Lung diseases after bone marrow transplantation. Results of a clinical, radiological, histological, immunological and lung function study

Bacterial Pathogens Causing Pneumonia Post Hematopoietic Stem Cell Transplant: The Chronic GVHD Population

Allogeneic stem cell transplantation is a lifesaving treatment for many malignancies. Post-transplant patients may suffer from graft versus host disease in the acute and/or the chronic form(s). Post-transplantation immune deficiency due to a variety of factors is a major cause of morbidity and mortality. Furthermore, immunosuppression can lead to alterations in host factors that predisposes these patients to infections. Although patients who receive stem cell transplant are at an increased risk of opportunistic pathogens, which include fungi and viruses, bacterial infections remain the most common cause of morbidity. Here, we review bacterial pathogens that lead to pneumonias specifically in the chronic GVHD population.

Pulmonary infections after bone marrow transplantation: clinical and radiographic findings

PURPOSE

To assess the clinical and radiographic findings of pulmonary infections diagnosed by using invasive means.

MATERIALS AND METHODS

Fifty-nine episodes of pulmonary infection were diagnosed in 52 (7.2%) of a consecutive series of 725 adult bone marrow transplant recipients. Causative organisms, time of diagnoses, radiographic patterns, and mortality rates were reviewed.

RESULTS

Cytomegalovirus and Aspergillus species were the two most common pathogens, accounting for 22 and 17 episodes, respectively. During the first 30 days after bone marrow transplantation, fungi caused the majority (nine [82%] of 11 episodes) of pulmonary infections; from days 31 to 100, viruses predominated (21 [62%] of 34 episodes). Recipients of allogeneic transplants had a higher probability of developing Cytomegalovirus pneumonitis than did the recipients of autologous and syngeneic transplants (P < .001). Radiographic findings of Cytomegalovirus pneumonia consisted of parenchymal opacification (90%) and innumerable nodules smaller than 5 mm (29%); in two patients, radiographs were normal. Nodules, masses, or nodules and masses, present in nine (69%) of the 13 patients with Aspergillus infection, were the most common radiographic findings in invasive aspergillosis. Bone marrow transplant recipients with a documented pulmonary infection were found to have a lower event-free survival than recipients without infection (P < .001).

CONCLUSION

Opportunistic pathogens account for the majority of pulmonary infections requiring invasive diagnosis and tend to manifest at predictable times in the course of events following recovery from bone marrow transplantation. Cytomegalovirus, the most common pathogen, causes a spectrum of radiographic findings that includes normal findings. Occurrence of a pulmonary infection is associated with an increased mortality rate.

[Transplantation of hematopoietic stem cells. I: Definitions, principle indications, complications]

The transplantation of hematopoietic and lymphopoetic stem and progenitor cells has become a standard procedure for the treatment of many malignant diseases. Autologous stem cells are derived from the patient himself, allogeneic cells from an HLA-identical or HLA-compatible family or unrelated donor. Hematopoietic stem cells can be obtained from bone marrow, blood and fetal cord blood. After 3 to 5 days treatment, the granulocyte-colony stimulating factor (G-CSF) mobilizes stem- and progenitor cells from the marrow into the blood. This method is now standard in autologous transplantation and is increasingly preferred in allogeneic transplantation. The time to hematopoietic recovery is shorter with blood stem cells than with bone marrow cells. With myeloablative high dose therapy followed by stem cell transplantation, long term disease free survival is possible in many cases and great proportions of patients can be cured (see part II). Improvements of supportive care have reduced toxicity of treatment substantially, however severe complications still occur at oropharynx, gastrointestinal tract, liver, lung, skin, kidney, urinary tract and nervous system. After allogeneic transplantation immunocompetent donor cells can react with the recipients tissue. In HLA-identical donor and recipients differences in the minor histocompatibility antigens account for this graft-versus-host-reaction (GvH), which is mainly mediated by transplanted T-cells. The GvH-reaction can affect skin, liver, gut and other organs and cause clinically relevant GvH-disease (GvHD). The GvHD is more severe in HLA-mismatched or unrelated transplantations. Immunodeficiency and organ dysfunction due to GvHD may predispose infections and impair the outcome of transplantation. Unrelated cord blood stem cells may have a minor risk of inducing acute GvHD, as stem and T-cells are immature. After allogeneic stem cell transplantation, the relapse rate of leukemia or lymphoma is significantly reduced by immunoreactive cells:graft-versus-tumor (GvT) or graft-versus-leukemia effect (GvL).

The chest radiograph appearances seen following high dose chemotherapy and autologous bone marrow transplantation for resistant malignant lymphoma

The objective of this study was to review and analyse the chest radiograph (CXR) appearances seen following high dose chemotherapy and autologous bone marrow transplantation (ABMT), and to identify any characteristic patterns. Thirty-one patients underwent ABMT between 1984 and 1989 for high grade lymphoma resistant to conventional chemotherapy. Their case notes and CXRs were reviewed in conjunction with the clinicians. In this small sample of patients, an acute interstitial pattern was seen with pulmonary oedema following bone marrow reinfusion in two cases of the 13 patients showing CXR changes (15%). Otherwise, the CXR changes following ABMT were not specific, although they did alert the clinician to the possibilities of recurrent lymphoma or opportunistic infection, enabling appropriate investigations and treatment to be instituted at an early stage. The complications and CXR changes did not differ greatly from those seen following allogeneic bone marrow transplantation.

Allogeneic bone marrow transplantation for Langerhans' cell histiocytosis

A group of proliferative diseases of the epidermal Langerhans' cells are commonly referred to as Langerhans' cell histiocytosis (LCH). A small number of the patients with this disease face an unfavorable disease course despite chemotherapy and radiation therapy. In LCH patients with a poor prognosis, allogeneic bone marrow transplantation (BMT) could be the appropriate treatment with proven antiproliferative effects and may be able to repopulate the recipient with stem cell-derived Langerhans' cells from the donor or correct the presumed underlying immunodeficiency. An LCH was diagnosed in a 15-year-old boy with multiple osteolytic lesions, anemia, and diabetes insipidus centralis. Repeated flare-ups of the disease had necessitated several courses of conventional chemotherapy including cyclophosphamide (CY), prednisolone (P), 6-mercaptopurine (6-MP), vincristine (VCR), and additional local irradiation without stable remission. Three years after first being diagnosed with LCH the patient underwent high-dose chemotherapy-radiation therapy followed by allogeneic BMT from his human lymphocyte antigen (HLA)-identical brother. Currently, he is alive and well and has been disease-free for more than 41 months after BMT.