Pneumocystis pneumonia in children

Clinical and Radiological Features of Pneumocystis jirovecii Pneumonia in Children: A Case Series

BACKGROUND

Pneumocytis jirovecii pneumonia (PJP) has high mortality rates in immunocompromised children, even though routine prophylaxis has decreased in incidence. The aim of this case series is to present the radiological and clinical pathway of PJP in a pediatric population.

DESCRIPTION OF CASES

All PJP cases in non-HIV/AIDS patients diagnosed at Istituto Giannina Gaslini Pediatric Hospital in Genoa (Italy) from January 2012 until October 2022 were retrospectively evaluated. Nine cases were identified (median age: 8.3 years), and of these, 6/9 underwent prophylaxis with trimethoprim/sulfamethoxazole (TMP/SMX; five once-a-week schedules and one three times-a-week schedule), while 3/9 did not receive this. PJP was diagnosed by real-time PCR for P. jirovecii-DNA in respiratory specimens in 7/9 cases and two consecutive positive detections of β-d-glucan (BDG) in the serum in 2/9 cases. Most patients (6/8) had a CT scan with features suggestive of PJP, while one patient did not undergo a scan. All patients were treated with TMP/SMX after a median time from symptoms onset of 3 days. In 7/9 cases, empirical TMP/SMX treatment was initiated after clinical suspicion and radiological evidence and later confirmed by microbiological data. Clinical improvement with the resolution of respiratory failure and 30-day survival included 100% of the study population.

DISCUSSION

Due to the difficulty in obtaining biopsy specimens, PJP diagnosis is usually considered probable in most cases. Moreover, the severity of the clinical presentation often leads physicians to start TMP/SMX treatment empirically. BDG proved to be a useful tool for diagnosis, and CT showed good accuracy in identifying typical patterns. In our center, single-day/week prophylaxis was ineffective in high-risk patients; the three-day/week schedule would, therefore, seem preferable and, in any case, should be started promptly in all patients who have an indication of pneumonia.

Case Report of COVID-19 and Pneumocystis coinfection in a pediatric patient with a history of receiving high dose steroid therapy

We report the first case of a critically ill pediatric patient coinfected with coronavirus disease 2019 (COVID-19) and Pneumocystis jirovecii pneumonia (PCP). Instances of coinfection of COVID-19 and PCP are being increasingly reported as the COVID-19 pandemic continues. Because the combination can be life-threatening, timely diagnosis and treatment for PCP is necessary in cases where an immunocompromised patient contracts COVID-19.

Molecular Analysis of Dihydropteroate Synthase Gene Mutations in Pneumocystis jirovecii Isolates among Bulgarian Patients with Pneumocystis Pneumonia

Pneumocystis jirovecii pneumonia (PCP) is a significant cause of morbidity and mortality in immunocompromised people. The widespread use of trimethoprim-sulfamethoxazole (TMP-SMZ) for the treatment and prophylaxis of opportunistic infections (including PCP) has led to an increased selection of TMP-SMZ-resistant microorganisms. Sulfa/sulfone resistance has been demonstrated to result from specific point mutations in the DHPS gene. This study aims to investigate the presence of DHPS gene mutations among P. jirovecii isolates from Bulgarian patients with PCP. A total of 326 patients were examined via real-time PCR targeting the P. jirovecii mitochondrial large subunit rRNA gene and further at the DHPS locus. P. jirovecii DNA was detected in 50 (15.34%) specimens. A 370 bp DHPS locus fragment was successfully amplified in 21 samples from 19 PCP-positive patients, which was then purified, sequenced, and used for phylogenetic analysis. Based on the sequencing analysis, all (n = 21) P. jirovecii isolates showed DHPS genotype 1 (the wild type, with the nucleotide sequence ACA CGG CCT at codons 55, 56, and 57, respectively). In conclusion, infections caused by P. jirovecii mutants potentially resistant to sulfonamides are still rare events in Bulgaria. DHPS genotype 1 at codons 55 and 57 is the predominant P. jirovecii strain in the country.

Position statement on infection screening, prophylaxis, and vaccination in pediatric patients with rheumatic diseases and immunosuppressive therapies, part 2: infection prophylaxis

This study aims to provide practical recommendations on prophylaxis for infection in pediatric patients with immune-mediated rheumatic diseases receiving/scheduled to receive immunosuppressive therapy. A qualitative approach was applied. A narrative literature review was performed via Medline. Primary searches were conducted using MeSH terms and free text to identify articles that analyzed data on infections and vaccinations in pediatric patients with immune-mediated rheumatic diseases receiving immunosuppressive therapy. The results were presented and discussed in a nominal group meeting comprising a committee of 12 pediatric rheumatologists from the Prevention and Treatment of Infections Working Group of the Spanish Society of Pediatric Rheumatology. Several recommendations were generated. A consensus procedure was implemented via a Delphi process that was extended to members of the Spanish Society of Pediatric Rheumatology and the Vaccine Advisory Committee of the Spanish Association of Pediatrics. Participants produced a score ranging from 0 (completely disagree) to 10 (completely agree). Agreement was considered to have been reached if at least 70% of participants voted ≥ 7. The literature review included more than 400 articles. Overall, 63 recommendations were generated (23 on infection prophylaxis) and voted by 59 pediatric rheumatologists and other pediatric specialists, all of whom achieved the pre-established level of agreement. The recommendations on prophylaxis of infection cover vaccination and prophylaxis against varicella zoster virus, tuberculosis, Pneumocystis jiroveccii, and invasive fungal infections in pediatric patients with immune-mediated rheumatic diseases receiving/scheduled to receive immunosuppressive therapy.  Conclusion: Based on current evidence and a Delphi process, we provided consensus and updated recommendations on prophylaxis and treatment of infections to guide those caring for pediatric rheumatology patients. What is Known: •Data largely derived from adults find that infectious diseases and related complications are a major cause of morbidity and mortality in patients with immune-mediated rheumatic diseases. •It is crucial to be aware of the preventive measures that should be implemented to prevent these infections in children, although most guidelines are often extrapolated from adult cases. What is New: •In the absence of evidence, a literature review and a Delphi survey were conducted to establish a series of expert recommendations that could prove useful in clinical practice, providing a practical and simple day-to-day approach to be used by pediatric rheumatologists. •The recommendations focus on tuberculosis, herpes zoster virus, fungal infections, and Pneumocystis jirovecii.

Clinical Characteristics and Prognosis of the Modified Probable Pneumocystis jirovecii Pneumonia in Korean Children, 2001-2021

There are few data about Pneumocystis jirovecii pneumonia (PCP) in children, particularly in developed countries. This study investigated the clinical characteristics and prognosis of the clinical PCP in non-HIV-infected Korean children. Children with positive results for the staining and/or polymerase chain reaction (PCR) for P. jirovecii between 2001 and 2021 were identified. Patients were grouped into clinical PCP, which comprised proven and modified probable cases, and non-PCP groups. Modified probable PCP (mp-PCP) indicate the case which P. jirovecii was detected by conventional PCR rather than real-time PCR test. The differences in demographic and clinical characteristics were analyzed between the groups. A total of 110 pneumonia cases with positive results for P. jirovecii PCR and/or stain were identified from 107 children. Of these, 28.2% were classified as non-PCP, 12.7% of proven PCP, and 59.1% of mp-PCP. Compared with the non-PCP group, the mp-PCP group had a significantly higher rate of solid organ transplantation (3.2% vs. 24.6%), fever (58.1% vs. 76.9%), tachypnea (25.8% vs. 66.2%), dyspnea (48.4% vs. 83.1%), desaturation (48.4% vs. 80.0%), and bilateral ground-glass opacity on chest radiograph (19.4% vs. 73.8%). However, when the mp-PCP group was compared with the proven PCP group, there was no statistically significant difference. For children with clinical PCP, age under 5 years of age (odds ratio [OR] 10.7), hospital-onset (OR 6.9), and desaturation as initial symptom (OR 63.5) were significant risk factors for death in multivariable analysis. Modified probable PCP might reliably reflect true PCP in terms of patient's demographic, clinical features, treatment response, and prognosis. Immunocompromised children with hospital-onset pneumonia who are younger than 5 years of age and have desaturation would be more cautiously and aggressively managed for survival through the screening for P. jirovecii by conventional PCR on appropriate lower respiratory specimens.

Clinical-epidemiological characteristics of Pneumocystis jirovecii pneumonia in a tertiary hospital in Spain

INTRODUCTION

HIV infection was the main risk of suffering Pneumocystis jirovecii pneumonia (PJP). The clinical-epidemiological characteristics of PJP have currently changed, with there being few studies on this.

METHODS

A retrospective observational study was carried out on paediatric patients diagnosed with PJP over a 17 year period in a third level hospital in Spain.

RESULTS

A total of 23 patients were included, of whom 7/23 (47.8%) suffered a haematological disease, 5/23 (21.7%) a primary immunodeficiency, and 4/23 (17.4%) an HIV infection. Prophylaxis with trimethoprim-sulfamethoxazole (TMP-SMX) was received by 11/23 (47.8%) patients. All were treated with TMP-SMX and 18/23 (78.3%) with systemic glucocorticoids. There were six (26.1%) deaths, of which one of them (16.7%) suffered an HIV infection. A higher mortality was seen in the non-HIV patients with greater leucocytosis, greater CO2 retention, and a higher heart rate at onset, differences not observed in HIV patients. No differences were found in mortality in relation to the predisposing factor, use of pTMP-SMX, or treatment with glucocorticoids.

CONCLUSIONS

Paediatric patients with haematological cancers are currently the main risk group of developing PJP in this age group. No differences were found in mortality between patients with or without HIV infection as predisposing factor. The mortality among non-HIV patients was higher in those that had greater leucocytosis, greater CO2 retention, and increased heart rate at onset. A better prognosis was not seen in patients that received prophylaxis with TMP-SMX prior to the development of the PJP, or in those that received glucocorticoids as part of the treatment.

Prophylaxis With Trimethoprim/Sulfamethoxazole Is Not Necessary in Children With Solid Tumors Treated With Low-medium Intensity Chemotherapy

Prophylaxis of Pneumocystis jiroveci pneumonia (PJP) with trimethoprim/sulfamethoxazole is a standard of care for children with hematologic malignancies, while its use in solid tumor patients is still debated. A retrospective study focusing on the use of PJP prophylaxis in patients with solid tumors was performed among 16 AIEOP centers: 1046/2863 patients did not receive prophylaxis and no cases of PJP were reported.

Fungal lung disease

Fungal lung disease in the paediatric population occurs with distinct features in the immunocompetent, in immunocompromised patients and in people with cystic fibrosis. Pulmonary mycoses are the least prevalent in immunocompetent children, with the most common diseases being the endemic mycoses and Aspergillomas. Filamentous fungi such as Aspergillus and Scedosporium have been isolated with increased frequency in recent years from the respiratory secretions of individuals with cystic fibrosis. Undoubtedly, fungal respiratory infections are encountered with increased frequency and severity in patients with impaired immune systems, such as patients with malignancies, solid organ or bone marrow transplants and immunodeficiencies [1].

Childhood interstitial lung disease: A case-based review of the imaging findings

Childhood interstitial lung disease (chILD) consists of a large, heterogeneous group of individually rare disorders. chILD demonstrates major differences in disease etiology, natural history, and management when compared with the adult group. It occurs primarily secondary to an underlying developmental or genetic abnormality affecting the growth and maturity of the pediatric lung. They present with different clinical, radiologic, and pathologic features. In this pictorial review article, we will divide chILD into those more prevalent in infancy and those not specific to infancy. We will use a case based approach to discuss relevant imaging findings including modalities such as radiograph and computed tomography in a wide variety of pathologies.

Recent epidemiology of Pneumocystis pneumonia in Japan

OBJECTIVES

The objective of this study was to describe the recent epidemiology of Pneumocystis pneumonia (PCP) in Japan using a nationwide database.

METHODS

We extracted data of inpatients with PCP from the Diagnostic Procedure Combination database, a national inpatient database in Japan, from January 2010 to December 2016.

RESULTS

During the study period, 4293 PCP patients were identified, including 4073 adults and 220 children. In adults, the most common comorbidity was hematologic malignancy (31%), followed by diabetes mellitus (30%), rheumatic/collagen diseases (26%), and solid organ tumors (18%). In children, there were few patients with rheumatic diseases (5%) or diabetes mellitus (2%), but immunodeficiency (without human immunodeficiency virus) was more common (28%). Few biological products were used for adult and pediatric patients; CD20 inhibitors, TNF-α inhibitors, interleukin receptor inhibitors, and CTLA-4 inhibitor were used for 8.6% and 2.4%, 1.3% and 0%, 1.2% and 4.7%, and 0.2% and 0% of adult and pediatric patients, respectively. Based on data stratified by bed count, the annual numbers of PCP patients in Japan were estimated as 2221 adults and 123 pediatric patients. The mortality was higher in adults (27%) than in pediatric patients (21%) (P = 0.041).

CONCLUSIONS

The underlying disease and mortality were apparently different between adult and pediatric PCP patients.

A Novel GNAS Mutation Causing Isolated Infantile Cushing's Syndrome

Infantile Cushing's syndrome is potentially found as part of McCune-Albright syndrome (MAS) which is caused by postzygotic somatic mutations of the GNAS gene. MAS is typically characterized by a triad of polyostotic fibrous dysplasia, café-au-lait skin pigmentation, and precocious puberty or other endocrine hyperfunction. Here, we describe a 2-month-old female infant with features of Cushing's syndrome without café au lait spots, polyostotic fibrous dysplasia, and clinical evidence of other endocrine hyperfunction. Investigations demonstrated adrenocorticotropic hormone-independent Cushing's syndrome with bilateral adrenal gland enlargement. Whole-exome sequencing of leukocytes identified a de novo heterozygous novel missense mutation (c.521G>A, p.Cys174Tyr) in the GNAS gene. The patient experienced clinical improvement of Cushing's syndrome during ketoconazole treatment. Her clinical course was complicated by Pneumocystis jiroveci pneumonia. She also had shortened activated partial thromboplastin time indicating a hypercoagulable state and resulting in pulmonary embolism. She eventually manifested gonadotropin-independent precocious puberty at the age of 13 months after ketoco-nazole was discontinued. This patient demonstrated that Cushing syndrome can be the presenting sign of MAS in infancy. A high index of suspicion followed by genetic analysis is essential in order to establish a diagnosis.

Diagnosis of Pneumocystis jirovecii Pneumonia in Pediatric Patients in Serbia, Greece, and Romania. Current Status and Challenges for Collaboration

Pneumocystis jirovecii can cause fatal Pneumocystis pneumonia (PcP). Many children have been exposed to the fungus and are colonized in early age, while some individuals at high risk for fungal infections may develop PcP, a disease that is difficult to diagnose. Insufficient laboratory availability, lack of knowledge, and local epidemiology gaps make the problem more serious. Traditionally, the diagnosis is based on microscopic visualization of Pneumocystis in respiratory specimens. The molecular diagnosis is important but not widely used. The aim of this study was to collect initial indicative data from Serbia, Greece, and Romania concerning pediatric patients with suspected PcP in order to: find the key underlying diseases, determine current clinical and laboratory practices, and try to propose an integrative future molecular perspective based on regional collaboration. Data were collected by the search of literature and the use of an online questionnaire, filled by relevant scientists specialized in the field. All three countries presented similar clinical practices in terms of PcP prophylaxis and clinical suspicion. In Serbia and Greece the hematology/oncology diseases are the main risks, while in Romania HIV infection is an additional risk. Molecular diagnosis is available only in Greece. PcP seems to be under-diagnosed and regional collaboration in the field of laboratory diagnosis with an emphasis on molecular approaches may help to cover the gaps and improve the practices.

Acquired Immunodeficiency from Maternal Chemotherapy and Severe Primary Pneumocystis Infection in an Infant

Pneumocystis jirovecii is recognized as an opportunistic pathogen in immunosuppressed patients. We report a case of severe Pneumocystis pneumonia (PCP) in an infant with acquired combined immunodeficiency secondary to maternal chemotherapy exposure during the second and third trimesters of pregnancy. The infant required cardiorespiratory support with veno-venous extracorporeal membrane oxygenation (VV-ECMO) for severe respiratory failure. This case highlights the potential for severe acquired immunodeficiency in this patient cohort and further postnatal surveillance is highly recommended.

Two pediatric cases of Pneumocystis jirovecii pneumonia diagnosed by polymerase chain reaction of gastric lavage

Detecting Pneumocystis jirovecii by bronchoalveolar lavage or lung biopsy is the gold standard for diagnosis of P. jirovecii pneumonia (PJP); however, these techniques are not always applicable in children because of their high invasiveness. We report two pediatric cases of PJP diagnosed by polymerase chain reaction (PCR) of gastric lavage that were successfully treated. To date, there are no reported cases of using PCR of gastric lavage to diagnose PJP. On the day of PJP onset, both the infants required respiratory support and infiltrative shadows were observed in both lung fields on chest radiography. Furthermore, their (1 → 3)-β-D glucan levels were elevated. P. jirovecii was detected by PCR of gastric lavage and trimethoprim-sulfamethoxazole was administered for 3 weeks, following which their condition improved. They were long-term steroid users, but without any prophylaxis. PCR of gastric lavage in cases of suspected PJP may help in confirming the diagnosis in children who have mild to moderate airway symptoms, or have difficulty with invasive examination like bronchoscopy.

Life-Threatening Hypercalcemia During Prodrome of Pneumocystis jiroveci Pneumonia in an Immunocompetent Infant

Severe hypercalcemia in infants is usually attributed to genetic etiologies and less commonly to acquired ones. An 8-week-old girl presented with failure to thrive, mild respiratory distress, and life-threatening hypercalcemia (23.5 mg/dL). Serum 1,25(OH)₂-vitamin D (1,25(OH)₂-D) level was elevated and parathyroid hormone undetectable. Evaluation for genetic mutations and malignant etiologies of hypercalcemia was negative. Treatment with intravenous hydration, loop diuretic, and calcitonin failed to correct the hypercalcemia, which was subsequently controlled with bisphosphonate therapy. Due to progressive respiratory deterioration, a bronchopulmonary lavage was done on day 17 of her hospitalization disclosing Pneumocystis jiroveci infection. The subsequent immunological investigation showed no abnormalities. She was treated with trimethoprim/sulfamethoxazole resulting in gradual clearing of her lungs and normalization of serum 1,25(OH)₂-D level. A year later, she remains healthy with normal biochemical parameters of mineral metabolism. We conclude that in a child with hypercalcemia with suppressed parathyroid hormone and elevated 1,25(OH)₂-D, once the genetic etiology for elevated 1,25(OH)₂-D and malignancy are ruled out, one should investigate closely for a chronic granulomatous disease. Among the latter Pneumocystis jiroveci pneumonia infection should be considered even in an immunocompetent child.

Early use of corticosteroids in infants with a clinical diagnosis of Pneumocystis jiroveci pneumonia in Malawi: a double-blind, randomised clinical trial

BACKGROUND

Pneumocystis jiroveci pneumonia (PJP) is the most common opportunistic infection in infants with vertically acquired HIV infection and the most common cause of death in HIV-infected infants.

OBJECTIVES

To determine whether early administration of adjuvant corticosteroids in addition to standard treatment reduces mortality in infants with vertically acquired HIV and clinically diagnosed PJP when co-infection with cytomegalovirus and other pathogens cannot be excluded.

METHODS

A double-blind placebo-controlled trial of adjuvant prednisolone treatment in HIV-exposed infants aged 2-6 months admitted to Queen Elizabeth Central Hospital, Blantyre who were diagnosed clinically with PJP was performed. All recruited infants were HIV-exposed, and the HIV status of the infant was confirmed by DNA-PCR. HIV-exposed and infected infants as well as HIV-exposed but non-infected infants were included in the study. The protocol provided for the addition of prednisolone to the treatment at 48 h if there was clinical deterioration or an independent indication for corticosteroid therapy in any patient not receiving it. Oral trimethoprim-sulfamethoxazole (TMP/SMX) therapy and full supportive treatment were provided according to established guidelines. Primary outcomes for all patients included survival to hospital discharge and 6-month post-discharge survival.

RESULTS

It was planned to enroll 200 patients but the trial was stopped early because of recruitment difficulties and a statistically significant result on interim analysis. Seventy-eight infants were enrolled between April 2012 and August 2014; 36 infants (46%) were randomised to receive corticosteroids plus standard treatment with TMP/SMX, and 42 infants (54%) received the standard treatment plus placebo. In an intention-to treat-analysis, the risk ratio of in-hospital mortality in the steroid group compared with the standard treatment plus placebo group was 0.53 [95% CI 0.29-0.97, p = 0.038]. The risk ratio of mortality at 6 months was 0.63 (95% CI 0.41-0.95, p = 0.029). Two children who received steroids developed bloody stools while in hospital.

CONCLUSION

In infants with a clinical diagnosis of PJP, early use of steroids in addition to conventional TMP/SMX therapy significantly reduced mortality in hospital and 6 months after discharge.

Efficacy and Safety of Dapsone Versus Trimethoprim/Sulfamethoxazol for Pneumocystis Jiroveci Prophylaxis in Children With Acute Lymphoblastic Leukemia With a Background of Ethnic Neutropenia

STUDY OBJECTIVE

To study dapsone in comparison with trimethoprim/sulfamethoxazole (TMP/SMX) for Pneumocystis jiroveci (PJP) prophylaxis in children with acute lymphoblastic leukemia (ALL).

DESIGN

A retrospective study with a prospective follow-up.

PATIENTS

Pediatric ALL patients diagnosed between May 2009 and May 2014, who are still receiving or have completed their maintenance chemotherapy. Patients who completed chemotherapy were prospectively followed up for neutropenia.

METHODS

TMP/SMX was used as the initial PJP prophylaxis. An alternative drug was indicated if the patient remained cytopenic for >3 weeks. Average absolute neutrophilic count (ANC), average % of oral mercaptopurine (6-MP), and methotrexate doses were calculated over a period of 6 months before and after shifting to dapsone.

RESULTS

Sixty-two ALL patients were eligible for analysis. Twenty-four patients (38.7%) received TMP/SMX for PJP prophylaxis, whereas 34 patients received Dapsone (54.8%). Only 3 patients received IV pentamidine (4.8%), whereas 1 patient (1.6%) received atovaquone. The incidence of prophylaxis failure was 1/1041 months on TMP/SMX and 1/528 months on dapsone. After shifting to dapsone, patients maintained significantly higher ANC (1.46±0.46 vs. 1.17±0.40, P=0.0053), and received significantly higher doses of 6-MP (62.61%±11.45 vs. 57.45±10.14, P=0.0081) and methotrexate (64.9%±14.29 vs. 56.5%±9.9, P=0.0176), with a significantly shorter duration of chemotherapy interruption (1.94±1.2 vs. 3.25±1.29 wk, P=0.0002).

CONCLUSIONS

Dapsone for PJP prophylaxis in ALL allowed patients to maintain higher ANC and to receive higher doses of chemotherapy, while maintaining a low incidence of PJP breakthrough infection.

Pneumocystis jirovecii-induced chronic interstitial lung disease in Waldenström's macroglobulinemia

Infections with Pneumocystis jirovecii can result in asymptomatic colonization or induce life threatening clinical symptoms. However, there appears to be a 'gray area' between colonization and severe pneumonia that remains underestimated so far. We describe a case with chronic interstitial lung disease and chronic cough that was attributed to P. jirovecii. The patient's history of chronic cough, although very likely being fostered by the underlying Waldenström's macroglobulinemia and interstitial lung disease, was most likely caused by P. jirovecii infection. This gives raise to the hypothesis that P. jirovecii infections do not necessarily induce life threatening pneumonia. Consequently, serial testing is required in eligible patients with positive PCR results in order to discriminate between colonization, 'gray zone' infection, and beginning pneumonia.

Pneumocystis jirovecii Pneumonia in Pediatric Inflammatory Bowel Disease: A Case Report and Literature Review

Immunosuppressive therapy is a known risk factor for opportunistic infections. We report the first case of severe Pneumocystis jirovecii infection requiring intensive care in a pediatric patient with inflammatory bowel disease (IBD). The literature was reviewed and there were 92 reported cases of Pneumocystis pneumonia (PCP) in patients with IBD. Most sources were case reports and there was likely reporting bias toward patients receiving immunomodulators, anti-tumor necrosis factor (anti-TNF) therapy, and those who died. Overall, 56% of patients were males and 58% had Crohn's disease. The median age was 45 years (interquartile range 30-68, range 8-78) and 86% of patients were lymphopenic. The case-fatality rate was 23%. Corticosteroids were used as IBD treatment in 88% of patients who subsequently developed PCP, 42% received thiopurines, 44% used anti-TNF therapy, and 15% received either cyclosporine or tacrolimus. Rates of mono, dual, triple, and quadruple immunosuppression therapy were 35, 35, 29, and 2%, respectively. This report highlights the importance of considering PCP in immunosuppressed lymphopenic pediatric IBD patients who present with unusual symptoms. Moreover, it should give gastroenterologists the impetus to limit immunosuppressive therapy to its minimal effective dose and consider options such as exclusive enteral nutrition wherever possible. Although there is no place for global PCP prophylaxis in IBD given the low incidence, in an era when there is increasing use of biologic agents with combination immunosuppressive therapy, the risk-benefit profile of PCP chemoprophylaxis should be revisited in selected cohorts such as patients on triple immunosuppression with corticosteroids, thiopurines, and a biological agent or calcineurin inhibitor, especially in lymphopenic individuals.

Safety and Effectiveness of Intravenous Pentamidine for Prophylaxis of Pneumocystis jirovecii Pneumonia in Pediatric Hematology/Oncology Patients

BACKGROUND

Pneumocystis jirovecii pneumonia (PCP) is an opportunistic infection that can lead to significant morbidity and mortality in immunocompromised pediatric hematology/oncology patients. Trimethoprim/sulfamethoxazole is the gold standard for prophylaxis. Intravenous (IV) pentamidine is the preferred second-line agent for PCP prophylaxis at our institution and is used first-line under certain circumstances. The purpose of this study is to evaluate the effectiveness and safety of IV pentamidine for PCP prophylaxis in pediatric hematology/oncology patients.

MATERIALS AND METHODS

A retrospective analysis of pediatric hematology/oncology patients (N=121) who received ≥1 dose of IV pentamidine between January 2009 and July 2014 was conducted. Electronic health records were reviewed to determine baseline characteristics, rate of breakthrough PCP infection, characteristics of IV pentamidine use, and adverse events. The follow-up period was 6 months after the last reported IV pentamidine dose or the last recorded clinic visit/hospital admission.

RESULTS

No patients developed PCP during the entirety of their IV pentamidine course or during the follow-up period. Nineteen patients (16%) experienced adverse events and 5 of the 19 patients required discontinuation of IV pentamidine.

CONCLUSIONS

IV pentamidine is a safe, tolerable, and effective agent for PCP prophylaxis in pediatric hematology/oncology patients and may be considered a reasonable therapeutic alternative when trimethoprim/sulfamethoxazole cannot be used for PCP prophylaxis.

Surveillance of bloodstream infections in pediatric cancer centers - what have we learned and how do we move on?

Pediatric patients receiving conventional chemotherapy for malignant disease face an increased risk of bloodstream infection (BSI). Since BSI may represent an acute life-threatening event in patients with profound immunosuppression, and show further negative impact on quality of life and anticancer treatment, the prevention of BSI is of paramount importance to improve and guarantee patients' safety during intensive treatment. The great majority of all pediatric cancer patients (about 85%) have a long-term central venous access catheter in use (type Broviac or Port; CVAD). Referring to the current surveillance definitions a significant proportion of all BSI in pediatric patients with febrile neutropenia is categorized as CVAD-associated BSI. This state of the art review summarizes the epidemiology and the distinct pathogen profile of BSI in pediatric cancer patients from the perspective of infection surveillance. Problems in executing the current surveillance definition in this patient population are discussed and a new concept for the surveillance of BSI in pediatric cancer patients is outlined.

Pneumocystis jirovecii pneumonia: still a concern in patients with haematological malignancies and stem cell transplant recipients

The risk of patients with ALL and recipients of an allogeneic HSCT developing Pneumocystis jirovecii pneumonia is sufficiently high to warrant guidelines for the laboratory diagnosis, prevention and treatment of the disease. In this issue, the European Conference on Infections in Leukemia (ECIL) presents its recommendations in three companion papers.

Pneumocystis pneumonia in non-HIV children: a 10-year retrospective study

BACKGROUND

Pneumocytis pneumonia (PCP) is a life-threatening disease in non-HIV infected children. However, there have been few studies that have examined the clinical characteristics associated with PCP and outcomes for these pediatric patients.

OBJECTIVES

A retrospective review was performed over a 10-year period to evaluate the clinical characteristics and outcome of non-HIV children diagnosed with PCP at Beijing Children's Hospital in China.

RESULTS

A total of 60 non-HIV children diagnosed with PCP were included in the study. The overall mortality was 41.7% (25/60). Underlying diseases included connective tissue disease (n = 23; 38.3%), hematological disease (n = 14; 23.3%), nephrotic disease (n = 8; 13.3%) and immunodeficiency disease (n = 10; 16.7%). In all, 26/40 (65.0%) children developed PCP after receiving a follow-up large dose of glucocorticoid because of recurrent disease. Median time from beginning glucocorticoid medication to PCP diagnosis was 245.9 days (range: 14-2100 days). The area under the ROC curve of CD4/CD8 T cell levels for the diagnosis of PCP was 0.902 (95% confidence interval, 0.849-0.955). The analysis rendered an optimum cut-off value of 0.715 corresponding to 89.2% sensitivity and 80.4% specificity. Using a multivariate logistic regression model, three parameters were identified as significantly associated with mortality: LDH level, mechanical ventilation and co-infection.

CONCLUSION

The outcome of PCP in non-HIV children remains poor. A critical stage for PCP development is administration of follow-up glucocorticoid without prophylaxis. CD4/CD8 ratio is a suitable biomarker for predicting PCP and diagnostic of PCP in non-HIV children. Poor prognostic factors include LDH level, need for mechanical ventilation and co-infection.

Safe and Effective Prophylaxis with Bimonthly Intravenous Pentamidine in the Pediatric Hematopoietic Stem Cell Transplant Population

BACKGROUND

Without prophylaxis, Pneumocystis jiroveci pneumonia (PCP) develops in 5%-15% of pediatric hematopoietic stem cell transplant (HCT) patients with mortality above 50%. Trimethoprim-sulfamethoxazole is a standard PCP prophylaxis; pentamidine is frequently used as second-line prophylaxis because of trimethoprim-sulfamethoxazole's potential for cytopenias. Monthly intravenous (IV) pentamidine has variable efficacy with PCP infection rates of 0%-10% in pediatric patients, and higher breakthrough rates in those younger than 2 years. We hypothesized that bimonthly (twice monthly) pentamidine might have equivalent safety and improved efficacy; therefore, we conducted a retrospective analysis of bimonthly pentamidine PCP prophylaxis.

METHODS

We retrospectively reviewed records of all pediatric HCT patients who received bimonthly IV pentamidine between December 2006 and June 2013, and collected data regarding demographics, clinical course, prophylaxis rationale, laboratory values and adverse events.

RESULTS

Between December 2006 and June 2013, 111 pediatric HCT patients received bimonthly IV pentamidine (574 doses, 8758 patient-days); 31 patients were younger than 2 years at initiation. In the majority (53% of courses), pentamidine was initiated because of cytopenias. Fourteen patients (12.6% of patients, 2.4% of doses) experienced a side-effect prompting discontinuation, including 3 patients with infusion-related hypotension/anaphylaxis and 3 with acute pancreatic dysfunction. No patients [0% (95% confidence interval: 0-3.2)] developed PCP during or after bimonthly IV pentamidine prophylaxis.

CONCLUSIONS

Bimonthly IV pentamidine for PCP prophylaxis in the HCT pediatric population has comparable safety to monthly IV pentamidine and was highly effective, including in the very young. Bimonthly IV pentamidine should be considered in pediatric patients as second-line PCP prophylaxis.

Analysis of current antifungal agents and their targets within the Pneumocystis carinii genome

Pneumocystis pneumonia (PCP) remains a leading opportunistic infection in patients with weakened immune systems. The fungus causing the infection belongs to the genus, Pneumocystis, and its members are found in a large variety of mammals. Adaptation to the lung environment of a host with an intact immune system has been a key to its successful survival. Unfortunately, the metabolic strategies used by these fungi to grow and survive in this context are largely unknown. There were considerable impediments to standard approaches for investigation of this unique pathogen, the most problematic being the lack of a long term in vitro culture system. The absence of an ex vivo cultivation method remains today, and many fundamental scientific questions about the basic biology, metabolism, and life cycle of Pneumocystis are unanswered. Recent progress in sequencing of the Pneumocystis carinii genome, a species infecting rats, permitted a more informative search for genes and biological pathways within this pathogen that are known to be targets for existing antifungal agents. In this work, we review the classes of antifungal drugs with respect to their potential applicability to the treatment of PCP. Classes covered in the review are the azoles, polyenes, allylamines, and echinocandins. Factors limiting the use of standard antifungal treatments and the currently available alternatives (trimethoprim-sulfamethoxazole, atovaquone, and pentamidine) are discussed. A summary of genomic sequences within Pneumocystis carinii associated with the corresponding targeted biological pathways is provided. All sequences are available via the Pneumocystis Genome Project at http://pgp.cchmc.org/.

Pneumocystis carinii Pneumonia Prophylaxis

Pneumocystis pneumonia (PCP) can be life threatening for children receiving chemotherapy and immunosuppressive medication, including high-dose steroids. Although there are no current guidelines for prophylaxis in pediatric oncology patients, ongoing studies are evaluating the efficacy, side effects, ease of administration, and compliance of drugs used for PCP prophylaxis. Drugs currently being prescribed in practice include Bactrim, pentamidine, dapsone, and atovaquone. Bactrim remains superior for preventing PCP, but alternatives are being analyzed and investigated for those unable to tolerate Bactrim because of drug allergy or side effects. Educating patients and families about the importance of PCP prophylaxis and compliance should be a priority for all health care providers caring for children receiving immunosuppressive medications, including chemotherapy.