Severe oral infection due to Lactobacillus rhamnosus during induction chemotherapy for acute myeloid leukemia

We report a case of severe oral infection with a high fever due to Lactobacillus rhamnosus during induction chemotherapy for acute myeloid leukemia. The patient did not improve on treatment with meropenem, clindamycin, or vancomycin until neutrophil recovery. Since L. rhamnosus GG is used in dairy products, and the patient ingested dairy products daily before starting chemotherapy, we suspected an association between the ingestion of dairy products and the development of infection. Pulsed-field gel electrophoresis using two different restriction enzymes showed that the strain isolated from the patient was identical to the L. rhamnosus GG strain isolated from dairy products and ATCC #53103. This was confirmed by a PCR assay with species-specific L. rhamnosus GG primers. Since Lactobacillus infection, particularly L. rhamnosus infection, can be fatal in immunocompromised hosts, we should consider Lactobacillus as a causative organism when Gram-positive rods are detected during treatment with broad-spectrum antibiotics and vancomycin. The causal association between the ingestion of dairy products containing Lactobacillus and Lactobacillus infection in immunocompromised hosts warrants further study.

The Ca(2+) /calmodulin-dependent kinase kinase β-AMP-activated protein kinase-α1 pathway regulates phosphorylation of cytoskeletal targets in thrombin-stimulated human platelets

BACKGROUND

Platelet activation requires sweeping morphologic changes, supported by contraction and remodeling of the platelet actin cytoskeleton. In various other cell types, AMP-activated protein kinase (AMPK) controls the phosphorylation state of cytoskeletal targets.

OBJECTIVE

To determine whether AMPK is activated during platelet aggregation and contributes to the control of cytoskeletal targets.

RESULTS

We found that AMPK-α1 was mainly activated by thrombin, and not by other platelet agonists, in purified human platelets. Thrombin activated AMPK-α1 ex vivo via a Ca(2+) /calmodulin-dependent kinase kinase β (CaMKKβ)-dependent pathway. Pharmacologic inhibition of CaMKKβ blocked thrombin-induced platelet aggregation and counteracted thrombin-induced phosphorylation of several cytoskeletal proteins, namely, regulatory myosin light chains (MLCs), cofilin, and vasodilator-stimulated phosphoprotein (VASP), three key elements involved in actin cytoskeletal contraction and polymerization. Platelets isolated from mice lacking AMPK-α1 showed reduced aggregation in response to thrombin, and this was associated with defects in MLC, cofilin and VASP phosphorylation and actin polymerization. More importantly, we show, for the first time, that the AMPK pathway is activated in platelets of patients undergoing major cardiac surgery, in a heparin-sensitive manner.

CONCLUSION

AMPK-α1 is activated by thrombin in human platelets. It controls the phosphorylation of key cytoskeletal targets and actin cytoskeletal remodeling during platelet aggregation.

A combination of fludarabine, half-dose cyclophosphamide, and anti-thymocyte globulin is an effective conditioning regimen before allogeneic stem cell transplantation for aplastic anemia

Conditioning regimens consisting of reduced-dose cyclophosphamide (CY) and fludarabine (FDR) have been investigated for use in allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients with aplastic anemia to reduce the toxicities associated with CY. However, the ideal dose of CY has not been identified. In addition, little information is available regarding donor cell chimerism after allo-HSCT with these regimens. Therefore, we retrospectively analyzed 13 patients who underwent allo-HSCT with half-dose CY (100 mg/kg in total), FDR, and anti-thymocyte globulin at total doses of 2.5-10 mg/kg at our center. All the patients except one, who died due to encephalopathy on day 20, achieved neutrophil engraftment a median of 18.5 days after HSCT with complete donor-type chimerism. Two patients who received a graft from an HLA-matched donor subsequently developed mixed chimerism (MC) associated with transfusion-dependent cytopenia. One became transfusion-independent after donor lymphocyte infusion, but continues to exhibit MC. The other regained complete donor-type chimerism after the cessation of cyclosporine, but remains transfusion-dependent. These findings suggest that a conditioning regimen with half-dose CY and FDR is effective for achieving neutrophil engraftment and complete donor-type chimerism. However, subsequent MC may be observed, especially after HLA-matched HSCT.

Impact of high-/middle-molecular-weight adiponectin on the synthesis and regulation of extracellular matrix in dermal fibroblasts

Adiponectin has been shown to play a critical role in immunity. Recently, we reported that the adiponectin levels after allogeneic stem cell transplantation were higher in recipients with chronic graft-versus-host disease (cGVHD). However, the effects of adiponectin on extracellular matrix (ECM) and regulatory factors in dermal fibroblasts remain unclear. We compared the messenger RNA (mRNA) levels of collagen type1 (COL1A), fibronectin 1 (FN1), matrix metalloproteinase (MMP)1, MMP3, tissue inhibitor of metalloproteinase (TIMP)1, TIMP3, transforming growth factor-β (TGF-β), and TGF-β receptor 2 (TGF-βR2) in human normal dermal fibroblasts cultured with and without adiponectin, and we assessed the degree of synthesis of ECMs by immunofluorescent microscopy. Furthermore, we also assessed these mRNA levels after blocking of TGF-βR2. Adiponectin induced higher mRNA levels of FN1, MMP1, MMP3, TIMP1, TIMP3, and TGF-βR2 in a dose-dependent manner, but did not significantly affect COL1A or TGF-β. In addition, adiponectin was shown to upregulate FN1, MMPs, and TIMPs after blocking of TGF-βR2. Immunofluorescent microscopy revealed that adiponectin promoted a greater synthesis of ECMs than in the control in vitro. The finding that adiponectin upregulated ECM-associated factors might mean that high levels of adiponectin could modulate dermal fibrosis was observed in recipients with cGVHD. Further basic investigation is warranted to elucidate whether the adiponectin-pathway could be a target for the treatment of sclerotic cGVHD.

D-index dose not predict the development of pulmonary infection in acute myeloid leukemia patients undergoing consolidation chemotherapy with high-dose cytarabine

The D-index is calculated as the area over the neutrophil curve during neutropenia. We investigated the impact of the D-index on pulmonary infection in 33 acute myeloid leukemia patients undergoing consolidation chemotherapy with high-dose cytarabine. There was no difference in the D-index between chemotherapies with and without pulmonary infection. The cumulative D-index (c-D-index) until the development of infection exceeded 4000 in four of five patients with pulmonary infection. Although there was no difference in the total D-index throughout the overall consolidation chemotherapy, the total D-index from induction to consolidation and the D-index at induction chemotherapy were higher in patients with pulmonary infection during consolidation than in those without it (P = 0.014 and 0.019, respectively). Our results showed that the cumulative effect of neutropenia might determine the risk of pulmonary infection in consolidation chemotherapy. We are planning a clinical trial of c-D-index-guided preemptive antifungal therapy.

The safety and efficacy of acute graft-versus-host disease prophylaxis with a higher target blood concentration of cyclosporine around 500 ng/mL

Cyclosporine (CsA) is the most widely used immunosuppressive agent for the prevention of acute graft-versus-host disease (GVHD). In a previous report, the incidence of acute GVHD was decreased by increasing the target blood concentration of CsA during a continuous infusion from 300 to 500 ng/mL without excessive toxicities. To confirm these results, we retrospectively analyzed 69 patients who received a continuous infusion of CsA at a higher target CsA level between 450 and 550 ng/mL (CsA500 group) and compared the clinical outcome with 29 patients who received CsA with a lower target concentration between 250 and 350 ng/mL (CsA300 group). The target concentration was determined based on the status of background diseases. Multivariate analysis revealed that the incidence of grade III-IV acute GVHD was significantly lower in the CsA500 group, although the incidence of grade II-IV acute GVHD was not different. Toxicities were equivalently observed between the two groups. Concomitant administration of voriconazole or itraconazole and higher hematocrit were identified as independent significant factors for higher concentration/dose ratio of CsA. The average dose of CsA to maintain CsA level around 500 ng/mL was higher compared with the previous study (3.4 mg/kg vs. 2.7 mg/kg at three wk), probably due to the difference in measuring method of CsA concentration. We conclude that continuous infusion of CsA with a target level between 450 and 550 ng/mL is a feasible and effective GVHD prophylaxis, but caution should be paid for the difference in measuring method.

Evaluation of the validity of preemptive therapy against cytomegalovirus disease based on antigenemia assay with a cutoff of 20 positive cells per two slides

Background

Preemptive therapy with ganciclovir (GCV) based on the results of a cytomegalovirus (CMV) antigenemia assay is a standard strategy for preventing CMV disease after allogeneic hematopoietic cell transplantation (HCT). However, the appropriate threshold of antigenemia-positive cells for deciding when to start GCV remains unclear.

Patients

This retrospective study included 80 recipients who received HCT from an alternative donor between 2007 and 2011. In 2009, we switched the threshold from 3 (3A group, n=24) to 20 (20A group, n=56) antigenemia-positive cells per two slides for preemptive therapy after HCT from an alternative donor.

Results

Early CMV disease within 100 days after HCT was observed in one patient in the 20A group. Antiviral agents including GCV, val-GCV, and foscarnet were given in 17 (71%) and 36 (64%) patients in the 3A and 20A groups, respectively (p=0.23). In 13 (23%) patients in the 20A group, the initiation of preemptive therapy was avoided because of the change in the cutoff value for CMV antigenemia. However, the total dose of GCV was not different between the two groups. The use of steroid was significantly associated with CMV antigenemia of at least 20 positive cells among patients with low-level antigenemia at the first detection.

Conclusion

The increased threshold up to 20 positive cells for starting preemptive therapy was not associated with a significant increase in CMV disease, but the total dose of GCV was not reduced and there was one early CMV disease in the 20A group. We should explore how to identify patients who are at high risk for increased antigenemia among patients with low-level antigenemia, but at least, preemptive therapy should not be withheld in patients who are already receiving systemic steroid.

Low-dose acyclovir prophylaxis for the prevention of herpes simplex virus disease after allogeneic hematopoietic stem cell transplantation

BACKGROUND

Currently, acyclovir (ACV) at 1000 mg/day is widely used as prophylaxis in the early phase of hematopoietic stem cell transplant (HSCT) in Japan. However, low-dose ACV (200 mg/day) has been shown to prevent varicella zoster virus reactivation in the middle and late phases of HSCT.

METHODS

Therefore, in this study, we decreased the dose of ACV to 200 mg/day in the early phase after HSCT. We analyzed 93 consecutive herpes simplex virus (HSV)-seropositive patients who underwent allogeneic HSCT for the first time in our center between June 2007 and December 2011.

RESULTS

Before August 2009, 38 patients received oral ACV at 1000 mg/day (ACV1000) until day 35 after HSCT, whereas 55 patients received oral ACV at 200 mg/day (ACV200) after September 2009. We compared the cumulative incidence of HSV infection in the 2 groups. Oral ACV was changed to intravenous administration because of intolerance in 66% and 45% of the patients in the ACV1000 and ACV200 groups, respectively (P = 0.060). The probability of severe stomatitis (Bearman grade II-III) was 76% and 60% in the ACV1000 and ACV200 groups, respectively (P = 0.12). The number of patients who developed HSV disease before day 100 after HSCT was 0 in the ACV1000 group and 2 in the ACV200 group, with a cumulative incidence of 3.6% (P = 0.43). HSV disease in the latter 2 patients was limited to the lips and tongue and was successfully treated with ACV or valacyclovir at a treatment dose.

CONCLUSION

ACV at 200 mg/day appeared to be effective for preventing HSV disease in the early phase after HSCT.

Protection of ovarian function by two distinct methods of ovarian shielding for young female patients who receive total body irradiation

To prevent ovarian dysfunction due to total body irradiation, we started ovarian shielding at our center (Saitama Medical Center, Jichi Medical University (SMC-JMU)) with a long source axis distance, which is different from the original method used at the University of Tokyo Hospital (UTH). We retrospectively analyzed the outcome of eight patients with a median age of 20.5 years from SMC-JMU and compared the results with the published data for eight patients with a median age of 22 years from UTH. The recovery of ovarian function was observed in five and six patients, respectively. The cumulative incidence of ovarian recovery, while treating relapse and death without ovarian recovery as competing risks, was 68.8 % at 2 years after transplantation in the total population, and there was no statistically significant difference between the two institutions (p = 0.85). Age and the history of previous chemotherapy did not affect the incidence of ovarian recovery. Two patients from each center had a relapse of leukemia. Overall, among the 11 patients who have survived without relapse, only one has not achieved ovarian recovery. In conclusion, ovarian shielding with both methods strongly protected ovarian function. However, we should continue to monitor the relapse rate among patients who undergo this procedure.

Acquired factor V inhibitor associated with life-threatening bleeding and a mixing test result that indicated coagulation factor deficiency

A mixing test is useful for distinguishing between coagulation factor deficiency and the presence of inhibitor as the cause of coagulopathy. However, we experienced a patient with acquired factor V (FV) inhibitor whose mixing test showed a coagulation factor deficiency pattern. A 65-year-old man with a tendency for bleeding was referred to our center. The laboratory data showed remarkable prolongation of prothrombin time and activated partial thromboplastin time (APTT). FV activity was less than 3%. A mixing test showed a coagulation factor deficiency pattern. However, neither the tendency for bleeding nor the coagulation tests were corrected by transfusion of fresh frozen plasma. A few days later, a positive test for FV inhibitor of 3 Bethesda units was obtained. Therefore, we started prednisolone and plasma exchange, and the coagulation test results normalized after 6 weeks. Although an incubation period is generally not considered necessary in a mixing test for FV inhibitor, we repeated mixing tests with various incubation periods and confirmed an incubation period-dependent prolongation of the APTT. Therefore, a mixing test with an incubation period is recommended for the detection of FV inhibitor, since a mixing test without an incubation period may show a coagulation factor deficiency pattern when the titer of FV inhibitor is low.

Allotype analysis to distinguish the origin of varicella-zoster virus immunoglobulin G after allogeneic stem cell transplantation

Varicella-zoster virus (VZV) reactivation is a frequent complication after allogeneic hematopoietic stem cell transplantation (HSCT). Although previous studies have revealed that cellular immunity is important for suppressing reactivation, the role of humoral immunity against VZV has been poorly evaluated. We analyzed inherited polymorphisms in the immunoglobulin G (IgG) heavy chain constant regions of 50 HSCT recipient-donor pairs to distinguish donor-derived and recipient-derived antibodies. Twelve pairs were informative regarding the origin of IgG, since either the donors (n = 3) or recipients (n = 9) were homozygous null for the IgG1m(f) allotype. In these 9 homozygous-null recipients, allotype-specific IgG against VZV were measured by enzyme-linked immunosorbent assay and compared with measles-IgG. All 9 homozygous-null recipients were monitored for more than 1 year after HSCT, with (n = 4, localized zoster) or without (n = 5) clinical VZV disease. In 3 patients with VZV disease, donor-derived IgG against VZV was elevated between 500 to 700 days after HSCT after the episode of VZV disease. In 1 patient who suffered from VZV disease just before HSCT, donor-derived VZV IgG was elevated within 3 months after HSCT. On the other hand, 2 patients who received reduced-intensity conditioning (RIC) transplantation from an IgG1m(f) null donor maintained recipient-derived IgG against VZV for more than 1 year, whereas it was decreased within 3 months in 1 recipient who received conventional conditioning. In conclusion, the production of anti-VZV IgG by recipient plasma cells persists long after RIC. In patients without symptomatic VZV reactivation, donor-derived anti-VZV IgG did not reach titers comparable to those measured in healthy virus carriers.

Sulfide induces apoptosis and Rho kinase-dependent cell blebbing in Jurkat cells

Hydrogen sulfide (H₂S) is a toxic gaseous substance, and accidental exposure to high concentrations of H₂S has been reported to be lethal to humans. Inhaled and absorbed H₂S is partially dissolved within the circulation and causes toxic effects on lymphocytes. However, the mechanisms involved in H₂S toxicity have not been well documented. In this study, we examined the cellular uptake and injury of sulfide-exposed human T lymphocytes (Jurkat). Cells were exposed to a H₂S donor, sodium hydroxysulfide (NaHS), at pH 6.0, 7.0, or 8.0 for 1 h at 37 °C in a sealed conical tube to avoid the loss of dissolved H₂S gas. Cytotoxicity and cellular sulfide concentrations increased dramatically as the pH of the NaHS solution decreased. Sulfide enhanced the cleavage of caspase-3 and poly (ADP-ribose) polymerase and induced early cellular apoptosis. A pan-caspase inhibitor reduced sulfide-induced apoptosis. These results indicate that sulfide induces pH-dependent and caspase-dependent apoptosis. We also found that blebbing of the plasma membrane occurred in sulfide-exposed cells. Both ROCK-1 and ROCK-2 (Rho kinases) were activated by sulfide, and sulfide-induced cell blebbing was suppressed by a ROCK inhibitor, suggesting that a Rho pathway is involved in sulfide-induced blebbing in lymphocytes.

Minocycline selectively inhibits M1 polarization of microglia

Minocycline is commonly used to inhibit microglial activation. It is widely accepted that activated microglia exert dual functions, that is, pro-inflammatory (M1) and anti-inflammatory (M2) functions. The in vivo status of activated microglia is probably on a continuum between these two extreme states. However, the mechanisms regulating microglial polarity remain elusive. Here, we addressed this question focusing on minocycline. We used SOD1^G93A mice as a model, which exhibit the motor neuron-specific neurodegenerative disease, amyotrophic lateral sclerosis. Administration of minocycline attenuated the induction of the expression of M1 microglia markers during the progressive phase, whereas it did not affect the transient enhancement of expression of M2 microglia markers during the early pathogenesis phase. This selective inhibitory effect was confirmed using primary cultured microglia stimulated by lipopolysaccharide (LPS) or interleukin (IL)-4, which induced M1 or M2 polarization, respectively. Furthermore, minocycline inhibited the upregulation of NF-κB in the LPS-stimulated primary cultured microglia and in the spinal cord of SOD1^G93A mice. On the other hand, IL-4 did not induce upregulation of NF-κB. This study indicates that minocycline selectively inhibits the microglia polarization to a proinflammatory state, and provides a basis for understanding pathogeneses of many diseases accompanied by microglial activation.

Living donor liver transplantation from an asymptomatic mother who was a carrier for ornithine transcarbamylase deficiency

Liver transplantation (LT) has been adopted as a radical treatment for ornithine transcarbamylase deficiency (OTCD), yielding favorable outcomes. Despite the fact that it is an inheritable disease, a blood relative who is heterozygous for the disorder must sometimes be used as a liver donor for living donor LT. There is ongoing discussion regarding the use of heterozygous donors, however, to our knowledge, no cases where donation was determined based on the Ornithine transcarbamylase (OTC) activity before LT have been reported. Between May 2001 and April 2011, 17 patients were indicated for living donor LT because of OTCD at our facility. There were three cases with heterozygous donor candidate (17.6%). All heterozygous candidates underwent a liver biopsy to measure their OTC activity before LT and made efforts to secure the safety of the both donor and recipient. Two of 3 candidates had headaches sometimes, and their activity was less than 40%, and thus they were not employed as the donor. One candidate with 104.4% activity was employed, yielding favorable outcomes. Our current experience supported the effectiveness of our donation criteria, however it is necessary to collect sufficient data on a large number of patients to confirm the safety of the procedure.

Long-term persistence of limited HTLV-I Tax-specific cytotoxic T cell clones in a patient with adult T cell leukemia/lymphoma after allogeneic stem cell transplantation

PURPOSE

Adult T cell leukemia/lymphoma (ATL) is a highly aggressive malignancy of T cells caused by human T cell lymphotropic virus type 1 (HTLV-1). Recent clinical studies have suggested that allogeneic stem cell transplantation (HSCT) improves the clinical course of ATL by harnessing a graft-versus-ATL effect, and that donor-derived HTLV-1 Tax-specific CD8(+) cytotoxic T cells (CTLs) contribute to the graft-versus-ATL effect after HSCT. However, little is known about the immunological characteristics of Tax-specific CTLs in ATL patients who underwent HSCT.

METHODS

We serially analyzed frequencies, differentiation, functions and clonal dynamics of Tax-specific CTLs in paired samples of peripheral blood (PB) and bone marrow (BM) from an ATL patient after HSCT at the single-cell level. We used flowcytometric and single-cell T cell receptor (TCR) repertoire analysis methods without culture steps.

RESULTS

Donor-derived Tax-specific CTLs effectively suppressed HTLV-1 replication in both PB and BM at least during chronic graft-versus-host disease after HSCT. Furthermore, Tax-specific CTLs had comparable properties between BM and PB, except for preferential accumulation in BM rather than PB. Tax-specific CTLs persistently existed as less-differentiated CD45RA(-)CCR7(-) effector memory CTLs based on predominant phenotypes of CD27(+), CD28(+/-) and CD57(+/-). Our approach using single-cell TCR repertoire analysis method showed highly restricted oligoclonal responses of Tax-specific CTLs, and TCR BV7- or BV30- expressing two predominant CTL clones persistently existed and maintained strong cytotoxic activities against HTLV-1 in both PB and BM over three years after HSCT.

CONCLUSIONS

These findings about Tax-specific CTLs provide insights into future directions for studies on immunotherapy against ATL.

Hyperbilirubinemia in the early phase after allogeneic HSCT: prognostic significance of the alkaline phosphatase/total bilirubin ratio

Hyperbilirubinemia in the early phase after allogeneic hematopoietic SCT (HSCT) is due to various causes. One of the most important causes of hyperbilirubinemia is veno-occlusive disease/sinusoidal obstructive syndrome (VOD/SOS). However, the prognosis of patients who are clinically diagnosed as SOS varies. We retrospectively evaluated 82 patients who underwent their first allogeneic HSCT. GVHD prophylaxis was a combination of short-term MTX and CsA (n=77) or tacrolimus (n=5). Thirty-three patients developed hyperbilirubinemia, with a bilirubin level of at least 2 mg/dL, within 20 days after HSCT. Of these patients, 24 were diagnosed as VOD/SOS using the modified Seattle criteria. Twenty-six recovered to a bilirubin level of <2 mg/dL. We focused on the serum alkaline phosphatase/total bilirubin ratio (ALP/TB) at the onset of hyperbilirubinemia and found that it significantly predicted the recovery from hyperbilirubinemia. OS was significantly higher in patients with a lower ALP/TB ratio (P=0.00056). In addition, a lower ALP/TB ratio was associated with better survival even in patients who were clinically diagnosed as SOS (P<0.001). The ALP/TB ratio at the onset of hyperbilirubinemia may be a useful predictor for the prognosis of hyperbilirubinemia and SOS early after HSCT.

[Surgical management of visceral heterotaxy syndrome]

Surgical management of the heterotaxy syndrome including asplenia or polysplenia is still challenging, because they have not only congenital heart defects but also gastrointestinal abnormalities. In most cases, they are Fontan candidates, however, indications and procedures of surgical strategy toward Fontan operation are quite difficult because of cardiac complications or abdominal manifestations. We mentioned indications, surgical technique, peri- and post-operative managements of asplenia syndrome with our experiences and results.