High-dose glucocorticosteroids increase the procoagulant effects of OKT3

Kidney allograft infarction associated with transplant renal artery stenosis in a COVID-19 kidney transplant recipient

Kidney allograft infarction is rare, but an urgent condition that requires prompt intervention to avoid allograft loss. Renal artery thrombosis is the leading cause of infarction. Apart from traditional risk factors for thrombosis, emerging SARS-CoV-2 predisposes patients to thrombotic diseases both in arterial and venous vasculatures. We report a case of kidney transplant recipient with known transplant renal artery stenosis (TRAS) status post angioplasty with severe COVID-19, complicated by oliguric acute kidney injury requiring continuous renal replacement therapy (CRRT). She did not have a history of thromboembolic disease. The hospital course was complicated by new-onset atrial and ventricular fibrillation and cardiac arrest requiring multiple rounds of cardiopulmonary resuscitation. She had no signs of renal recovery, and an abdominal CT scan showed evidence of allograft infarcts. She underwent an allograft nephrectomy. Pathology revealed diffuse thrombotic microangiopathy involving glomeruli, arterioles, and arteries associated with diffuse cortical infarction with negative SARS-CoV-2 immunostain and in situ hybridization. This is the first case of kidney allograft infarct with a history of TRAS in a COVID-19 patient. Underlying TRAS and COVID-19-associated thrombosis in this patient are unique and likely play a key role in allograft infarction from arterial thrombosis. Recognizing risk factors and early therapy for allograft infarction may improve transplant outcomes.

Ten Years of Orthoclone OKT3 (Muromonab-CD3): A Review

Many important advances in transplantation have been made during the last decade. The introduction of Orthoclone OKT3 into clinical trials and its subsequent approval by the Food and Drug Administration in 1985 for use as an antirejection agent for renal transplantation were landmarks in the field of clinical transplantation of solid organs. In the decade since the approval of OKT3 for clinical use, much has been learned and written about OKT3. OKT3 now is considered a safe and effective agent for prophylaxis and first-line treatment of acute rejection of solid organ allografts. In this article, the development and use of OKT3 over the last 10 years, as well as the present status and future implications of immune therapy with OKT3, are reviewed.

Hyperdense large artery sign in meningitis: A marker of ominous thrombogenic potential of pneumococcus?

Hyperdensity in the middle cerebral artery (MCA) or posterior cerebral artery (PCA) on non-contrast head CT, suggests the presence of a thrombus inside these vessels, often referred to as the “MCA sign” or “PCA sign” respectively. These two signs are classically associated with strokes secondary to cardiovascular etiologies and are only infrequently reported with other types of stroke. Whereas stroke is a recognized complication of pneumococcal meningitis hyperdense large vessel sign (in this case a combination of MCA and PCA) has not been previously reported. We report a case of rapidly progressive pneumococcal meningitis that presented as acute stroke involving large vessels in the vicinity of the circle of Willis in a patient with a history of non-Hodgkin lymphoma (NHL) in remission for 6 years. This patient had received a week of high dose steroids before admission. Head CT scan on admission showed the presence of hyperdense MCA and PCA signs. The patient rapidly deteriorated and a follow-up head CT revealed diffuse brain edema and increased density in the basal cisterns without evidence of sub arachnoid hemorrhage. Tc99m exametazime brain flow scan showed no intracerebral blood flow both supra and infratentorially. Steptococcus pneumoniae, NHL cells and high-dose steroid use can upregulate tissue factor synthesis and may have led to a hypercoagulable state via activation of the extrinsic pathway in the large intracerbral arteries.

Vascular complication in live related renal transplant: An experience of 1945 cases

Introduction and Objective:

Among the surgical complications in renal transplantation, the vascular complications are probably most dreaded, dramatic, and likely to cause sudden loss of renal allograft. We present our experience and analysis of the outcome of such complications in a series of 1945 live related renal transplants.

Materials and Methods:

One thousand nine hundred and forty five consecutive live related renal transplants were evaluated retrospectively for vascular complications. Complications were recorded and analyzed for frequency, time of presentation, clinical presentation, and their management.

Results:

The age of patients ranged from 6 to 56 years (mean = 42). Vascular complications were found in 25 patients (1.29%). Most common among these was transplant renal artery stenosis found in 11 (0.58%), followed by transplant reznal artery thrombosis in 9 (0.46%), renal vein thrombosis in 3 (0.15%), and aneurysm formation at arterial anastmosis in 2 (0.10%) patient. The time of presentation also varied amongst complications. All cases of arterial thrombosis had sudden onset anuria with minimal or no abdominal discomfort, while venous thrombosis presented as severe oliguria associated with intense graft site pain and tenderness. Management of cases with vascular thrombosis was done by immediate surgical exploration. Two patients of renal artery stenosis were managed with angioplasty and stent placement.

Conclusions:

Major vascular complications are relatively uncommon after renal transplantation but still constitute an important cause of graft loss in early postoperative period. Aneurysm and vessel thrombosis usually require graft nephrectomy. Transplant renal artery stenosis is amenable to correction by endovascular techniques.

Diffuse cerebral intravascular coagulation and cerebral infarction in pneumococcal meningitis

BACKGROUND

There is a widely held belief that cerebral infarction after bacterial meningitis is always caused by vasculitis; however, evidence is weak. We hypothesized that diffuse cerebral intravascular coagulation is an additional explanation of cerebral infarction in patients with pneumococcal meningitis.

METHODS

Sixteen brains of adults who died from pneumococcal meningitis were investigated. Clinical data were collected, and brain sections were scored for signs of inflammation and activation of coagulation. Patients with and without cerebral infarction on autopsy were compared.

RESULTS

In total, 38% of patients had focal neurological deficits. Patients died at a median of 7 days (range, 0-32 days) after admission. On autopsy, the nine patients (56%) with cerebral infarctions more often had arterial thrombosis (p = 0.04) than patients without infarction. Patients with infarction tended to have more inflammatory infiltrations of brain parenchyma, microvascular proliferation, small vessel vasculitis/endarteritis obliterans, blood clotting/vessel clogging, and venous thrombosis. None of the patients had large vessel vasculitis. Five patients had cerebral infarctions without vasculitis or endarteritis obliterans. Although four patients with cerebral infarctions had small vessel vasculitis or endarteritis obliterans, areas of infarction could not be localized to the blood flow distribution of these vessels. Blood clotting/vessel clogging was seen in all four patients with vasculitis or endarteritis obliterans, but this was also observed in 10 patients without vasculitis or endarteritis obliterans. None of the patients developed disseminated intravascular coagulation.

CONCLUSIONS

Our results suggest that diffuse cerebral intravascular coagulation is an additional explanation of cerebral infarction complicating pneumococcal meningitis.

Immunomodulators: interleukins, interferons, and IV immunoglobulin

The outstanding progress in immunology and the development of new technologies have resulted in the introduction of new immunotherapies, the so-called “immunomodulators”, for autoimmune diseases, inflammatory disorders, allograft rejection, and cancer. These immunomodulators comprise recombinant cytokines and specific blocking or depleting antibodies. Many of these therapies achieve their effect by stimulating the release of cytokines. The term cytokines includes interleukins (IL-), chemokines, growth factors, interferons (IFN), colony stimulating factors (CSF), and tumor necrosis factors (TNF). These molecules are involved in inflammation, cell proliferation and apoptosis, tissue injury and repair.

These new therapeutic tools can be associated with side effects among which nephrotoxicity. The most common immunomodulators associated with nephrotoxicity are described in Table 1. The nephrotoxic side effects of immunomodulators can be roughly divided into (ischemic) tubular necrosis, thrombotic microangiopathy, serum sickness, and autoimmune disorders.

Effects of short-term glucocorticoids on hemostatic factors in healthy volunteers

OBJECTIVE

Increased circulating levels of hemostatic factors have been associated with arterial and venous thrombosis. Although in vitro evidence suggests that glucocorticoids may activate hemostasis and inhibit thrombolysis, no controlled in vivo studies have examined the effects of glucocorticoids on hemostatic factors. We hypothesized that a 5-day treatment course of dexamethasone would increase circulating levels of hemostatic and anti-fibrinolytic factors.

METHODS

We randomized 24 healthy men ages 19-39 to receive either dexamethasone 3 mg twice daily versus placebo for 5 days. Parameters examined before and after the intervention included: clotting factors VII, VIII, and XI, von Willebrand factor (vWF), D-dimer, PAI-1, soluble CD40-ligand (sCD40-ligand), and fibrinogen.

RESULTS

Dexamethasone tended to modestly increase clotting factors levels and fibrinogen without significantly affecting PAI-1, D-dimer or sCD40-ligand. Factor VII increased by a mean of 13% (p = 0.04 versus placebo), factor VIII by 27% (p = 0.0008), factor XI by 6% (p = 0.01), and fibrinogen by 13% (p = 0.05).

CONCLUSIONS

Glucocorticoids may increase the activity of clotting factors in vivo. This may contribute to the reported increased risk of thrombosis in patients with sustained exposure to glucocorticoids.

Efficacy of methylprednisolone pulse therapy in steroid-resistant nephrotic syndrome

Steroid-resistant nephrotic syndrome (SRNS) in children is intractable, and the optimal treatment regimen is not known. We investigated the efficacy of methylprednisolone pulse therapy (MPT) in SRNS patients. Using only MPT plus heparin, we have treated ten pediatric SRNS patients that were resistant to cyclophosphamide (CPM) or cyclosporin A (CsA) and predicted to have a very poor prognosis. Administration of 30 mg/kg per day methylprednisolone with heparin for 3 days was taken as one course, and this was given 14 times over 2 years. One patient discontinued MPT because of peritonitis. Of the remaining nine patients, complete remission was achieved by four patients, persistent mild proteinuria remained in three patients, and no effect was observed in two patients. All patients that had been diagnosed with minimal change (MC) pathology ( n=3) at the initial renal biopsy achieved complete remission. Observed adverse events were peritonitis in one patient and a transient decrease in pulse rate only during MPT in one patient. These results demonstrate that MPT with heparin can induce remission in children with SRNS, even when the patient is resistant to CPM and CsA.

Ten years of Orthoclone OKT3 (muromonab-CD3): a review

Many important advances in transplantation have been made during the last decade. The introduction of Orthoclone OKT3 into clinical trials and its subsequent approval by the Food and Drug Administration in 1985 for use as an antirejection agent for renal transplantation were landmarks in the field of clinical transplantation of solid organs. In the decade since the approval of OKT3 for clinical use, much has been learned and written about OKT3. OKT3 now is considered a safe and effective agent for prophylaxis and first-line treatment of acute rejection of solid organ allografts. In this article, the development and use of OKT3 over the last 10 years, as well as the present status and future implications of immune therapy with OKT3, are reviewed.

Muromonab CD3: a reappraisal of its pharmacology and use as prophylaxis of solid organ transplant rejection

The murine monoclonal antibody muromonab CD3 (OKT3) is directed against the CD3 antigen on peripheral human T cells and effectively blocks all T cell function. Prophylaxis with muromonab CD3 (5mg intravenously once daily for 10 to 14 days) as induction therapy together with corticosteroids, azathioprine and delayed cyclosporin (sequential therapy) optimises early graft function by delaying the potentially nephrotoxic and hepatotoxic effects of cyclosporin until graft function is established. Although clinical data are limited (by inconsistencies in trial design and trial size), prophylactic muromonab CD3-based sequential therapy is significantly more effective than standard triple therapy in the prophylaxis of allograft rejection in renal and hepatic, but not cardiac, transplant recipients. Benefits are particularly notable in patients with delayed graft function. No significant between-treatment differences in patient survival have been observed. The overall efficacy of muromonab CD3- and polyclonal-based prophylactic regimens appears to be similar, although results vary between investigators and confirmation is needed. An anti-interleukin-2 monoclonal antibody-based prophylactic regimen improved graft and patient survival compared with muromonab CD3-based prophylaxis in hepatic transplant recipients. Antimuromonab CD3 antibodies may develop; however, muromonab CD3 may be successfully reused in patients with low titres. Preliminary pharmacoeconomic data suggest that mean drug costs are greater with quadruple immunosuppressive regimens containing muromonab CD3, antithymocyte globulin (ATG) or antilymphocyte globulin (ALG) than with triple therapy. Drug costs with prophylactic muromonab CD3-based regimens were similar or greater than those with polyclonal-based protocols. The first doses of muromonab CD3 are associated with the 'cytokine-release syndrome'. More severe first-dose events include aseptic meningitis, intragraft thromboses, seizures and potentially fatal pulmonary oedema. The incidence and/or severity of cytomegalovirus infection with prophylactic muromonab CD3 based immunosuppression is similar to or greater than that with triple therapy and ATG- or ALG-based regimens. However, the risk of infection and also the observed increase in lymphoproliferative disorders appears to be related to the degree of immunosuppression rather than to the drug itself Thus, sequential muromonab CD3-based therapy is more effective than standard triple therapy (in renal and hepatic transplant recipients) and appears to be similar to that of polyclonal-based regimens in the prophylaxis of transplant rejection. Although the routine use of prophylactic muromonab CD3 in low-risk patients with primary graft function does not appear to be justified, prophylactic muromonab CD3-based therapy has a role in patients at high risk of rejection.

OKT3 prophylaxis in renal grafts with prolonged cold ischemia times: association with improvement in long-term survival

The data on patients participating in two randomized, prospective studies with similar immunosuppressive regimens were updated and combined to evaluate the long-term effects of OKT3 according to cold ischemia time (< or = or > 24 hr). Among 159 patients in the OKT3 and 153 in the cyclosporine A (CsA) group, 8 and 12 deaths occurred, respectively (P = NS). In patients with cold ischemia > 24 hours, OKT3 prophylaxis resulted in a lower mean number of rejection episodes per patient than did CsA prophylaxis within one year (mean +/- SEM: 0.87 +/- 0.11 vs. 1.35 +/- 0.14, respectively; P = 0.008) and within five years (1.07 +/- 0.12 vs. 1.49 +/- 0.15, respectively; P = 0.032). In contrast, rejection incidences in patients with cold ischemia < or = 24 hours was not significantly different in the two groups. In all study patients, there was a trend towards higher graft survival rates in the OKT3 group versus the CsA group (at 5 years, 73% vs. 66%, respectively; P = 0.182). Among recipients of kidneys with cold ischemia times > 24 hours, OKT3 patients had significantly higher graft survival than CsA patients at two years (84% vs. 64%, respectively) and at five years (71% vs. 56%, respectively; P = 0.045). Significant differences were not observed in recipients of kidneys with cold ischemia times < or = 24 hours. In conclusion, patients receiving renal grafts with long cold ischemia times strongly benefit from OKT3 prophylaxis.