Acute kidney injury after myeloablative cord blood transplantation in adults: the efficacy of strict monitoring of vancomycin serum trough concentrations

BACKGROUND

Acute kidney injury (AKI) is a common medical complication after myeloablative allogeneic stem cell transplantation (SCT). We have previously performed a retrospective analysis of AKI after cord blood transplantation (CBT) in adults, and found that the maximum of vancomycin (VCM) trough levels were significantly higher in patients with AKI. Following these results, we have monitored VCM serum trough concentrations more strictly, to not exceed 10.0 mg/L, since 2008.

METHODS

In this report, we performed an analysis of AKI in a new group of 38 adult patients with hematological malignancies treated with unrelated CBT after myeloablative conditioning between January 2008 and July 2011.

RESULTS

Cumulative incidence of AKI at day 100 after CBT was 34% (95% confidence interval 19-50). The median of the maximum value of VCM trough was 8.8 (4.5-12.2) mg/L. In multivariate analysis, no factor was associated with the incidence of AKI. No transplant-related mortality was observed. The probability of disease-free survival at 2 years was 83%.

CONCLUSION

These findings suggest that strict monitoring of VCM serum trough concentrations has a beneficial effect on outcomes of CBT.

The role of adrenomedullin in the renal NADPH oxidase and (pro)renin in diabetic mice

Adrenomedullin has an antioxidative action and protects organs in various diseases. To clarify the role of adrenomedullin in diabetic nephropathy, we investigated the NADPH oxidase expression, renin-secreting granular cell (GC) hyperplasia, and glomerular matrix expansion in the streptozotocin (STZ)-induced diabetic adrenomedullin gene knockout (AMKO) mice compared with the STZ-diabetic wild mice at 10 weeks. The NADPH oxidase p47phox expression and lipid peroxidation products were enhanced in the glomeruli of the diabetic mice compared with that observed in the controls in both wild and AMKO mice. These changes were more obvious in the AMKO mice than in the wild mice. Glomerular mesangial matrix expansion was more severe in the diabetic AMKO mice than in the diabetic wild mice and exhibited a positive correlation with the degree of lipid peroxidation products in the glomeruli. Proteinuria was significantly higher in the diabetic AMKO mice than in the diabetic wild mice. The GC hyperplasia score and the renal prorenin expression were significantly increased in the diabetic AMKO mice than in the diabetic wild mice, and a positive correlation was observed with the NADPH oxidase expression in the macula densa. The endogenous adrenomedullin gene exhibits an antioxidant action via the inhibition of NADPH oxidase probably by suppressing the local renin-angiotensin system.

A case of de novo focal segmental glomerulosclerosis occurred one and half years after kidney transplantation supposed to be caused by calcineurin inhibitor

A 64-yr-old man with end-stage kidney disease caused by hypertensive nephrosclerosis underwent living-unrelated ABO-identical kidney transplantation (KTx) at the age of 60 yr from his 60-yr-old wife. Maintenance trough concentration of cyclosporine A (CsA) was 100 ± 30 ng/mL. Five months after KTx, proteinuria gradually increased to around 1 g/d. TRBx at eight months after KTx revealed the new-onset alteration of mild arteriolosclerosis with intimal hyalinosis, which might reflect calcineurin inhibitor (CNI)-associated arteriopathy (CAA). Nearly one and half years after KTx, urinary protein excretion became nearly 2 g/d. TRBx revealed the advanced CAA and findings of focal segmental glomerulosclerosis (FSGS). Then, CNI was switched from CsA to tacrolimus (TAC). TRBx at two and half years after KTx revealed progressed arteriolar transmural thickening and striped fibrosis, which were supposed to be induced by an increase in serum TAC concentration because of acute enterocolitis. Then, TAC dose was reduced to serum trough concentration 5-8 ng/mL, but urinary protein excretion was increased up to 10 g/d. Reduction of TAC to trough concentration 2.0 ± 0.5 ng/mL reduced urinary protein excretion. Attempts to elevate TAC trough concentration within normal range (4-8 ng/mL) reproducibly induced the recurrence of an increase in sCr or urinary protein excretion. All these findings supported the etiology of graft dysfunction, and proteinuria of this case was FSGS.

Dissolution and Degradation of Bacillus thuringiensis delta-Endotoxin by Gut Juice Protease of the Silkworm Bombyx mori

The dissolution and degradation of dagger-endotoxin (crystal) of Bacillus thuringiensis subsp. kurstaki strain HD-1 were investigated. Crystals were dissolved in 0.1 M phosphate-carbonate-NaOH buffer at pH > 12. Swelling of crystals occurred in the buffer between pH 10 and 11, and crystals dissolved in the same buffer supplemented with gut juice protease of the silkworm Bombyx mori. The proteolytic dissolution of crystals occurred after a time lag of several minutes in 0.1 M carbonate-NaOH buffer, pH 10.2. The time lag was not observed when crystals were suspended in the buffer for 30 min before the addition of protease. After the dissolution of the crystals and further degradation of the solubilized protein, the appearance of a toxic protein with a molecular weight of 59,000, designated P-59, was observed. Lower-molecular-weight peptides (less than 40,000) showed no toxicity to the silkworm larvae on feeding. Digestion of the 120,000-dalton subunit of the crystal by gut juice protease also produced P-59. These observations suggest the occurrence of a similar process in vivo, i.e., the swelling of crystals due to the alkalinity of gut juice and the production of P-59, dependent on the hydrolysis of swollen crystals by gut juice protease.

Gene set enrichment analysis provides insight into novel signalling pathways in breast cancer stem cells

Background:

Tumour-initiating cells (TICs) or cancer stem cells can exist as a small population in malignant tissues. The signalling pathways activated in TICs that contribute to tumourigenesis are not fully understood.

Methods:

Several breast cancer cell lines were sorted with CD24 and CD44, known markers for enrichment of breast cancer TICs. Tumourigenesis was analysed using sorted cells and total RNA was subjected to gene expression profiling and gene set enrichment analysis (GSEA).

Results:

We showed that several breast cancer cell lines have a small population of CD24^−/low/CD44⁺ cells in which TICs may be enriched, and confirmed the properties of TICs in a xenograft model. GSEA revealed that CD24^−/low/CD44⁺ cell populations are enriched for genes involved in transforming growth factor-β, tumour necrosis factor, and interferon response pathways. Moreover, we found the presence of nuclear factor-κB (NF-κB) activity in CD24^−/low/CD44⁺ cells, which was previously unrecognised. In addition, NF-κB inhibitor dehydroxymethylepoxyquinomicin (DHMEQ) prevented tumourigenesis of CD24^−/low/CD44⁺ cells in vivo.

Conclusion:

Our findings suggest that signalling pathways identified using GSEA help to identify molecular targets and biomarkers for TIC-like cells.

Autopsy report on pseudo-Bartter syndrome with renal calcification induced by diuretics and diet pills

A woman in her mid-forties had repeated vomiting and diarrhoea accompanied by muscle weakness soon after she started taking seven different diet pills imported from Thailand. After she had taken the pills for 8 days, respiratory depression progressed rapidly to arrest. Blood tests at the Emergency Department showed severe hypokalaemia with metabolic alkalosis. We diagnosed that she had developed pseudo-Bartter syndrome from the findings based on ionic abnormalities and high renin and aldosterone levels, and hyperplasia of the juxtaglomerular apparatus. A postmortem blood analysis indicated subtherapeutic levels of furosemide. We concluded that the patient died from pseudo-Bartter syndrome, which was triggered by chronic self-administration of furosemide and aggravated by the diet pills. This is the first pseudo-Bartter syndrome autopsy report to show histological localisation of calcification in the kidneys.

Long-term renal prognosis of IgA nephropathy with therapeutic trend shifts

OBJECTIVE

We compared the effect of treatments in the long-term renal survival of IgA nephropathy.

METHODS

One hundred and fourteen patients with biopsy-proven IgA nephropathy were retrospectively divided into 4 groups, reflecting shifts in treatment trends from 1985 to 2005: patients without treatment (no treatment group; n=36), patients treated only with anti-platelet drugs (anti-platelet group; n=12), those treated mainly with angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) (ACEI/ARB group; n =29), and prednisolone-treated patients (PSL group; n =37).

RESULTS

Baseline blood pressure, serum creatinine and renal histological findings were similar among the 4 groups; however, the urinary protein level was significantly severer in the PSL group. After a mean follow-up of 7.0+/-0.5 years, end-stage renal disease occurred in 11 patients (31%) in the no treatment group, 5 patients (42%) in the anti-platelet group and 3 patients (8%) in the PSL group, but in only 1 patient (3%) in the ACEI/ARB group. Kaplan-Meier renal survival after 20 years was significantly better in the ACEI/ARB group than in the anti-platelet group or in the no treatment group (p<0.05). The patients that reached complete remission (CR) by steroid therapy showed less baseline urinary protein and milder histological lesions than those who did not reach CR. The non-CR group showed increases in serum creatinine and eGFR reduction rate.

CONCLUSION

Treatment with renin-angiotensin system inhibitors showed the greatest improvement of 20-year renal survival in IgA nephropathy patients. Steroid therapy achieved complete remission in some early-stage cases.

Unrelated cord blood transplantation after myeloablative conditioning in adults with ALL

We analyzed the disease-specific outcomes of adult ALL treated with cord blood transplantation (CBT) after myeloablative conditioning. Between October 2000 and November 2007, 27 adult patients with ALL were treated with unrelated CBT. All patients received four fractionated 12 Gy TBI and chemotherapy as myeloablative conditioning. The median age was 36 years, the median weight was 57 kg and the median number of nucleated cells was 2.47 x 10(7)/kg. All patients received a single and HLA-mismatched cord blood unit. The cumulative incidence of neutrophil recovery at day 30 and platelet recovery at day 200 was 92.6 and 92.3%, respectively. With a median follow-up of 47 months, the probability of EFS at 5 years was 57.2%. The 5-year cumulative incidence of TRM and relapse was 3.7 and 27.4%, respectively. These results suggest that unrelated CBT after myeloablative conditioning could be safely and effectively used for adult patients with ALL.

Glomerular albumin filtration through podocyte cell body in puromycin aminonucleoside nephrotic rat

It is an a priori concept that protein molecules including albumin are filtrated through the slit membrane between the foot processes of podocytes. However, foot processes are effaced and the number of slit membranes is reduced in nephrotic syndrome, suggesting another pathway of albumin filtration through the foot process cell body. Thus, we investigated the pathway of gold-and fluorescein isothiocyanate (FITC)-labeled albumin filtration in the puromycin aminonucleoside (PAN) model of nephrotic syndrome in the rat. PAN rats at day 7 with established nephrotic proteinuria were injected with 8-nm gold-labeled albumin and FITC-labeled albumin through the jugular vein followed by kidney fixation at 10 or 30 min. Goldlabeled albumin was accumulated in the paramesangial area and in the endosomes of glomerular endothelial cells of both control and PAN rats by electron microscopy. On the other hand, FITC-labeled albumin was detected between foot processes in the control but more in the podocyte cell body in the PAN rat. In conclusion, albumin will be filtrated through the decreased numbers of slit diaphragms; however, albumin can be also taken up in the podocyte, the mesangium, and the glomerular endothelium, suggesting that there might be other routes of glomerular albumin clearance in nephrotic syndrome.

No occurrence of Pneumocystis jiroveci (carinii) pneumonia in 120 adults undergoing myeloablative unrelated cord blood transplantation

The incidence of pneumonia caused by Pneumocystis carinii (PCP) (organism now renamed Pneumocystis jiroveci) during the early period after cord blood transplantation (CBT) was studied in 120 adults. Initially 89 patients (74%) received oral administration of 2 single-strength trimethoprim-sulfamethoxazole (TMP-SMZ) tablets twice daily from day -21. In 45 of 89 patients (51%), TMP-SMZ administration for a scheduled duration was completed. In the remaining 44 patients (49%), however, TMP-SMZ administration was discontinued prior to day -3 because of toxicity. Among these patients, 42 subsequently received aerosolized pentamidine (AP) on a median of day -13 (range, -20 to -6). Thirty-one patients (26%) received AP without TMP-SMZ administration on a median of day -14 (range, -21 to -9). None of the 120 patients were diagnosed with PCP within 100 days or 2 years after CBT; however, one patient who received AP before CBT but no prophylaxis after CBT developed cerebral toxoplasmosis on day +91. Pre-transplant prophylaxis against PCP did not significantly affect transplantation-related mortality or disease-free survival at 2 years after CBT. The results suggest that PCP during the early period after CBT can be effectively prevented by any pre-transplant prophylactic method.