Cotrimoxazole prophylaxis of Pneumocystis carinii infection during the treatment of childhood acute lymphoblastic leukemia--beware non compliance in older children and adolescents

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.

Pneumocystis jirovecii Pneumonia in Children with Hematological Malignancies: Diagnosis and Approaches to Management

Pneumocystis jirovecii pneumonia (PJP) is an opportunistic infection that mostly affects children with suppressed cellular immunity. PJP was the most common cause of infectious death in children with acute lymphoblastic leukemia prior to the inclusion of cotrimoxazole prophylaxis as part of the standard medical care in the late 1980s. Children with acute leukemia, lymphomas, and those undergoing hematopoietic stem cell transplantation, especially allogeneic transplantation, are also at high risk of PJP. Persistent lymphopenia, graft versus host disease, poor immune reconstitution, and lengthy use of corticosteroids are significant risk factors for PJP. Active infection may be due to reactivation of latent infection or recent acquisition from environmental exposure. Intense hypoxemia and impaired diffusing capacity of the lungs are hallmarks of PJP, while computerized tomography of the lungs is the diagnostic technique of choice. Immunofluorescence testing with monoclonal antibodies followed by fluorescent microscopy and polymerase chain reaction testing of respiratory specimens have emerged as the best diagnostic methods. Measurement of (1-3)-β-D-glucan in the serum has a high negative predictive value in ruling out PJP. Oral cotrimoxazole is effective for prophylaxis, but in intolerant patients, intravenous and aerosolized pentamidine, dapsone, and atovaquone are effective alternatives. Ιntravenous cotrimoxazole is the treatment of choice, but PJP has a high mortality even with appropriate therapy.

Pneumonia After Hematopoietic Stem Cell Transplantation

Pneumonia is the main cause of morbidity and mortality after hematopoietic stem cell transplantation. Two thirds of pneumonias observed after both autologous and allogeneic stem cell transplantations are of infectious origin, and coinfections are frequent. One third is due to noninfectious process, such as alveolar hemorrhage, alveolar proteinosis, or alloimmune pulmonary complications such as bronchiolitis obliterans or idiopathic interstitial pneumonitis. Most of these noninfectious complications may require treatment with corticosteroids which may be deleterious in infection. On the other hand, these complications either mimic or may be complicated with infections. Therefore, a precise diagnosis of pneumonia is of crucial importance to decide of the optimal treatment. CT scan is the best procedure for imaging of the lung. Although several indirect biomarkers, such as serum or plasma galactomannan or (1-3) β(beta)-G-glucan, can help in the etiological diagnosis, only direct invasive investigations provide the best chance to identify the cause(s) of pneumonia. Bronchoalveolar lavage (BAL) under fiberoptic bronchoscopy is the procedure of choice to identify the cause of pulmonary infection. It is safe and reproducible, and its diagnostic yield is around 50 % if the BAL fluid is processed at the laboratory according to a prespecified protocol established between the transplanter, the infectious diseases’ specialist, the pneumologist, and the laboratory, allowing the identification of the most likely hypotheses. Transbronchial biopsy does not provide significant additional information to BAL in most cases and more often complicates with bleeding and pneumothorax. In case of a noncontributory BAL, the decision to proceed to a second BAL, a transthoracic biopsy, or a surgical biopsy should be cautiously weighted in a multidisciplinary approach in regard to the benefits and risks of invasive procedures versus empirical treatment.

Single-day trimethoprim/sulfamethoxazole prophylaxis for Pneumocystis pneumonia in children with cancer

OBJECTIVE

To determine whether a simplified, 1-day/week regimen of trimethoprim/sulfamethoxazole is sufficient to prevent Pneumocystis (jirovecii [carinii]) pneumonia (PCP). Current recommended regimens for prophylaxis against PCP range from daily administration to 3 consecutive days per week dosing.

STUDY DESIGN

A prospective survey of the regimens adopted for the PCP prophylaxis in all patients treated for childhood cancer at pediatric hematology-oncology centers of the Associazione Italiana Ematologia Oncologia Pediatrica.

RESULTS

The 20 centers participating in the study reported a total of 2466 patients, including 1093 with solid tumor and 1373 with leukemia/lymphoma (or primary immunodeficiency; n = 2). Of these patients, 1371 (55.6%) received the 3-day/week prophylaxis regimen, 406 (16.5%) received the 2-day/week regimen, and 689 (27.9%), including 439 with leukemia/lymphoma, received the 1-day/week regimen. Overall, only 2 cases of PCP (0.08%) were reported, both in the 2-day/week group. By intention to treat, the cumulative incidence of PCP at 3 years was 0.09% overall (95% CI, 0.00-0.40%) and 0.51% for the 2-day/week group (95% CI, 0.10%-2.00%). Remarkably, both patients who failed had withdrawn from prophylaxis.

CONCLUSION

A single-day course of prophylaxis with trimethoprim/sulfamethoxazole may be sufficient to prevent PCP in children with cancer undergoing intensive chemotherapy regimens. This simplified strategy might have implications for the emerging need for PCP prophylaxis in other patients subjected to the increased use of biological and nonbiological agents that induce higher levels of immune suppression, such as those with rheumatic diseases.

Antibiotic prophylaxis in children with cancer or who have undergone hematopoietic cell transplantation

Bacterial infections are common in children with cancer and can lead to life-threatening complications. Infections in these patients mainly occur during neutropenic periods, and may be caused by Gram-positive or Gram-negative bacteria. The patients at highest risk of serious infections include those with acute lymphoblastic leukemia (ALL) or acute myeloid leukemia (AML), and those undergoing myeloablative hematopoietic cell transplantation (HCT). This is a review with the main aim of making a critical appraisal of the literature, and summarising what is currently known and can be recommended. The most significant studies support the use of floroquinolones (mainly ciprofloxacin) as the most rational approach to treat pediatric patients with probably long-lasting neutropenia, although trimetoprim-sulphametoxazole and amoxicillin/clavulanate may theoretically be valid alternatives. No prophylaxis seems to be needed for children with cancer without severe neutropenia. However, a global evaluation of the studies of antibiotic prophylaxis in children with cancer indicates that there are not enough data to prepare definite guidelines for its use or avoidance in pediatric oncology, and so further studies are needed. It is not only important to define the best antibiotic regimens for the children in whom such prophylaxis is useful, but also to identify precisely those who do not need it. This would avoid the antibiotic misuse that probably occurs at the moment because many low-risk children with cancer are treated. As prophylaxis against infections requires long-term adherence to an antibiotic regimen, the attitudes and beliefs of stakeholders need to be fully considered.

Compliance with anti-infective preventive measures: A multicentre survey among paediatric oncology patients

BACKGROUND

Infections are significant causes of morbidity and mortality among immunocompromised patients, but little is known about the adherence by the paediatric cancer patients to preventive anti-infective interventions.

METHODS

A voluntary and anonymised questionnaire was distributed to all patients, completing intensive anticancer therapy. Compliance was analysed by using a panel of eight commonly recommended preventive interventions and semi-quantitative scoring of adherence by the patient and/or its caretaker. Satisfaction with information and belief in the efficacy of the interventions were similarly assessed. Relationships of these factors to compliance were explored by using an overall compliance score and non-parametric correlation and/or ANOVA and logistic regression, respectively.

RESULTS

In 216 children and adolescents (mean age: 8 years; 94 girls) included in the study, compliance rates were the highest for food restriction (89.3%), the use of topic antimycotics (88.2%) and trimethoprim/sulfamethoxazole (86.6%), and the lowest for the use of face masks (68.8%), antiseptic mouth rinses (67.1%), non-absorbable antibiotic agents (66.5%) and restrictions in social contacts (65.5%). The most frequent reasons for drug non-compliance were forgetfulness and patient refusal. Compliance correlated with haematological malignancy, younger age and belief in its efficacy, but not with the perceived degree of information, burden of interventions and overall satisfaction with quality of information and medical care.

CONCLUSION

Compliance to recommended anti-infective prophylactic interventions was variable and correlated with haematological malignancy, younger age and belief in efficacy.

Pneumocystis pneumonia in children receiving chemotherapy

Pneumocystis pneumonia (PCP) is a serious complication of chemotherapy-induced immunosuppression. Trimethoprim-sulfamethoxazole (TMP-SMZ) given twice daily, 3 days every week is considered the best form of prophylaxis for PCP. We evaluated PCP prophylaxis in all children up to 18 years of age undergoing cancer chemotherapy over a 2-year period. Four children were diagnosed with PCP over 24 months. Two of 12 children on intravenous pentamidine, 1 of 143 on TMP-SMZ and 1 of 36 on dapsone for PCP prophylaxis developed PCP. Intravenous pentamidine may not be as effective as previously considered and should be used with caution.