine', 'atovaquone', 'echinocandins', 'human immunodeficiency virus infection', 'acquired immunodeficiency syndrome', 'resistance to sulfamide' and combinations of these terms. We limited the search to English language papers that were published between 1981 and March 2017. We screened all identified articles and cross-referenced studies from retrieved articles. Expert commentary: Trimethoprim-sulfamethoxazole will continue to be the first-line agent for Pneumocystis pneumonia given its cost, availability of both oral and parenteral formulations, and effectiveness or efficacy in both treatment and prophylaxis. Whether resistance due to mutations within dihydropteroate synthase gene compromises treatment effectiveness remains controversial. Continued search for effective alternatives with better safety profiles for Pneumocystis pneumonia is warranted.

Characterization of N-Acetylglucosamine Biosynthesis in Pneumocystis species. A New Potential Target for Therapy

N-acetylglucosamine (GlcNAc) serves as an essential structural sugar on the cell surface of organisms. For example, GlcNAc is a major component of bacterial peptidoglycan, it is an important building block of fungal cell walls, including a major constituent of chitin and mannoproteins, and it is also required for extracellular matrix generation by animal cells. Herein, we provide evidence for a uridine diphospho (UDP)-GlcNAc pathway in Pneumocystis species. Using an in silico search of the Pneumocystis jirovecii and P. murina (Pm) genomic databases, we determined the presence of at least four proteins implicated in the Saccharomyces cerevisiae UDP-GlcNAc biosynthetic pathway. These genes, termed GFA1, GNA1, AGM1, and UDP-GlcNAc pyrophosphorylase (UAP1), were either confirmed to be present in the Pneumocystis genomes by PCR, or, in the case of Pm uap1 (Pmuap1), functionally confirmed by direct enzymatic activity assay. Expression analysis using quantitative PCR of Pneumocystis pneumonia in mice demonstrated abundant expression of the Pm uap1 transcript. A GlcNAc-binding recombinant protein and a novel GlcNAc-binding immune detection method both verified the presence of GlcNAc in P. carinii (Pc) lysates. Studies of Pc cell wall fractions using high-performance gas chromatography/mass spectrometry documented the presence of GlcNAc glycosyl residues. Pc was shown to synthesize GlcNAc in vitro. The competitive UDP-GlcNAc substrate synthetic inhibitor, nikkomycin Z, suppressed incorporation of GlcNAc by Pc preparations. Finally, treatment of rats with Pneumocystis pneumonia using nikkomycin Z significantly reduced organism burdens. Taken together, these data support an important role for GlcNAc generation in the cell surface of Pneumocystis organisms.

Identification and Functional Ascertainment of the Pneumocystis jirovecii Potential Drug Targets Gsc1 and Kre6 Involved in Glucan Synthesis

The most efficient drug against the human pathogenic fungus Pneumocystis jirovecii is cotrimoxazole targeting the folate biosynthesis. However, resistance toward it is emerging and adverse effects occur in some patients. Studies in rodent models suggested that echinocandins could be useful to treat Pneumocystis pneumonia. Echinocandins inhibit the catalytic subunit Gsc1 of the enzymatic complex ensuring the synthesis of 1,3-β glucan, an essential constituent of cell walls of most fungi. Besides, inhibitors of the enzyme Kre6 involved in the synthesis of 1,6-β glucan, another essential component of fungal walls, were recently described. We identified and functionally characterized these two potential drug targets in the human pathogen P. jirovecii by rescue of the null allele of the orthologous gene in Saccharomyces cerevisiae. The P. jirovecii proteins Gsc1 and Kre6 identified using those of the relative Pneumocystis carinii as the query sequence showed high sequence identity to the putative fungal orthologs (53-97% in conserved functional domains). The expression of their encoding genes on plasmid rescued the increased sensitivity to, respectively, caspofungin or calcofluor white of the corresponding S. cerevisiae null allele. The uniqueness and likely essentiality of these proteins suggest that they are potential good drug targets.

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.

β-Glucans Are Masked but Contribute to Pulmonary Inflammation During Pneumocystis Pneumonia

β-glucans, which can activate innate immune responses, are a major component in the cell wall of the cyst form of Pneumocystis In the current study, we examined whether β-1,3-glucans are masked by surface proteins in Pneumocystis and what role β-glucans play in Pneumocystis-associated inflammation. For 3 species, including Pneumocystis jirovecii, which causes Pneumocystis pneumonia in humans, Pneumocystis carinii, and Pneumocystis murina, β-1,3-glucans were masked in most organisms, as demonstrated by increased exposure following trypsin treatment. Using quantitative polymerase chain reaction and microarray techniques, we demonstrated in a mouse model of Pneumocystis pneumonia that treatment with caspofungin, an inhibitor of β-1,3-glucan synthesis, for 21 days decreased expression of a broad panel of inflammatory markers, including interferon γ, tumor necrosis factor α, interleukin 1β, interleukin 6, and multiple chemokines/chemokine ligands. Thus, β-glucans in Pneumocystis cysts are largely masked, which likely decreases innate immune activation; this mechanism presumably was developed for interactions with immunocompetent hosts, in whom organism loads are substantially lower. In immunosuppressed hosts with a high organism burden, organism death and release of glucans appears to be an important contributor to deleterious host inflammatory responses.

ECIL guidelines for preventing Pneumocystis jirovecii pneumonia in patients with haematological malignancies and stem cell transplant recipients

The 5th European Conference on Infections in Leukaemia (ECIL-5) meeting aimed to establish evidence-based recommendations for the prophylaxis of Pneumocystis jirovecii pneumonia (PCP) in non-HIV-infected patients with an underlying haematological condition, including allogeneic HSCT recipients. Recommendations were based on the grading system of the IDSA. Trimethoprim/sulfamethoxazole given 2-3 times weekly is the drug of choice for the primary prophylaxis of PCP in adults ( A-II: ) and children ( A-I: ) and should be given during the entire period at risk. Recent data indicate that children may benefit equally from a once-weekly regimen ( B-II: ). All other drugs, including pentamidine, atovaquone and dapsone, are considered second-line alternatives when trimethoprim/sulfamethoxazole is poorly tolerated or contraindicated. The main indications of PCP prophylaxis are ALL, allogeneic HSCT, treatment with alemtuzumab, fludarabine/cyclophosphamide/rituximab combinations, >4 weeks of treatment with corticosteroids and well-defined primary immune deficiencies in children. Additional indications are proposed depending on the treatment regimen.

ECIL guidelines for treatment of Pneumocystis jirovecii pneumonia in non-HIV-infected haematology patients

The initiation of systemic antimicrobial treatment of Pneumocystis jirovecii pneumonia (PCP) is triggered by clinical signs and symptoms, typical radiological and occasionally laboratory findings in patients at risk of this infection. Diagnostic proof by bronchoalveolar lavage should not delay the start of treatment. Most patients with haematological malignancies present with a severe PCP; therefore, antimicrobial therapy should be started intravenously. High-dose trimethoprim/sulfamethoxazole is the treatment of choice. In patients with documented intolerance to this regimen, the preferred alternative is the combination of primaquine plus clindamycin. Treatment success should be first evaluated after 1 week, and in case of clinical non-response, pulmonary CT scan and bronchoalveolar lavage should be repeated to look for secondary or co-infections. Treatment duration typically is 3 weeks and secondary anti-PCP prophylaxis is indicated in all patients thereafter. In patients with critical respiratory failure, non-invasive ventilation is not significantly superior to intubation and mechanical ventilation. The administration of glucocorticoids must be decided on a case-by-case basis.

Pneumocystis jirovecii--from a commensal to pathogen: clinical and diagnostic review

Pneumocystis pneumonia is an opportunistic disease caused by invasion of unicellular fungus Pneumocystis jirovecii. Initially, it was responsible for majority of morbidity and mortality cases among HIV-infected patients, which later have been reduced due to the introduction of anti-retroviral therapy, as well as anti-Pneumocystis prophylaxis among these patients. Pneumocystis pneumonia, however, is still a significant cause of mortality among HIV-negative patients being under immunosuppression caused by different factors, such as transplant recipients as well as oncologically treated ones. The issue of pneumocystosis among these people is particularly emphasized in the article, since rapid onset and fast progression of severe symptoms result in high mortality rate among these patients, who thereby represent the group of highest risk of developing Pneumocystis pneumonia. In contrast, fungal invasion in immunocompetent people usually leads to asymptomatic colonization, which frequent incidence among healthy infants has even suggested the possibility of its association with sudden unexpected infant death syndrome. In the face of emerging strains with different epidemiological profiles resulting from genetic diversity, including drug-resistant genotypes, the colonization phenomenon desires particular attention, discussed in this article. We also summarize specific and sensitive methods, required for detection of Pneumocystis invasion and for distinguish colonization from the disease.

Identification of a New Class of Antifungals Targeting the Synthesis of Fungal Sphingolipids

Recent estimates suggest that >300 million people are afflicted by serious fungal infections worldwide. Current antifungal drugs are static and toxic and/or have a narrow spectrum of activity. Thus, there is an urgent need for the development of new antifungal drugs. The fungal sphingolipid glucosylceramide (GlcCer) is critical in promoting virulence of a variety of human-pathogenic fungi. In this study, we screened a synthetic drug library for compounds that target the synthesis of fungal, but not mammalian, GlcCer and found two compounds [N'-(3-bromo-4-hydroxybenzylidene)-2-methylbenzohydrazide (BHBM) and its derivative, 3-bromo-N'-(3-bromo-4-hydroxybenzylidene) benzohydrazide (D0)] that were highly effective in vitro and in vivo against several pathogenic fungi. BHBM and D0 were well tolerated in animals and are highly synergistic or additive to current antifungals. BHBM and D0 significantly affected fungal cell morphology and resulted in the accumulation of intracellular vesicles. Deep-sequencing analysis of drug-resistant mutants revealed that four protein products, encoded by genes APL5, COS111, MKK1, and STE2, which are involved in vesicular transport and cell cycle progression, are targeted by BHBM.

IMPORTANCE

Fungal infections are a significant cause of morbidity and mortality worldwide. Current antifungal drugs suffer from various drawbacks, including toxicity, drug resistance, and narrow spectrum of activity. In this study, we have demonstrated that pharmaceutical inhibition of fungal glucosylceramide presents a new opportunity to treat cryptococcosis and various other fungal infections. In addition to being effective against pathogenic fungi, the compounds discovered in this study were well tolerated by animals and additive to current antifungals. These findings suggest that these drugs might pave the way for the development of a new class of antifungals.

Efficacy of caspofungin, a 1,3-β-D-glucan synthase inhibitor, on Pneumocystis carinii pneumonia in rats

Pneumocystis carinii pneumonia (PcP) is a common and potentially fatal opportunistic infection in immunosuppressed patients, and the standard trimethoprim-sulfamethoxazole (TMP-SMZ) treatment has serious side effects. The cell wall of the causative fungal pathogen is enriched in 1-3-β-D-glucan, providing an alternative therapeutic target. We directly compared the efficacy of the 1,3-β-D-glucan synthase inhibitor caspofungin to TMP-SMZ for promoting survival and reducing lung cyst number during the early phase of treatment in a rat model of PcP. Rats were immunosuppressed using dexamethasone for 8 weeks and PcP infection confirmed in test animals by lung print smear. The remaining rats were randomly divided into three control groups, a baseline group and two observed for 7 or 14 days, two caspofungin groups treated intravenously for 7 or 14 days (1 mg/kg/d), and 2 TMP-SMZ positive control groups treated by oral gavage for 7 or 14 days (300 mg/kg/d). Mortality was markedly reduced by both caspofungin and TMP-SMZ after 14 days (caspofungin: 20.0%, TMP-SMZ: 13.3%, Control: 40.0%). Body weight gain in caspofungin-treated rats after 7 (3.04 ± 3.54%) and 14 (4.27 ± 2.79%) days was similar to that in TMP-SMZ-treated rats (3.35 ± 1.88% and 5.85 ± 2.78%, respectively), whereas untreated controls showed weight loss. Lung weight to body weight ratio, and mean cyst number per 50 microscopic fields were significantly lower (all P < 0.05) in caspofungin-treated rats than untreated controls at both 7 and 14 days, and similar to those in the TMP-SMZ-treated rats (all P > 0.05 vs. caspofungin). Caspofungin exhibited similar efficacy to TMP-SMZ for enhancing survival and reducing lung edema and cyst load in a rat model of PcP, suggesting potential clinical utility against PcP.

A neglected epidemic: fungal infections in HIV/AIDS

Invasive fungal infections (IFIs) are a major cause of HIV-related mortality globally. Despite widespread rollout of combined antiretroviral therapy, there are still up to 1 million deaths annually from IFIs, accounting for 50% of all AIDS-related death. A historic failure to focus efforts on the IFIs that kill so many HIV patients has led to fundamental flaws in the management of advanced HIV infection. This review, based on the EMBO AIDS-Related Mycoses Workshop in Cape Town in July 2013, summarizes the current state of the-art in AIDS-related mycoses, and the key action points required to improve outcomes from these devastating infections.