Accuracy of the Criteria for Hemophagocytic Lymphohistiocytosis

Introduction/Objective Regular assessment and analysis of diagnostic criteria for any type of human pathology is a prerequisite for ensuring the highest level of patient care. Hemophagocytic lymphohistiocytosis, also known as hemophagocytic syndrome, is a life-threatening condition. The syndrome can develop in critically ill patients with malignancies, severe infections, during chemotherapy, and may be associated with currently known genetic abnormalities, but this list is incomplete. We draw attention to the accuracy of diagnostic criteria, association with a variety of clinical conditions, pathophysiological mechanisms, and outcomes of the disease. Methods From the medical records in our hospital, we were able to extract several cases over a 10-year period. Based on hemophagocytosis features, our list included 13 patients representing 11 bone marrow aspirates, 4 lymph node biopsies, 1 liver biopsy, and 1 spleen sample; repeated examination of the slides confirmed the accuracy. Analyzing medical documentation, we evaluated the sequence and competence of the criteria used, the time required for diagnosis, management, and outcomes. Results We found that not all criteria were used for diagnosis, and the most sensitive and specific tests were bypassed. The preliminary diagnosis was made by a consultant (a rheumatologist or an oncologist-hematologist) on the 5th day of the hospital stay that delayed treatment. Of all the available treatment options, only a few were used. Conclusion The hemophagocytic syndrome is a very rare and fatal entity, it requires highly sensitive and specific diagnostic criteria for prompt diagnosis, targeted management, and thorough follow up. Every patient admitted to the hospital with a life-threatening condition should be suspected and tested for hemophagocytic syndrome on the first day. The criteria for hemophagocytic lymphohistiocytosis should be revised, with the most sensitive and specific ones are done in 100% of cases. Subsequently, each patient should be tested for the presence of genetic abnormalities that correlate with the syndrome.

Detection of a novel haemoplasma species in fattening pigs with skin alterations, fever and anaemia

BackgroundIn a fattening farm in Southern Germany, skin alterations (urticaria, haemorrhagic diathesis) and high fever were observed in 30% of the pigs 2 weeks after arrival. Feed intake was severely compromised in affected pigs.MethodsAfter detailed clinical observation, blood samples from affected pigs were collected for haematological, PCR and serological investigations. In addition, pathological investigations were performed on one pig.Results and conclusionAnalysis of blood parameters revealed a normocytic, normochromic anaemia. A novel porcine haemoplasma species was detected in blood samples of affected pigs and spleen sample of the necropsied pig by PCR. Phylogenetic analyses based on the 16S rDNA showed 99% identity to a novel porcine haemoplasma (‘Candidatus (Ca.) M. haemosuis’) species which has recently been described in China. Interestingly, this is the first report of ‘Ca. M. haemosuis’ in pigs with clinical signs resembling those of Mycoplasma (M) suis and the first description of this novel haemoplasma species outside Asia. On-farm affected pigs were treated with oxytetracycline and non-steroidal anti-inflammatory drugs. Clinical signs improved after implementation of treatment and optimisation of management procedures. This case might indicate that other porcine haemoplasma species than M suis can induce fever and skin alterations and may have an economic impact on affected farms.

A Promoting Effect Of Spleen On Disseminated Leukemia Cells

Abnormal environment not only takes part in the malignant transformation of hematopoietic cells but also has great impact on the development of hematopoietic malignancies. Leukemia cells arise from a specific environment and compete with normal cells from the beginning of leukemogenesis. Then they induce leukemic environment favorable for the outgrowth of themselves. Both bone marrow (BM) and spleen are involved and other organs are also infiltrated by leukemia cells at late stage. Splenomegaly is more frequently observed in T cell acute lymphoblastic leukemia (T-ALL), and is related to the poor prognosis of patients. However, the mechanism is not clear. In this study, we used the non-radiated Notch1-induced mouse T-ALL model to study the effects of spleen and BM environment on the early residing, malignant phenotype and dissemination of leukemia cells. The gross change of organs during the development of leukemia was analyzed and the earliest, sustained and a final 12.25±0.6802-time increase in weight could be observed in spleen. Though leukemia cells could be detected in all organs analyzed at late stage, the earliest and sustained increase was detected in spleen but not in BM. Furthermore, two-photon fluorescence microscopy analysis showed that more leukemia cells were found in spleens but not in BM within 3 days post-transplantation. These results suggested that spleen may be more important for the initiation and early development of Notch1 induced T-ALL than any other organs. In vitro transwell experiment showed that more leukemia cells migrated to lower chambers with normal spleen cells than with normal BM cells. The concentration of a panel of cytokines/chemokines in BM, spleen and peripheral blood was screened pre-transplantation or within 3 days post-transplantation. Notably, the concentration of MIP-3β was higher in spleen sample at day 0, and it increased rapidly and kept at high levels within 3 days. Further evidence showed that leukemia cells expressed basal level of CCR7 and MIP-3β, and higher level of them could be observed when leukemia cells were co-cultured with spleen cells but not BM cells. Moreover, transwell experiment confirmed that MIP-3β promoted the migration of leukemia cells. Then we study the effects of spleen environment on leukemia cells. Spleen cells were more potent to stimulate the proliferation of leukemia cells than BM cells. Leukemia cells co-cultured with spleen cells were more potent to migrate in the in vitro migration assay than those co-cultured with BM cells. Leukemia cells freshly isolated from spleen expressed higher level of both MIP-3β and CCR7. When same amount of leukemia cells were injected to mice, spleen-origin leukemia cells caused shorter life span than BM-origin leukemia cells. Therefore, spleen environment promotes the malignant phenotype of leukemia cells. In vivo experiments were then carried out to see whether splenectomy had effect on the survival of leukemia mice. The survival time of mice in either group (splenectomy pre- or post-injection of leukemia cells) was significantly longer than that in the sham group. Furthermore, distinct effects could be observed in mice groups underwent splenectomy at both early stage and late stage post-injection of leukemia cells. Moreover, less severe invasion and destruction of organ structures in thymus, lymph nodes and BM could be observed in two splenectomy groups. In summary, our work demonstrates that spleen has a promoting effect on disseminated leukemia cells. The highly expressed MIP-3β in the spleen environment recruits leukemia cells. Subsequently, spleen environment promotes the proliferation of leukemia cells, stimulates the expression of CCR7, and enhances the migration ability of leukemia cells. The removal of spleen could prolong the survival of leukemia mice. Therefore, this study provides evidence for an organ specific effect on emerging leukemia cells in vivo and has implications for developing new treatments for leukemia patients. Disclosures: No relevant conflicts of interest to declare.

Transmission Dynamics of Bartonella sp. Strain OE 1-1 in Sundevall's Jirds (Meriones crassus)

ABSTRACTA high prevalence ofBartonellainfection is found in many natural systems; however, the transmission dynamics leading to observations of these infections is not fully understood. The capability ofXenopsylla ramesisfleas to serve as competent vectors ofBartonellasp. OE 1-1 (a strain closely related to the zoonoticBartonella elizabethae) toMeriones crassusjirds was investigated. NaïveX. ramesisfleas were placed for 72 h on naïve jirds or jirds that were either experimentally or naturally infected withBartonellasp. strain OE 1-1, after which they were placed on naïve jirds. Postfeeding, 69 to 100% of the fleas collected from eachBartonella-positive jird containedBartonellaDNA, and all naïve jirds became positive forBartonellasp. OE 1-1 after infestation with the infected fleas. In addition, maternal transmission ofBartonellasp. OE 1-1 in jirds was tested by mating 5Bartonella-positive and 5 naïve female jirds with 10 naïve male jirds in the absence of fleas. Fifteen offspring were delivered by each group. Cultures of blood drawn from all offspring on days 35 and 47 postdelivery were found to be negative forBartonella. A single spleen sample from the offspring of aBartonella-positive mother was found molecularly positive forBartonellasp. OE 1-1. This study demonstrates thatX. ramesisfleas are competent vectors ofBartonellasp. OE 1-1 toM. crassusjirds and indicates that maternal transmission is probably not the major transmission route from female jirds to their offspring. We suggest that the dynamics ofBartonellasp. OE 1-1 in theM. crassusjird population in nature is mostly dependent on its vectors.

Comparison of Polymerase Chain Reaction and Virus Isolation for Detection of Epizootic Hemorrhagic Disease Virus in Clinical Samples from Naturally Infected Deer

We compared our recently reported reverse transcriptase polymerase chain reaction (PCR)-based assay for detection of epizootic hemorrhagic disease virus (EHDV) in clinical samples with different virus isolation (VI) procedures. Thirty-six blood samples and 1 spleen sample from deer were assessed by the EHDV PCR assay and VI in baby hamster kidney (BHK)-21 cells and embryonated chicken eggs (ECE). The EHDV PCR assay detected EHDV RNA from 6 blood samples obtained from deer during 1988–1989 outbreaks of epizootic hemorrhagic disease and from the spleen and blood samples of a deer with clinical hemorrhagic disease in 1992. The 6 blood samples from the 1988–1989 outbreaks and the spleen sample from the 1992 case were VI positive on BHK-21 cell culture. The blood from the same deer with the PCR- and VI-positive spleen was VI negative in BHK-21 cells and ECE. All EHDV isolates were identified as EHDV serotype 2 by a plaque inhibition test. The results of this study indicate that the sensitivity of the previously described EHDV PCR assay is comparable to or greater than that of the VI method in BHK-21 cell culture or ECE. The EHDV PCR assays could provide a superior diagnostic alternative to the current cumbersome and time-consuming VI procedures.

Testing of Male Sockeye Salmon (Oncorhynchus nerka) and Steel head Trout (Salmo gairdneri) for Infectious Hematopoietic Necrosis Virus

Infectious hematopoietic necrosis (IHN) virus has been isolated only rarely from whole milt samples of male sockeye salmon (Oncorhynchus nerka). In 3 yr of testing, virus incidences in males ranged from 0 to 13% when milt was sampled but were 60–100% with spleen or kidney. When IHN virus was isolated from sockeye salmon milt at titers less than 3.00 log10 plaque-forming units (pfu)/mL, the level of virus in the kidney or spleen exceeded 7.00 log10 pfu/g. Higher rates of IHN virus isolation from kidney or spleen than from milt were also generally found in steelhead trout (Salmo gairdneri), although the differences were less pronounced than in sockeye salmon. Furthermore, virus was sometimes isolated from steelhead trout milt when the level of virus in kidney or spleen samples was very low, and was recovered from some milt samples when none was isolated from the corresponding spleen sample. When male salmonids are tested for IHN virus, kidney or spleen samples are superior to whole milt, but milt should be included for critical examinations.