First case report of bloodstream infection by Rhizomucor pusillus in a child with hemophagocytic lymphohistiocytosis.
ABSTRACT: We describe an unusual presentation of fatal infection due to Rhizomucor pusillus bloodstream infection in a 12-year old pediatric patient recently diagnosed with hemophagocytic lymphohistiocytosis. R. pusillus was isolated from one blood culture drawn on Day 11 of hospitalization.
Project description:Mycobacterium iranicum has recently been recognised as an opportunistic human pathogen. Although infectious conditions represent frequent triggers for hemophagocytic lymphohistiocytosis, non-tuberculous mycobacterial infections are rarely associated with this entity. To this date, M. iranicum infection has never been reported in France, has never been associated with hemophagocytic lymphohistiocytosis and has never been found to be multi-resistant on standardized antimicrobial susceptibility testing.We report a case of a French Caucasian man with secondary hemophagocytic lymphohistiocytosis in the context of M. iranicum bacteraemia and Hodgkin's disease. We review available data concerning M. iranicum antimycobacterial susceptibility testing and treatment outcomes. We also review the association between hemophagocytic lymphohistiocytosis and non-tuberculous mycobacterial infections.Interpretation of M. iranicum positive cultures remains a clinical challenge and non-tuberculous mycobacterial infections need to be considered in secondary hemophagocytic lymphohistiocytosis differential diagnosis.
Project description:Sinus-orbital zygomycosis caused by Rhizomucor pusillus in a patient with acute myelogenous leukemia is described. Identification was achieved by sequencing of the internal transcribed spacer (ITS) regions of the rRNA gene and by expression of zygospores in mating. This report highlights the value of ITS sequencing as a diagnostic tool for the identification of R. pusillus and expands the understanding of infection types caused by this zygomycete.
Project description:Adult hemophagocytic lymphohistiocytosis is a secondary immunopathologic phenomenon, mainly secondary to malignancy, infection, or autoimmune disorders. The performance of diagnostic criteria, studied in the pediatric population, is yet to be validated in the adult population. Some of the criteria include cytopenias and organomegaly that are inherent features to malignant processes, thus making the diagnosis of hemophagocytic lymphohistiocytosis a challenge in patients with cancer.We describe the case of a 54-year-old white man with history of metastatic maxillary sinus adenoid cystic carcinoma who had severe liver injury and cytopenias with progressive clinical deterioration. We performed an evaluation, by flow cytometry, of the expression of surface markers in his natural killer cells that revealed remarkable abnormalities. His syndrome eventually fulfilled criteria for hemophagocytic lymphohistiocytosis and he received therapy with steroids with interval clinical improvement. Unfortunately, he refused further cytotoxic treatment and died 2 weeks later.The conventional criteria for the diagnosis of hemophagocytic lymphohistiocytosis are suboptimal for adult patients with cancer resulting in delays in diagnosis and timely initiation of treatment. The diagnostic criteria have to be re-evaluated in patients with cancer; novel, easily available, and accurate diagnostic methods are needed.
Project description:Epstein-Barr virus (EBV) is a ubiquitous virus that infects nearly all people worldwide without serious sequela. However, for patients who have genetic diseases which predispose them to the development of hemophagocytic lymphohistiocytosis (HLH), EBV infection is a life-threatening problem. As a part of a themed collection of articles on EBV infection and human primary immune deficiencies, we will review key concepts related to the understanding and treatment of HLH.
Project description:Hemophagocytic lymphohistiocytosis, also known as a hemophagocytic syndrome, is a life-threatening condition that can develop in critically ill patients with malignancies, severe infections, during chemotherapy, and may be associated with currently known or unknown genetic abnormalities; however, this list of potential causes can be extensive. The purpose of this study is to draw attention to the accuracy of its diagnostic criteria, association with a variety of clinical conditions, pathophysiological mechanisms, and outcomes of the diseases. From the medical records in our hospital, we retrospectively extracted 13 cases with hemophagocytosis over a 10-year period. Subsequently, we thoroughly analyzed medical records for the criteria used, the time required for making a diagnosis, adequacy of the criteria, management, and outcomes. We found that not all criteria were used for diagnosis, and the most sensitive and specific tests (genetic study, ferritin, and soluble IL-2r levels) were sometimes bypassed. Late diagnosis delayed management of some patients. Only a few treatment options were used for patient care. The hemophagocytic syndrome is a very rare and fatal entity requiring highly sensitive and specific diagnostic criteria for prompt diagnosis, targeted management, and thorough follow-up. Every patient admitted to the hospital with life-threatening conditions should be suspected and tested for the hemophagocytic syndrome as early as possible. The criteria for hemophagocytic lymphohistiocytosis should be revised, with the most sensitive and specific ones being done in all cases. Subsequently, each patient should be tested for the presence of genetic abnormalities that correlate with the syndrome.
Project description:Autoimmune lymphoproliferative syndrome (ALPS) is a rare inherited disorder of apoptosis, most commonly due to mutations in the FAS (TNFRSF6) gene. It presents with chronic lymphadenopathy, splenomegaly, and symptomatic multilineage cytopenias in an otherwise healthy child. Unfortunately, these clinical findings are also noted in other childhood lymphoproliferative conditions, such as leukemia, lymphoma, and hemophagocytic lymphohistiocytosis, which can confound the diagnosis. This report describes a 6-year-old girl with symptoms misdiagnosed as hemophagocytic lymphohistiocytosis and treated with chemotherapy before the recognition that her symptoms and laboratory values were consistent with a somatic FAS mutation leading to ALPS. This case should alert pediatricians to include ALPS in the differential diagnosis of a child with lymphadenopathy, splenomegaly, and cytopenias; obtain discriminating screening laboratory biomarkers, such as serum vitamin B-12 and ferritin levels; and, in the setting of a highly suspicious clinical scenario for ALPS, pursue testing for somatic FAS mutations when germ-line mutation testing is negative.
Project description:Hemophagocytic lymphohistiocytosis is a disease process characterized by unregulated hyperactivation of the immune system associated with multiorgan involvement and high mortality rates. Early recognition is crucial and a recently validated diagnostic schema, the H-Score, may facilitate diagnosis particularly in secondary hemophagocytic lymphohistiocytosis cases. We present a patient with secondary hemophagocytic lymphohistiocytosis in association with metastatic renal cell carcinoma in whom high-dose steroid therapy induced a remarkable response.A 35-year-old Vietnamese man with quiescent systemic lupus erythematosus was diagnosed 5 months prior to admission with left-sided renal cell carcinoma metastatic to the pancreas and spine. Ten days prior to admission, a febrile illness (temperatures to 39 °C) associated with flu-like symptoms unresponsive to levofloxacin developed. He took only two doses of pazopanib prior to admission. High fevers unresponsive to antimicrobial therapy, cytopenias, disseminated intravascular coagulation, and progressive multiorgan failure led to intubation and intensive care unit stay. Extensive infectious disease workup showed only negative results, but elevation of interleukin-2 receptor, exceedingly high ferritin levels and other features earned an H-Score of 302, consistent with >99% diagnostic probability for secondary hemophagocytic lymphohistiocytosis. High-dose steroid therapy produced a rapid clinical and biochemical response.Hemophagocytic lymphohistiocytosis is a life-threatening disorder which is likely to be under-recognized. Increased awareness of this disease entity and its diagnosis is crucial toward early recognition and treatment. To our knowledge, our patient is only the second reported with secondary hemophagocytic lymphohistiocytosis occurring in the setting of renal cell carcinoma.
Project description:<h4>Background</h4>In adult patients with secondary hemophagocytic lymphohistiocytosis (sHLH), no valid immune biomarker has been available for predicting the prognosis of untreated sHLH patients.<h4>Methods</h4>Circulating plasma levels of fibrinogen (FIB) were measured at diagnosis in 293 cases of adult sHLH. We categorized FIB levels into tertiles. Multivariable Cox proportional hazards models were used to evaluate the relationship between FIB and survival. Restricted cubic spline models and two-piecewise Cox proportional hazards models were used to address the nonlinear association between FIB and mortality.<h4>Results</h4>During a median follow-up of 52 (interquartile ranges, 18-221) days, 208 deaths occurred, with 137 deaths in malignancy-associated hemophagocytic lymphohistiocytosis (MHLH) and 71 deaths in non-malignancy-associated hemophagocytic lymphohistiocytosis (non-MHLH). After multivariable adjustment, compared with the highest tertile of FIB, the hazard ratios (HRs) with 95% confidence intervals (CIs) of survival for tertile 2 and tertile 1 were 1.06 (0.90-1.24) and 0.84 (0.71-0.98), respectively. The restricted cubic spline curve displayed a nonlinear and inverse relationship between FIB and mortality. Furthermore, the threshold effect analysis demonstrated that the inflection point for the curve was at an FIB level of 1.76 g/L. The HRs (95% CIs) for survival were 0.68 (0.55-0.83) and 1.08 (0.96-1.21) on the left and right side of the inflection point, respectively.<h4>Conclusions</h4>These results suggest that plasma fibrinogen is nonlinearly and inversely associated with the risk of mortality in adult secondary hemophagocytic lymphohistiocytosis.
Project description:In this report, we evaluate the hypothesis that hemophagocytic lymphohistiocytosis in patients with defects of lymphocyte cytotoxicity is usually triggered by infections. We show that in the majority of patients, extensive virus PCR panels performed in addition to routine microbiological investigations remain negative and summarize 25 patients with onset of hemophagocytic lymphohistiocytosis in utero or within the first 10 days of life, in none of which an associated bacterial or viral infection was reported. These observations, even though preliminary, invite to consider a key role of lymphocyte cytotoxicity in controlling T-cell homeostasis also in the absence of apparent infectious stimuli.