Diversity and combinations of infectious agents in 38 adults with an infection-triggered reactive haemophagocytic syndrome: a multicenter study.

Reactive haemophagocytic syndrome (HS) is a rare condition that occurs in patients with infections, haematological malignancies or autoimmune diseases. Although various microorganisms are thought to trigger HS, most of the literature data on this topic have been gathered in single-centre case series. Here, we sought to characterize infectious triggers in a large, multicentre cohort of patients with HS. Patients were included in the present study if HS was solely due to one or more infections. Detailed microbiological data were recorded. Of the 162 patients with HS in the cohort, 40 (25%) had at least one infection and 38 of the latter (including 14 women, 36.8%) were included. The median age was 46 years. Seven patients were presumed to be immunocompetent (18.4%), whereas 19 patients (50%) were infected with human immunodeficiency virus and 12 patients (31.6%) were immunocompromised for other reasons. Twenty-seven patients (71.1%) had a single infection, whereas six (15.8%) and five (13.1%) patients had, respectively, two and three concomitant infections. We observed pyogenic bacterial infections (n = 7), tuberculosis (n = 10), non-tuberculous mycobacteriosis (n = 3), viral infections (n = 17: 11 cytomegalovirus, three Epstein-Barr virus, two human herpesvirus 8, one herpes simplex virus 2), parasitic infections (n = 8: four disseminated toxoplasmosis, one leishmaniasis, three malaria), fungal infections (n = 5: four pulmonary pneumocystosis and one candidaemia). Eighteen patients (47.4%) received corticosteroids and/or etoposide. Twelve patients died (31.6%). All multiple infections and all deaths occurred in immunocompromised patients. When compared with patients suffering from malignancy-associated HS, patients with infection-triggered HS were younger and more likely to be immunocompromised, and had a better outcome.

Vasculogenic mimicry of acute leukemic bone marrow stromal cells.

Angiogenesis is thought to be involved in the development of acute leukemia (AL). We investigated whether bone marrow stromal cells (BMSCs) derived from stem cells might be responsible for the increase in microvascular density (MVD), and compared 13 bone marrow samples from AL patients with 23 samples from patients in complete remission (controls). We demonstrated that AL-derived BMSC secreted more insulin growth factor-1 (IGF-1) and SDF-1alpha than controls. In addition, in contrast to normal adherent BMSCs, adherent BMSCs derived from CD133+/CD34+ stem cells from AL patients were able to form capillary-like structures ('vasculogenic mimicry') on Matrigel. The increase in vasculogenic mimicry occurred through PI3 kinase and rho GTPase pathway as inhibitors of these signaling pathways (wortmannin and GGTI-298, respectively) were able to reduce or prevent capillary tube formation. In normal BMSC, addition of exogenous IGF-1 generated capillary-like tubes through the same pathway as observed spontaneously in AL-derived BMSC. The involvement of IGF-1 in the mimicry process was confirmed by the addition of a neutralizing antibody against IGF-1R or a IGF-1R pathway inhibitor (picropodophyllin). In conclusion, AL-derived BMSC present functional abnormalities that may explain the increase in MVD in the bone marrow of AL patients.

Correlation between molecular and histopathological diagnoses of B cell lymphomas in bone marrow biopsy and aspirates.

AIMS: PCR has been shown previously to be the most sensitive technique to detect a clonal population in marrow aspirates (MAs), and the clinical standard for evaluation of bone marrow lymphoma involvement today is bone marrow trephine biopsy (BMTB). The goal of this study was to compare morphological evaluation of B cell neoplasm in BMTB (histology and immunohistochemistry) and PCR analysis in MA, with both specimens obtained at the same time, in patients with a known molecular marker of the disease. METHODS: This was a retrospective evaluation of 98 consecutive BMTB specimens from 60 patients with a known B-cell neoplasm and a previous PCR marker of the disease (BCL2 and/or IGH). RESULTS: Considering the IGH PCR cases alone, a B cell clone was detected in 85% and 39% of the morphology (M) positive and negative groups, respectively. Five M(+), IGH(-) cases were found, including two cases of follicular lymphoma (FL), one case of diffuse large B cell lymphoma, and two cases of mantle cell lymphoma. The FLs had about 20% and 50% of BMTB involvement each. All other cases had minimal lymphoma localisation. The two FLs were also BCL2-MBR(+). Use of BCL2-MBR detected all M(+) cases and 66% of M(-) cases whenever it was an initial marker of disease. CONCLUSIONS: IGH PCR alone is not good enough for BMTB assessment, especially in FL. On the other hand, the PCR study for BCL2 is more sensitive than morphology, without any false negative results in this series, suggesting that BCL2-MBR PCR on MA can be used as an alternative and more sensitive examination for disease evaluation, providing that there is careful analysis of data, adequate knowledge of PCR pitfalls and absence of other haematological disorders.

[Münchausen syndrome with forgery on biologic results. A case report]. / Pseudoleucémie par falsification d'examens biologiques: genèse d'un syndrome de Münchausen.

Münchausen syndrome is a disorder defined by the following: acute factitious symptoms leading to inappropriate investigation and therapy, a restless journey from hospital to hospital and autobiographical falsification. We report here a 20-year-old woman who presented at our hospital consultation of internal medicine with laboratory-test results suggesting the diagnosis of leukemia. A new complete blood cells count and a medullogram by sternal puncture did not show any abnormality. Comparative examination of laboratory-test sheets lead to the diagnosis of Münchausen syndrome as some results had been falsified. With unlimited access to information through internet and word or image processing softwares, laboratory results have become easy to falsify nowadays, particularly for patients with Münchausen syndrome, who may then be quite difficult to diagnose accurately in the context of medical consultation.