INFECTIONS IN HEMOPOEITIC STEM CELL TRANSPLANT RECIPIENTS

DR E.O SHOBOWALECLINICAL MICROBIOLOGIST

PATHCARE NIGERIA

OUTLINE

• Introduction • Infectious agents• Diagnosis• Prophylactic agents• PathCare’s role• Conclusion

INTRODUCTION

• The transplantation of haematopoietic stem cells from bone marrow results in a transient state of immunologic incompetence.

• Shortly after transplantation phagocytes, T and B cells are rapidly depleted and the host is extremely susceptible to various infections.

Infectious Agents

• Bacterial• Fungal• Parasitic• Viral

Infectious agentsSite of Infection < 28 days 1 to 4 months > 6 monthsDisseminated S aureus,

CONSNocardia, Candida, Aspergillus spp

H influenzae, S pneumoniae, N meningitides

Skin and Mucous Membranes

HSV HHV 6 VZV

Lungs Candida, Aspergillus spp, Klebsiella spp

CMV, Toxoplasma, P jiroveci

P jiroveci

GIT CMVKidney BK Virus,

AdenovirusBK Virus

Brain HHV 6 HHV 6, Toxoplasma

Toxoplasma, JC Virus

Bone Marrow HHV 6

Bacterial

• Usually seen in the first 28 days after HSCT.• Marked granulocytopenia is observed• Neutropenia usually lasts for 1 to 3 weeks.• However bacterial infections are more

common in the first 7 days• Organisms are usually from the Skin or

Intravenous catheters of recipients

Bacterial

• Staphylococcus aureus, Coagulase Negative Staphylococci are acquired from the skin and catheters.

• Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa are acquired from the bowel.

• Nocardia asteroides which is partially acid fast occurs after the first week of transplantation.

Bacterial

• Encapsulated bacteria such as Streptococcus pneumoniae cause infections in the late post transplantation period i.e. >6 months.

• Chemotherapy and the use of broad spectrum antimicrobial agents place recipients at risk of Clostridium difficile associated diarrhea.

Fungi

• Fungal infections tend to occur after the first week post transplantation.

• Seen after chemotherapy, steroid and broad spectrum antibiotic administration.

• Granulocytopenia predisposes towards Candida infections.

• The increased use of Fluconazole has also helped to select out Molds such as Aspergillus spp, Penicillium marfennei and Scedosporium spp

Fungi

• The following drugs predispose to fungal infections particularly Candida and Aspergillus spp infections in HSCT patients

Prednisolone

Cyclosporine

Tacrolimus

Mycophenolate

Rapamycin

Alemtuzumab

Fungi

• The above mentioned drugs may also cause reactivation of infections due to H

istoplasma capsulatum

Coccidioides imitis

Blastomyces dermatidis.

Fungi

• The prolonged use of intravenous lipid formulations for TPN may predispose to Malassaezia furfur infections

• HSCT patients are at increased risk of interstitial pneumonia due to Pneumocystis jiroveci.

Parasites

• Reactivation of Toxoplasmosis occurs in transplant recipients and may cause CNS lesions.

Viruses

•Occurs within 14 days post transplantation•Causes Mucositis, esophagitis and anogenital disease.HSV

•Reactivation of herpes zoster may occur in the first month especially with pre-transplant immunosuppression•Reactivation rates are more with allogeneic transplantationVZV•Seen 30 -90 days post transplantation with low granulocyte counts. Encountered in GVHD.•Causes interstitial pneumonia, colitis, BM suppression and graft failure.CMV

Viruses

•HHV 6 reactivates in 30% of children post HSCT•Reactivation is common in those receiving steroidsHHV6•Reactivation is secondary to marrow ablation•Lymphoproliferative disease occursEBV•Fatal pneumonias can occur•Hemorrhagic cystitis

Influenza, RSV, Adenoviruses

Clinical Syndromes

Hemorrhagic Cystitis •Elevated loads of BK Virus, Polyoma Virus, Adenovirus•Also HSV, CMV and HHV 6

Hepatitis •HBV, HCV, VZV, Adenovirus•Others include HSC and CMV

Pneumonia Syndromes •S pneumoniae, RSV, P jiroveci•H influenzae, Adenovirus

Clinical Syndromes

Diarrhea – 15% are due to infectious agents

Skin eruptions – due to VZV or fungi

Osteomyelitis – following marrow aspiration and usually due to S aureus

THE ROLE OF PATHCARE

• PathCare can reliably and accurately diagnose infectious syndromes pre and post transplantation.

• We have world class diagnostic equipments in all the 4 branches of Pathology – Microbiology, Clinical Chemistry, Hematology and Histopathology.

• PathCare has over 13 Pathologists on board who verify and help interpret laboratory reports

• Our pathologists are also available for consultation in the patient management

THE ROLE OF PATHCARE• We are located in the following areas• Lagos – Victoria Island, LUTH, FESTAC and Ikeja• Benin• Abuja• Portharcourt• Enugu• Warri• Kaduna• Gwagwalada• Ibadan• Illorin – opening in August

THE ROLE OF PATHCARE• PathCare was established in Nigeria in October 2004 due to demand

for accurate and reliable tests• It was started by consortium of health care practitioners including

pathologists, haematologists, gynaecologists amongst others who required precision and a wider range of testing to ensure more favourable outcomes for their patients

• Sought reputable Partners: PathCare South Africa (foremost pathology service in South Africa). **First to achieve ISO Accreditation in South Africa with an unparalleled reputation for quality and service.

• PathCare has since enjoyed a meteoric rise (3 Laboratories and 9 Depots and still growing) in demand for its tests because of the trust clinicians have in the brand

THE ROLE OF PATHCARE• Our Consultant Pathologists• Prof. Ibironke Akinsete Consultant Haematologist and Chairman Board of

Directors• Dr. Tunji Soriyan Consultant Chemical Pathologist• Dr. Abiola Ogbenna Consultant Haematologist• Prof. Folasade Ogunsola Consultant Microbiologist• Dr. Jaf Momoh Consultant Chemical Pathologist• Dr. Adediran Consultant Haematologist• Dr. Tamuno Wakama Consultant Haematologist • Dr Olushola Shobowale Consultant Microbiologist• Dr Tolulope Adewole Consultant Chemical Pathologist• Over 70 Specialist Pathologists available in SA for referrals and second

opinions

THE ROLE OF PATHCARE

• We are currently the first and only ISO 15189 accredited laboratory in West Africa.

• This means that our test methodologies and results meet international standards and are acceptable outside Nigeria.

THE ROLE OF PATHCARE

• Accurate and reliable results

• Highly specialised testing

• Timely results (Fast Turn around time)

• Excellent service

• Nationwide Access

THE ROLE OF PATHCARE

• TECHNOLOGY– New Methodology – New Processes …– Wider range of tests

• TRAINING New Skills, Attitudes & Techniques

• COMPUTERIZATION– Improved efficiency & accuracy– Reduction of Errors due to human intervention

• TOTAL QUALITY MANAGEMENT

THE END

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