Immunosuppressed

Question 1

What are the types of congenital defects that can lead to immunocompromised pediatric patients?

Answer 1

Defects of innate host defenses, neutrophil abnormalities, defects affecting lymphocyte function, defects of humoral immunity

These defects increase susceptibility to infections.

Question 2

What is a common characteristic of pulmonary infections in immunocompromised children?

Answer 2

Often nonspecific clinical presentation

Atypical or opportunistic pathogens require a high index of suspicion.

Question 3

What are the two components of the immune system involved in disorders of the immune system?

Answer 3

Innate component, adaptive component

Both components contribute to the overall immune response.

Question 4

What are the phases of immune recovery after myeloablative conditioning followed by HSCT?

Answer 4

Preengraftment phase, postengraftment phase, late phase

Each phase has different characteristics regarding immune recovery.

Question 5

Which viral pathogen is a common herpesvirus infection in immunocompromised children?

Answer 5

Cytomegalovirus (CMV)

It can be acquired through various means including intrapartum transmission.

Question 6

What is the typical histopathological finding in CMV-infected cells?

Answer 6

Basophilic nuclear inclusions surrounded by a clear halo

This gives an “owl eye” appearance.

Question 7

What is the preferred drug for the prevention and treatment of CMV disease?

Answer 7

Valganciclovir

It has improved oral bioavailability compared to ganciclovir.

Question 8

True or False: Respiratory Syncytial Virus (RSV) typically causes only upper respiratory tract infections.

Answer 8

False

RSV can progress to involve the lower respiratory tract.

Question 9

What is the treatment for moderate to severe hypoxemia due to Pneumocystis jirovecii pneumonia?

Answer 9

High-dose Trimethoprim-sulfamethoxazole (TMP-SMX) with adjuvant glucocorticoid therapy

TMP-SMX is the preferred agent for both prophylaxis and treatment.

Question 10

What are the common clinical features of Pneumocystis jirovecii pneumonia (PCP)?

Answer 10

Dyspnea, tachypnea, fever, cough

Clinical features are often nonspecific.

Question 11

What is the common diagnostic method for detecting adenovirus pneumonia?

Answer 11

Lung biopsy or brushings demonstrating typical adenoviral inclusions

Culture can also be used, but may be delayed due to empiric therapy.

Question 12

What is the histopathological feature of Aspergillus species in pneumonia?

Answer 12

Septate hyphae with regular 45-degree dichotomous branching

This is best seen with methenamine silver staining.

Question 13

What is the treatment of choice for invasive aspergillosis?

Answer 13

Voriconazole

Other options include itraconazole and amphotericin B.

Question 14

What are the primary causes of fungal sepsis and secondary pulmonary involvement in children?

Answer 14

Candida albicans, C. tropicalis

Neutropenic children colonized with C. tropicalis are at a higher risk for dissemination.

Question 15

What are the endemic soil fungi associated with pulmonary infections?

Answer 15

Histoplasma capsulatum, Blastomyces dermatitidis

Histoplasmosis is associated with bird or bat fecal material.

Question 16

What is the treatment for progressive disseminated histoplasmosis in immunocompromised patients?

Answer 16

Amphotericin B

Itraconazole can be used for patients without CNS involvement.

Question 17

What is the primary cause of pneumonia due to Toxoplasma gondii in immunocompromised patients?

Answer 17

CNS disseminated disease with secondary pulmonary involvement

It can present with shortness of breath and cough.

Question 18

What is a significant risk factor for bacterial infections in immunocompromised patients?

Answer 18

Neutropenia

Presence of indwelling venous catheters also increases risk.

Question 19

What can cause acute respiratory distress syndrome (ARDS) in liver transplant patients?

Answer 19

Cyclosporine early infusion

Most posttransplant medications do not cause direct lung toxicity.

Question 20

What is the recommended action if phrenic nerve function has not returned after a period of observation?

Answer 20

Plication

Plication is indicated if there is no improvement in 3 months or if there is clinical deterioration.

Question 21

What early complication can cyclosporine cause in liver transplant patients?

Answer 21

ARDS

Acute Respiratory Distress Syndrome (ARDS) has been reported with early infusion of cyclosporine.

Question 22

Which medications post-transplant have direct toxicity to the lung?

Answer 22

• Rapamycin
• Sirolimus
• Everolimus

Most post-transplant medications do not have direct lung toxicity except for these three.

Question 23

What causes Posttransplant Lymphoproliferative Disease (PTLD)?

Answer 23

Uncontrolled EBV-driven B cell proliferation

PTLD is due to immunosuppressive regimens causing T lymphocyte depletion.

Question 24

What is the median onset time for PTLD following solid-organ transplantation?

Answer 24

Within 24 months

Most cases of PTLD occur within the first two years post-transplant.

Question 25

What is the most common finding on chest X-ray (CXR) in PTLD?

Answer 25

Nodular abnormalities ## Footnote Nodular abnormalities are typically observed in PTLD cases.

Question 26

What is the initial therapy for PTLD?

Answer 26

* Reduction of immunosuppression * Antiviral agents * IV immunoglobulin * Rituximab ## Footnote Rituximab is an anti-B cell immunotherapy used in treatment.

Question 27

What are common sites for metastases in childhood tumors?

Answer 27

Lungs ## Footnote Common childhood tumors that metastasize to the lungs include Wilms tumor, sarcomas, and hepatoblastoma.

Question 28

What lung injuries can therapeutic doses of radiation cause?

Answer 28

* Acute radiation pneumonitis * Chronic radiation fibrosis ## Footnote These injuries are associated with higher thoracic radiation doses.

Question 29

What is the typical presentation time for radiation pneumonitis after treatment?

Answer 29

30–90 days ## Footnote Symptoms of radiation pneumonitis typically manifest within this timeframe.

Question 30

What is the treatment for radiation pneumonitis?

Answer 30

Systemic corticosteroids ## Footnote Corticosteroids are used to manage symptoms of radiation pneumonitis.

Question 31

What can cause pulmonary complications following Hematopoietic Stem Cell Transplantation (HSCT)?

Answer 31

Preexisting diseases treated with HSCT ## Footnote Some diseases may have significant pulmonary complications pre-transplant.

Question 32

What is the incidence rate of Peri-Engraftment Respiratory Distress Syndrome?

Answer 32

~5% ## Footnote This syndrome occurs within the first 14 days following HSCT.

Question 33

What are the two histopathological types of Idiopathic Pneumonia Syndrome (IPS)?

Answer 33

* Interstitial pneumonia * Diffuse alveolar damage ## Footnote These types characterize the lung injury seen in IPS.

Question 34

What is a characteristic finding in Bronchoalveolar Lavage (BAL) in cases of Diffuse Alveolar Hemorrhage post-HSCT?

Answer 34

Neutrophilia despite peripheral leucopenia ## Footnote This finding is indicative of the condition.

Question 35

What is a common late pulmonary complication following HSCT?

Answer 35

Obliterative Bronchiolitis (Bronchiolitis Obliterans Syndrome) ## Footnote This complication is associated with chronic lower airways obstruction.

Question 36

What clinical symptoms are associated with Bronchiolitis Obliterans Syndrome?

Answer 36

* Dyspnea * Wheezing * Nonproductive cough ## Footnote Fever is not a common symptom.

Question 37

What is the typical radiographic finding in patients with Bronchiolitis Obliterans Syndrome?

Answer 37

Usually normal chest radiograph ## Footnote However, hyperinflation and increased linear markings may be present.

Question 38

What is a common cause of Interstitial Lung Diseases in post-transplant patients?

Answer 38

Pre-HSCT exposure to cytotoxic drugs or irradiation ## Footnote These exposures often lead to progressive lung issues.

Question 39

What is Cryptogenic Organizing Pneumonia (COP) formerly known as?

Answer 39

Bronchiolitis obliterans with organizing pneumonia (BOOP) ## Footnote COP differs histologically and physiologically from bronchiolitis obliterans.

Question 40

What is the distinctive finding in Pulmonary Alveolar Proteinosis?

Answer 40

Lipoproteinaceous milky white fluid in the alveolar space ## Footnote This accumulation results in hypoxemia.

Question 41

What is the treatment for Pulmonary Alveolar Proteinosis?

Answer 41

Removal of excessive surfactant material ## Footnote This is achieved through sequential lavage.

Question 42

What are some specific agents that may cause pulmonary injury?

Answer 42

* Busulfan * Cyclophosphamide * Methotrexate * BCNU * Radiation ## Footnote These agents can lead to significant lung complications.

Question 43

What preventive strategies are recommended for immunocompromised pediatric patients?

Answer 43

* Good hand hygiene * Avoidance of exposure to sick contacts ## Footnote Contact precautions should be used as appropriate.

Question 44

What vaccinations are recommended prior to undergoing immunosuppression?

Answer 44

* Annual inactivated influenza vaccination * Pneumococcal vaccination at least 2 weeks prior to therapy ## Footnote Especially important for those at increased risk of pneumococcal infection.