A retrospective multi-center experience of renal transplants from India during COVID-19 pandemic.

INTRODUCTION: Coronavirus disease 2019 (COVID-19) pandemic led to a sudden drop in renal transplant numbers across India in the initial months of 2020. Although the transplant numbers increased with easing of lockdown, the outcome of these transplants remains unknown. METHODS: This was a retrospective, observational, multi-center study done across eight different transplant centers in India. All the transplants done from January 30, 2020 to December 31, 2020 were included. The primary outcomes studied were patient and death censored graft survival as well as incidence of COVID-19 infection and its outcomes. RESULTS: During the study period a total of 297 kidney transplants were done. After a median follow up of 265 days the patient and death censored graft survival was 95.3% and 97.6%, respectively. Forty-one patients (13.8%) developed COVID-19 post-transplant. Majority (58.5%) were asymptomatic to mildly symptomatic and the case fatality ratio was 14.6%. On multivariable logistic regression analysis older age was associated with higher likelihood of COVID-19 infection (odds ratio 1.038; CI 1.002-1.077). CONCLUSIONS: Patient and graft outcome of kidney transplants done during the COVID-19 pandemic in India was acceptable. The incidence of COVID-19 was 13.8% with a high case fatality ratio.

Adenosine modulates light responses of rat retinal ganglion cell photoreceptors througha cAMP-mediated pathway.

Adenosine is an established neuromodulator in the mammalian retina, with A1 adenosine receptors being especially prevalent in the innermost ganglion cell layer. Activation of A1 receptors causes inhibition of adenylate cyclase, decreases in intracellular cyclic AMP (cAMP) levels and inhibition of protein kinase A (PKA). In this work, our aim was to characterize the effects of adenosine on the light responses of intrinsically photosensitive retinal ganglion cells (ipRGCs) and to determine whether these photoreceptors are subject to neuromodulation through intracellular cAMP-related signalling pathways. Using multielectrode array recordings from postnatal and adult rat retinas, we demonstrated that adenosine significantly shortened the duration of ipRGC photoresponses and reduced the number of light-evoked spikes fired by these neurons. The effects were A1 adenosine receptor-mediated, and the expression of this receptor on melanopsin-containing ipRGCs was confirmed by calcium imaging experiments on isolated cells in purified cultures. While inhibition of the cAMP/PKA pathway by adenosine shortened ipRGC light responses, stimulation of this pathway with compounds such as forskolin had the opposite effect and lengthened the duration of ipRGC spiking. Our findings reveal that the modification of ipRGC photoresponses through a cAMP/PKA pathway is a general feature of rat ganglion cell photoreceptors, and this pathway can be inhibited through activation of A1 receptors by adenosine. As adenosine levels in the retina rise at night, adenosinergic modulation of ipRGCs may serve as an internal regulatory mechanism to limit transmission of nocturnal photic signals by ipRGCs to the brain. Targeting retinal A1 adenosine receptors for ipRGC inhibition represents a potential therapeutic target for sleep disorders and migraine-associated photophobia.

ABO-Incompatible Kidney Transplantation in India: A Single-Center Experience of First Hundred Cases.

Aim: ABO-incompatible (ABOi) kidney transplantation overcomes immunological barrier of blood group incompatibility. There have been very few published experiences of ABOi kidney transplantation from India. We present our single-center experience of the first hundred ABOi kidney transplants. Material and Methods: This is a single-center retrospective study of consecutive first hundred ABOi kidney transplant with at least 6 months of follow-up. Results: During the study period (2011-2020), a total of 121 ABOi kidney transplants were performed. Of these, first hundred patients were analyzed. Median follow-up duration was 33 (10-101) months. Mean recipient and donor age were 41.5 ± 13 and 47.68 ± 11.25 years, respectively. Mean HLA mismatch was 4 ± 1.5. Median baseline anti-blood group antibody titer was 128 (2-1024). Most common recipient blood group was O. Patient and death censored graft survival was 93% and 94%, respectively, at median follow-up of 33 months. Biopsy-proven acute rejection (BPAR) rate was 17% with acute antibody-mediated rejection being 3%. Rate of infection was 37%, most common being urinary tract infection. Conclusion: ABOi kidney transplant patients had acceptable patient and graft survival as well as BPAR rates. With current preconditioning protocol, infection rate was high.

COVID-19 in Renal Transplant Recipients - A Single Center Experience from India.

Introduction: The information on the clinical outcome of renal transplant recipients getting COVID-19 infection is sparse. The aim of this study is to report a single-center experience of renal transplant recipients with COVID-19 from India. Methods: This was a retrospective study of 23 consecutive renal transplant recipients with COVID-19 infection presenting to our center from May 2020 to August 2020. Clinical parameters, laboratory values, imaging characteristics, and outcome of the patients were collected and analyzed. Results: Median follow-up duration was 36 (range: 10-110) days. Median age of patients was 54 (23-70) years, and 87% were male. Median duration since transplant was 69 (range: 15-132) months. The most common presenting feature was fever (82.6%), followed by breathlessness (43.5%) and cough (30.4%). Hospitalization rate was 52.2%, while 34.8% required ICU care. Severe to critical disease was seen in 39.1% of patients, and 17.4% required mechanical ventilation. Patients with severe disease had a higher incidence of lymphopenia (P = 0.005) when compared to the ones with mild to moderate disease. Acute kidney injury was seen in 39.1% of patients, and 13% required dialysis. Mortality rate was 13% overall, and 25% in those hospitalized. Conclusion: Renal transplant recipients with COVID-19 have a poor outcome. Although not all of them need hospitalization, they should be monitored closely. Immunosuppression minimization is an important part of the treatment strategy.

Grafalon® vs. Thymoglobulin® as an Induction Agent in Renal Transplantation - A Retrospective Study.

INTRODUCTION: Antihuman thymocyte immunoglobulin, used as an induction agent in renal transplantation, is of two types - thymoglobulin and grafalon (formerly ATG-Fresenius). In this study, we compared outcomes with these two agents. METHODS: This was a single-center retrospective study of patients transplanted from January 2017 to October 2019, who received either grafalon or thymoglobulin induction. Grafalon or thymoglobulin was given at 6 and 3 mg/kg, respectively, followed by standard triple immunosuppression of tacrolimus, MMF, and prednisolone. RESULTS: Median follow up was 22 (3-36) months. Thymoglobulin was given to 255 patients, whereas 78 patients received grafalon. Baseline demographics were similar between the two groups although significantly more patients in the grafalon group received ABO incompatible transplant (15% vs. 4.3%; P = 0.002). Patient survival was similar between the two groups (99% in grafalon vs. 98.8% in thymoglobulin; P = 1.0). Death censored graft survival was also similar (99% in grafalon vs. 100% in thymoglobulin; P = 0.23). Biopsy proven acute rejection (BPAR) was significantly higher in the grafalon group (12.8% vs. 5.1%, P = 0.04). The significance persisted after multivariable regression analysis (P = 0.02). Other outcomes such as infection rate and estimated glomerular filtration rate on last follow up were comparable between the two groups. CONCLUSIONS: Grafalon (6 mg/kg dose) when used as an induction agent was associated with significantly higher rate of BPARs as compared to thymoglobulin (3 mg/kg dose) although with comparable short-term patient and death censored graft survival, graft function, and infection rates.

Reduction of hepatitis C virus using lectin affinity plasmapheresis in dialysis patients.

BACKGROUND/AIMS: To test the safety and efficacy of the Aethlon Hemopurifier, a lectin affinity cartridge, in clearing hepatitis C virus (HCV) from the blood of HCV-positive end-stage renal disease patients undergoing dialysis. Viral RNA was measured using real-time quantitative reverse transcriptase polymerase chain reaction. RESULTS: HCV clearance from plasma or blood was measured using either direct capture on immobilized Galanthus nivalis agglutinin (GNA) or using miniature plasmapheresis cartridges containing immobilized GNA. HCV in plasma samples was rapidly cleared by direct affinity capture (t(1/2) = approx. 20 min) and HCV in human blood was cleared using the Hemopurifier (t(1/2) = 2-3 h). Institutional-review-board-sanctioned clinical safety studies were conducted at the Apollo and Fortis Hospitals in India. At Apollo, 4 patients were treated 3 times/week for 2 weeks. HCV captured on the Hemopurifier averaged 8.9 x 10(8) viral copies/cartridge (n = 5), representing approximately 30% of the initial viral body burden. At Fortis, 3 patients treated 3 times/week for 1 week completed the viral load studies. Two patients showed measurable viral load reduction, while the third showed both increases and decreases in viral load. After Hemopurifier treatment, average HCV viral load was reduced by 57%. Surprisingly, average viral load was also 82% lower 7 days after treatment. Control samples also showed a marked transient reduction in HCV viral load as previously reported. CONCLUSION: The Hemopurifier rapidly cleared HCV from blood treated in vitro. In patients, the combination of the Hemopurifier plus dialysis decreased HCV viral load by 57% in 1 week. Moreover, viral load reduction continued up to 7 days after treatment.

µ-Opioid Receptor Activation Directly Modulates Intrinsically Photosensitive Retinal Ganglion Cells.

Intrinsically photosensitive retinal ganglion cells (ipRGCs) encode light intensity and trigger reflexive responses to changes in environmental illumination. In addition to functioning as photoreceptors, ipRGCs are post-synaptic neurons in the inner retina, and there is increasing evidence that their output can be influenced by retinal neuromodulators. Here we show that opioids can modulate light-evoked ipRGC signaling, and we demonstrate that the M1, M2 and M3 types of ipRGCs are immunoreactive for µ-opioid receptors (MORs) in both mouse and rat. In the rat retina, application of the MOR-selective agonist DAMGO attenuated light-evoked firing ipRGCs in a dose-dependent manner (IC50 < 40 nM), and this effect was reversed or prevented by co-application of the MOR-selective antagonists CTOP or CTAP. Recordings from solitary ipRGCs, enzymatically dissociated from retinas obtained from melanopsin-driven fluorescent reporter mice, confirmed that DAMGO exerts its effect directly through MORs expressed by ipRGCs. Reduced ipRGC excitability occurred via modulation of voltage-gated potassium and calcium currents. These findings suggest a potential new role for endogenous opioids in the mammalian retina and identify a novel site of action-MORs on ipRGCs-through which opioids might exert effects on reflexive responses to environmental light.

Muscarinic acetylcholine receptor-mediated stimulation of retinal ganglion cell photoreceptors.

Melanopsin-dependent phototransduction in intrinsically photosensitive retinal ganglion cells (ipRGCs) involves a Gq-coupled phospholipase C (PLC) signaling cascade. Acetylcholine, released in the mammalian retina by starburst amacrine cells, can also activate Gq-PLC pathways through certain muscarinic acetylcholine receptors (mAChRs). Using multielectrode array recordings of rat retinas, we demonstrate that robust spiking responses can be evoked in neonatal and adult ipRGCs after bath application of the muscarinic agonist carbachol. The stimulatory action of carbachol on ipRGCs was a direct effect, as confirmed through calcium imaging experiments on isolated ipRGCs in purified cultures. Using flickering (6 Hz) yellow light stimuli at irradiances below the threshold for melanopsin activation, spiking responses could be elicited in ipRGCs that were suppressed by mAChR antagonism. Therefore, this work identified a novel melanopsin-independent pathway for stimulating sustained spiking in ganglion cell photoreceptors. This mAChR-mediated pathway could enhance ipRGC spiking responses in conditions known to evoke retinal acetylcholine release, such as those involving flickering or moving visual stimuli. Furthermore, this work identifies a pharmacological approach for light-independent ipRGC stimulation that could be targeted by mAChR agonists.