[Atypical mycobacterial infection after kidney transplant: two clinical cases]

Infections are an important cause of morbidity and mortality during kidney transplant. In areas where tuberculosis is not endemic, Mycobacteria other than tuberculosis (MOOT), also known as 'atypical' Mycobacteria, are more frequently involved in mycobacterial infections than M. tuberculosis. The incidence of MOOT infection in renal transplant recipients ranges from 0.16 to 0.38 percent. This low rate of reported incidence is, however, often due to delay in diagnosis and lack of therapeutic protocols. Further difficulty is caused by the interaction of antimycobacterial drugs with the post-transplant immunosuppressive regimen, necessitating close monitoring of plasma concentrations and careful dose modification. We present two cases of Mycobacterium Chelonae infection in kidney transplant recipients which differ in both clinical presentation and pharmacological approach.

[Diverse histological lesions in a patient with antiphospholipid syndrome (APS)]

Antiphospholipid syndrome (APS) is a rare autoimmune disorder. It can be secondary to systemic lupus erythematosus (SLE) or occur in the absence of autoimmune disease. The hallmark of this so-called primary APS is the presence of circulating antiphospholipid antibodies. Renal involvement in primary APS is caused by thrombosis within the renal vasculature. Recently, nonthrombotic glomerulonephritic renal lesions have been described in primary APS as a new histological entity. We here report a patient with primary APS in whom both lesion types were present. A 58-year-old Caucasian man with no significant past medical history presented to our nephrology unit with diffuse edema. Urinalysis showed proteinuria exceeding 400 mg/dL. The autoantibody panel (p-ANCA, c- ANCA, anti-nucleus, anti-DS-DNA) was negative except for anticardiolipin antibodies, which tested positive in two different samples. The diagnostic workup included a kidney biopsy that revealed thrombotic lesions compatible with primary APS and a typical pattern of focal segmental glomerulosclerosis. The kidney is a major target in APS but the exact mechanism underlying the pathogenesis of APS nephropathy has been poorly recognized. The use of kidney biopsy is a fundamental diagnostic tool in this setting, with possible implications also from a prognostic and therapeutic viewpoint.

Preoperative creatinine clearance as a predictor of short-term outcomes after cardiac surgery: a cohort study for the comparison between the Cockroft-Gault and modification of diet in renal disease formulae

BACKGROUND

Preoperative renal function is an important risk factor in cardiac surgery for long-term and short-term outcomes. Renal function is best assessed by measuring or calculating the glomerular filtration rate (GFR). Several algorithms using the endogenous marker serum creatinine have been developed to estimate renal function. These include the Cockcroft and Gault and the modification of diet in renal disease (MDRD) formulae. The aim of this study was to compare the predictive power of the two formulae towards short-term outcomes after cardiac surgery, such as the length of intensive care unit (ICU) stay, the length of mechanical ventilation time, and the length of in-hospital stay.

METHODS

One hundred and fifty patients undergoing cardiac surgery and not affected by renal failure were followed up until hospital discharge. We collected data before, during and after surgery. Before surgery data consisted of date of birth, sex, height, weight, plasma creatinine level; during surgery data consisted of type of intervention (including number of bypasses, if any), cardiopulmonary bypass time and aortic cross-clamp time; after surgery data consisted of length of ICU stay, mechanical ventilation time, length of in-hospital stay after intensive-care discharge (ward stay), incidence of acute renal failure (expressed as the need for dialysis) and mortality. The dataset was analyzed using Cox regression.

RESULTS

The average mechanical ventilation time, ICU stay and ward stay were 11 h, 49 h and 10 days, respectively. After having adjusted for chronic obstructive pulmonary disease, diabetes and postsurgical dialysis, the GFR calculated with the Cockcroft and Gault formula appeared to be a predictor of ICU stay and mechanical ventilation time with very strong evidence (P = 0.002 and <0.001, respectively) and a predictor of ward stay with some evidence (P = 0.062). After an identical case-mix adjustment, the GFR calculated with the MDRD formula appeared to be a predictor of ICU stay with strong evidence (P = 0.007), a predictor of mechanical ventilation time with some evidence (P = 0.075) and it has shown no evidence of predicting ward stay (P = 0.197).

CONCLUSION

There is an indication that the Cockcroft and Gault formula could be more powerful than the MDRD formula for the preoperative prediction of early postoperative clinical outcomes in cardiac surgery, in patients not affected by renal failure. Further research is needed to confirm this result.

Right ventricular dysfunction in patients with end-stage renal disease

BACKGROUND

While chronic dialysis treatment has been suggested to increase pulmonary pressure values, right ventricular dysfunction (RVD) is a major cause of death in patients with end-stage renal disease. We investigated the impact of different dialysis treatments on right ventricular function.

METHODS

We examined 220 subjects grouped as follows: healthy controls (n = 100), peritoneal dialysis (PD; n = 26), hemodialysis (HD) with radial arteriovenous fistula (AVF; n = 62), and HD with brachial AVF (n = 32). Echocardiography including tissue Doppler imaging (TDI) of the right ventricle was performed in all patients.

RESULTS

Pulmonary pressure values progressively rose from controls across the 3 dialysis groups (21.7 ± 6.8, 29.7 ± 6.7, 37.9 ± 6.7 and 40.8 ± 6.6 mm Hg, respectively; p < 0.001). TDI indices of right ventricular function were more impaired in HD patients, particularly in those with brachial AVF. RVD, assessed by TDI myocardial performance index, was higher in HD patients compared with PD patients (71.3 vs. 34.6%, p < 0.001). Moreover, the prevalence of RVD further increased in patients with brachial AVF compared with the radial access (90.6 vs. 61.3%, p < 0.001).

CONCLUSIONS

Compared to DP, HD increases the risk of RVD, particularly in the presence of brachial AVF. TDI may detect early functional failure of the right ventricle in HD patients.

Neutrophil gelatinase-associated lipocalin levels after use of mini-cardiopulmonary bypass system

Neutrophil gelatinase-associated lipocalin (NGAL) has been implicated as an early predictive urinary biomarker of ischemic acute kidney injury (AKI). The aim of this study was to compare the effects of miniaturized cardiopulmonary bypass system (MCPB) vs. standard cardiopulmonary bypass system (SCPB) system on kidney tissue in patients undergoing myocardial revascularization using urinary NGAL levels as an early marker for renal injury. Sixty consecutive patients who underwent myocardial revascularization were studied prospectively. An SCPB was used in 30 patients (group A) and MCPB was used in 30 patients (group B). The SCPB group but not the MCPB group showed a significant NGAL concentration increase from preoperative during the 1st postoperative day (169.0+/-163.6 ng/ml in the SCPB group vs. 94.1+/-99.4 ng/ml in the MCPB group, P<0.05, respectively). Two patients in the SCPB group developed AKI and underwent renal replacement therapy; no patient in MCPB developed AKI. The MCPB system is safe in routine clinical use. Kidney function is better protected during MCPB as demonstrated by NGAL levels. NGAL represents an early biomarker of renal failure in patients undergoing cardiac surgery and the valuation of its concentration can aid in medical decision-making.

Mild and moderate renal dysfunction: impact on short-term outcome

BACKGROUND

Preoperative renal dysfunction is an important risk factor in cardiac surgery. Thus, the association between creatinine clearance (ClCr) and mechanical ventilation time and ICU length of stay, independent of other established preoperative risk indicators, was analyzed.

METHODS

In our study, 156 consecutive patients underwent open-heart surgery at the Department of Cardiac Surgery, University Hospital St. Andrea, Rome, and were prospectively studied for the relation between the ClCr, using the formula develop by Cockroft and Gault, and ICU length of stay and mechanical ventilation time. The 156 patients were divided into two groups in relation of ClCr: group A (n=78) ClCr<70 ml/min; group B (n=78) ClCr>70 ml/min.

RESULTS

In multivariate analysis, ICU length of stay was influenced by ClCr<70 ml/min, hypertension and COPD. ICU stay was median 48 h (range 24-72) in group A versus 24h (range 20.7-44) in group B (p=0.0001). In multivariate analysis, only ClCr<70 ml/min and EuroScore were associated with increasing VAM. VAM was median 8h (range 5.7-13.2) in group A versus 6h (range 4-10) in group B (p=0.001).

CONCLUSIONS

Our study demonstrates that after short-term outcome follow-up, preoperative mild renal dysfunction is an independent predictor of ICU length of stay and mechanical ventilation time.

Intraoperative Veno-Arterial Hemofiltration During Miniaturized Extracorporeal Bypass

We report the case of a 71-year-old man with creatinine clearance of 41 mL/min and acute anterior ST-segment elevation who underwent urgent coronary artery bypass grafting. A continuous intraoperative veno-arterial hemofiltration with high volumes of exchange (35 mL/kg/h) was used in a series for a miniaturized extracorporeal bypass system to minimize the inflammatory response and to protect the kidneys of this patient who had preoperative renal dysfunction. The patient had an uneventful postoperative recovery.

Continuous renal replacement therapies: anticoagulation in the critically ill at high risk of bleeding

BACKGROUND

The ongoing necessity for systemic heparinization is a well-known disadvantage of continuous renal replacement therapies (CRRT), and alternative methods of anticoagulation may be required. Our aim was to evaluate, in patients with a high risk of bleeding, the possibility of an acceptable filter life with non-anticoagulation CRRT and, in case of early filter failure, the efficacy and safety of bedside monitored regional anticoagulation with heparin and protamine.

METHODS

Fifty-nine patients underwent CRRT for acute renal failure (ARF) following cardiac surgery. Patients who fulfilled one of the following criteria were selected for non-anticoagulation CRRT: spontaneous bleeding, aPTT > 45 sec, thrombocytopenia and recent surgery (< 48 hr). Filter life < 24 hr without anticoagulation was the cut-off point for starting the regional anticoagulation CRRT. Heparin was infused pre-filter and protamine post-filter at an initial ratio of 1 mg protamine:100 IU heparin. The ratio was adjusted to achieve a patient aPTT < 45 sec and a circuit > 55 sec.

RESULTS

Twenty-two (37.3%) patients had been selected for non-anticoagulation. Of them, 12 patients continued to receive non-anticoagulation (filter life: 38.3 +/- 30.5 hr) while 10 switched to regional anticoagulation (filter life: 38.6 +/- 25 hr). During regional anticoagulation no statistical difference was found between baseline aPTT (36.7 +/- 6.4 sec) and patient aPTT (41.5 +/- 12.6 sec) while circuit aPTT (77.7 +/- 43.3 sec) was significantly higher than patient aPTT (p < 0.0001). The probabilities of the circuits remaining free from clotting after 24, 48 and 72 hr were: a) non-anticoagulation: 55.5%, 30.1% and 16.6%, b) regional anticoagulation: 76.2%, 39.6% and 19.8%. There was no rebound anticoagulation observed after regional anticoagulation CRRT ended.

CONCLUSIONS

Non-anticoagulation CRRT allowed an adequate filter life in most patients with a high risk of bleeding for prolonged aPTT and/or thrombocytopenia. Despite concerns regarding the need for careful monitoring, regional anticoagulation with heparin and protamine can be considered as a safe and valid alternative when non-anticoagulation is unsuitable because of early filter failure.

Interleukin-1beta induces apoptosis in GL15 glioblastoma-derived human cell line

Interleukin 1-beta (IL-1beta) induces apoptosis in a glioblastoma-derived human cell line, exhibiting a poorly differentiated astrocytic phenotype. The apoptotic effect was demonstrated by analyzing nuclear morphology, in situ DNA fragmentation, and by ELISA detection of cytoplasmatic nucleosomes. We correlated the degree of differentiation of GL15 cells with the apoptotic response: 1) 4',6-diamidino-2-phenylindole staining, combined with glial fibrillary acidic protein (GFAP) immunofluorescence, showed that the cells with apoptotic nuclei express low levels of GFAP; and 2) at 13 days of subculture, in a more differentiated state, GL15 cells did not respond with apoptosis to IL-1beta. In this cell line, nonrandom chromosome changes and the expression of SV40 early region have been previously shown. The involvement of p42/p44 mitogen-activated protein kinase (MAPK) pathway in the induction of apoptosis by IL-1beta was hypothesized. Previous studies have shown that SV40 small T antigen partially inhibits phosphatase 2A, leading to an enhancement of the steady-state activity of p42/p44 MAPK pathway. PD-098059, specific inhibitor of p42/p44 MAPK pathway, counteracts the apoptotic effect of IL-1beta, whereas SB-203580, specific inhibitor of p38 stress-activated protein kinase (SAPK) pathway, is ineffective. The imbalance between MAPK and SAPK pathways has been proposed as a key factor in determination of cell fate. Our results demonstrate that a further stimulation of p42/p44 MAPK pathway can constitute a death signal in tumor cells in which genomic damage and MAPK pathway control alterations occur.

Prevention of migraine during prodrome with naratriptan

OBJECTIVE

To determine the role of naratriptan in preventing migraine headache when administered during prodrome.

PROCEDURES

Baseline phase: patients recorded prodrome symptoms and time of onset, time when patient knew that headache was inevitable, time of onset and severity of headache. Treatment phase: patients given naratriptan 2.5 mg to take at the time they knew headache was inevitable. Patients recorded prodrome symptoms and time of onset, time they knew headache was inevitable, time naratriptan administered, time of onset and severity of any headache. Patients treated three prodromes separated by at least 48 h.

FINDINGS

Twenty patients completed both phases. During baseline phase, 59 prodromes were reported and all were followed by headache. Severity of headache: 5% mild, 51% moderate, 44% severe. During treatment phase, 63 prodromes were reported. Of these, 38/63 (60%) were not followed by headache. Among headaches that occurred, the majority occurred within 2 h of naratriptan administration, suggesting that naratriptan is more effective in preventing headache if taken early in prodrome. Severity of 25 headaches: 44% mild, 24% moderate, 32% severe.

CONCLUSIONS

Naratriptan 2.5 mg appears to prevent migraine headache when given early in prodrome. If headache occurs, severity appears to be reduced.