Disseminated Microsporidiosis in an Immunosuppressed Patient

We report a case of disseminated microsporidiosis in a patient with multiple myeloma who had received an allogeneic stem cell transplant requiring substantial immunosuppression. The causative organism was identified as Tubulinosema acridophagus, confirming this genus of microsporidia as a novel human pathogen

National Institutes of Health Hematopoietic Cell Transplantation Late Effects Initiative: The Immune Dysregulation and Pathobiology Working Group Report

Immune reconstitution after hematopoietic stem cell transplantation (HCT) beyond 1 year is not completely understood. Many transplant recipients who are free of graft-versus-host disease (GVHD) and not receiving any immunosuppression more than 1 year after transplantation seem to be able to mount appropriate immune responses to common pathogens and respond adequately to immunizations. However, 2 large registry studies over the last 2 decades seem to indicate that infection is a significant cause of late mortality in some patients, even in the absence of concomitant GVHD. Research on this topic is particularly challenging for several reasons. First, there are not enough long-term follow-up clinics able to measure even basic immune parameters late after HCT. Second, the correlation between laboratory measurements of immune function and infections is not well known. Third, accurate documentation of infectious episodes is notoriously difficult. Finally, it is unclear what measures can be implemented to improve the immune response in a clinically relevant way. A combination of long-term multicenter prospective studies that collect detailed infectious data and store samples as well as a national or multinational registry of clinically significant infections (eg, vaccine-preventable severe infections, opportunistic infections) could begin to address our knowledge gaps. Obtaining samples for laboratory evaluation of the immune system should be both calendar and eventdriven. Attention to detail and standardization of practices regarding prophylaxis, diagnosis, and definitions of infections would be of paramount importance to obtain clean reliable data. Laboratory studies should specifically address the neogenesis, maturation, and exhaustion of the adaptive immune system and, in particular, how these are influenced by persistent alloreactivity, inflammation, and viral infection. Ideally, some of these long-term prospective studies would collect information on long-term changes in the gut microbiome and their influence on immunity. Regarding enhancement of immune function, prospective measurement of the response to vaccines late after HCT in a variety of clinical settings should be undertaken to better understand the benefits as well as the limitations of immunizations. The role of intravenous immunoglobulin is still not well defined, and studies to address it should be encouraged

Establishment of early donor engraftment after reduced-intensity allogeneic hematopoietic stem cell transplantation to potentiate the graft-versus-lymphoma effect against refractory lymphomas

AbstractReduced-intensity allogeneic hematopoietic stem cell transplantation (alloHSCT), which typically results in mixed chimerism initially after transplantation, has had limited efficacy in chemotherapy-refractory lymphomas. We hypothesized that the rapid establishment of complete donor chimerism would potentiate a graft-versus-lymphoma effect. Fifteen patients with chemotherapy-refractory lymphoma initially received induction with a conventional chemotherapy regimen (etoposide, prednisone, vincristine, cyclophosphamide, adriamycin, fludarabine [EPOCH-F]) to deplete host T cells and provide disease control prior to alloHSCT. Patients then received conditioning with fludarabine and cyclophosphamide followed by alloHSCT from HLA-matched siblings. Graft-versus-host disease prophylaxis consisted of cyclosporine alone. EPOCH-F resulted in 73% of patients having partial responses or stable disease. EPOCH-F depleted host CD4+ T cells from a median of 235 cells/μL to 56 cells/μL. Fourteen patients underwent alloHSCT, and all had >95% donor engraftment by day 14 after transplantation. The incidence of Grade II to III acute graft-versus-host disease was 71%. There were two therapy-related deaths. There were 8 partial responses and 3 complete responses (CRs) at day 28. Five additional CRs were observed at day 100 without withdrawal of cyclosporine or donor lymphocyte infusion. The rate of CRs for all 15 patients was 60%. The 1-year progression-free survival rate from time of study entry is 67% with only 1 relapse among 9 CRs. At a median potential follow-up of 28 months, the overall survival rate is 53%. These data demonstrate that a potent and durable graft-versus-lymphoma effect can occur against chemotherapy-refractory lymphomas and suggest that this effect may be associated with rapid, complete donor chimerism after reduced-intensity alloHSCT. © 2003 American Society for Blood and Marrow TransplantationBiology of Blood and Marrow Transplantation 9:162-169 (2003

Ancillary Therapy and Supportive Care of Chronic Graft-versus-Host Disease: National Institutes of Health Consensus Development Project on Criteria for Clinical Trials in Chronic Graft-versus-Host Disease: V. Ancillary Therapy and Supportive Care Working Group Report

AbstractThe Ancillary Therapy and Supportive Care Working Group had 3 goals: (1) to establish guidelines for ancillary therapy and supportive care in chronic graft-versus-host disease (GVHD), including treatment for symptoms and recommendations for patient education, preventive measures, and appropriate follow-up; (2) to provide guidelines for the prevention and management of infections and other common complications of treatment for chronic GVHD; and (3) to highlight the areas with the greatest need for clinical research. The definition of “ancillary therapy and supportive care” embraces the most frequent immunosuppressive or anti-inflammatory interventions used with topical intent and any other interventions directed at organ-specific control of symptoms or complications resulting from GVHD and its therapy. Also included in the definition are educational, preventive, and psychosocial interventions with this same objective. Recommendations are organized according to the strength and quality of evidence supporting them and cover the most commonly involved organs, including the skin, mouth, female genital tract, eyes, gastrointestinal tract, and lungs. Recommendations are provided for prevention of infections, osteoporosis, and steroid myopathy and management of neurocognitive and psychosocial adverse effects related to chronic GVHD. Optimal care of patients with chronic GVHD often requires a multidisciplinary approach

Human Dectin-1 Deficiency Impairs Macrophage-Mediated Defense Against Phaeohyphomycosis

Subcutaneous phaeohyphomycosis typically affects immunocompetent individuals following traumatic inoculation. Severe or disseminated infection can occur in CARD9 deficiency or after transplantation, but the mechanisms protecting against phaeohyphomycosis remain unclear. We evaluated a patient with progressive, refractory Corynespora cassiicola phaeohyphomycosis and found that he carried biallelic deleterious mutations in CLEC7A encoding the CARD9-coupled, β-glucan-binding receptor, Dectin-1. The patient\u27s PBMCs failed to produce TNF-α and IL-1β in response to β-glucan and/or C. cassiicola. To confirm the cellular and molecular requirements for immunity against C. cassiicola, we developed a mouse model of this infection. Mouse macrophages required Dectin-1 and CARD9 for IL-1β and TNF-α production, which enhanced fungal killing in an interdependent manner. Deficiency of either Dectin-1 or CARD9 was associated with more severe fungal disease, recapitulating the human observation. Because these data implicated impaired Dectin-1 responses in susceptibility to phaeohyphomycosis, we evaluated 17 additional unrelated patients with severe forms of the infection. We found that 12 out of 17 carried deleterious CLEC7A mutations associated with an altered Dectin-1 extracellular C-terminal domain and impaired Dectin-1-dependent cytokine production. Thus, we show that Dectin-1 and CARD9 promote protective TNF-α- and IL-1β-mediated macrophage defense against C. cassiicola. More broadly, we demonstrate that human Dectin-1 deficiency may contribute to susceptibility to severe phaeohyphomycosis by certain dematiaceous fungi

Hemophagocytic Lymphohistiocytosis Secondary to Disseminated Histoplasmosis in Rheumatologic Disease

Background. Hemophagocytic lymphohistiocytosis (HLH) was originally described in pediatric patients presenting with fever, hepatosplenomegaly, and blood cell abnormalities. Later, HLH was recognized to occur in adults, often associated with hematologic malignancies or serious infections. Conclusion. Patients presenting with HLH are critically ill, and rapid diagnosis is key. In adults, the search for the trigger must begin promptly as time to diagnosis effects survival. The underlying trigger in our patients was Histoplasma capsulatum infection, which is rare in the southwestern United States. Prompt diagnosis led to recovery in one patient, while the other did not survive

Coccidioidomycosis in Allogeneic Stem Cell Transplant Recipients: Case Series and Review of the Literature

Coccidioides is an endemic fungus of the Southwest United States that causes the disease coccidioidomycosis. Immunocompromised persons are at increased risk for severe infection and dissemination. One such population is allogeneic bone marrow transplant (allo-HCT) recipients, but accounts of coccidioidal infection in these patients have rarely been documented. We present two cases of Coccidioides in allo-HCT recipients with good outcomes: one patient who developed pulmonary coccidioidomycosis in the late post-engraftment phase and another with known controlled disseminated infection at the time of transplant. A review of the literature identified 19 allo-HCT recipients with coccidioidomycosis. Due to the limited published literature, no guidelines have yet been established regarding optimal prophylaxis and treatment of Coccidioides infection in allo-HCT recipients. Candidates for transplantation should undergo a rigorous pre-transplant assessment to identify evidence of prior or active coccidioidomycosis. In our experience, patients who visit or live in Coccidioides-endemic areas should receive primary prophylaxis for at least the first 100 days post-transplant, and duration should be extended as long as the patient remains on immunosuppression. Those with prior infection should receive secondary prophylaxis while immunosuppressed. Patients with active infection should have treatment and stabilization of infection and continue anti-fungal treatment through immunosuppression