EXPERIMENTAL AND CLINICAL TRANSPLANTATION

Objectives: Improvements in early graft survival and long-term graft function have made kidney transplant a more cost-effective alternative to dialysis. We aimed to assess renal transplant outcomes over a 9-month follow-up of recipients in a cost-limited setting (a tertiary care center in India).

Materials and Methods: Included patients in this prospective observational study were those who underwent renal transplant from July 2016 to February 2017 (8 months) and followed for 9 months.

Results: Of 122 included patients, 20 (16.4%) were women and 102 (83.6%) were men (mean age 35.61± 10.64 y), with 92 (75.4%) from a lower socioeconomic status. Kidneys were from first-degree relatives for 52 patients (42.6%), from spousal donors for 34 (27.9%), from deceased donors for 24 (19.7%), and from second/third degree relative donors for 12 (9.8%). All patients underwent only complement-dependent cytotoxicity crossmatch due to financial constraints. Fifty patients (41%) had history of packed red blood cell transfusion. Induction was thymog-lobulin in 60 patients (49.2%), basiliximab in 8 (6.6%), and no induction in 54 (44.3%). Forty patients (30.1%) underwent biopsy for graft dysfunction, and 32 (26.2%) had graft rejection: 18 (14.8%) with antibody-mediated rejection, 5 (4.1%) with T-cell-mediated rejection, and 9 (7.4%) with both. Opportunistic infections were shown in 24.5% of patients, including primarily cytomegalovirus (10.7%), tuberculosis (5.7%), and aspergillosis (3.3%). Twenty-nine patients (24%) had new-onset diabetes posttransplant. At end of follow-up, 93 patients (76.2%) had normal graft function, 21 (17.2%) had chronic graft dysfunction, 3 (2.4%) had graft loss, and 5 (4.1%) died. History of blood transfusion (P = .001) predicted the occurrence of antibody-mediated rejection, and induction used showed trend toward prediction (P = .083).

Conclusions: With high rejection rates, it would be prudent to include proper immunologic testing, even in cost-limited settings, pretransplant. The high infection and death rates are also concerning.

Key words : End-stage renal disease, Graft loss, Socioeconomic status

End-stage renal disease is quite common in develo-ping and developed countries, with significant morbidity and mortality. Renal transplant remains the treatment of choice for most patients, as it improves the patient’s quality of life and survival compared with dialysis.¹ Since the advent of renal transplant in 1954, patient and graft survival rates have improved significantly because of advances in surgical techniques, immunologic work-up, and immunosuppression. Because of different allocation policies, cultural differences influencing preferences for living versus deceased donations, and government-funded health care in some countries, it is possible that posttransplant outcomes remain vastly different in different countries.²

The living kidney transplant program in India has evolved in the past 45 years and is currently the second largest program in number after the United States.³ The prevalence of end-stage renal disease requiring transplant in India is estimated to be between 151 and 232 per million population.⁴ If an average of these figures is taken, it is estimated that almost 220 000 people require kidney transplant procedures in India. About 7500 kidney transplant procedures have been performed at 250 kidney transplant centers in India until now. Of these, 90% come from living donors and 10% from deceased donors. However, data are not as accurate as would be desirable due to the absence of a national transplant registry.³ In this study, our aim was to assess the outcomes of renal transplant, various causes of graft dysfunction, incidence of antibody-mediated rejection (ABMR) and factors predicting it, and opportunistic infections in a 9-month follow-up of renal transplant recipients in a cost-limited setting.

Materials and Methods

This prospective observational study was conducted at the Post Graduate Institute of Medical Education and Research in Chandigarh, India, from July 2016 to December 2017. During the 8-month recruitment period, all adult patients (age > 18 y) who underwent renal transplant were included; all included patients were actively followed for 9 months. Informed consent was obtained from each patient. The research was in compliance with the Declaration of Helsinki and approved by the local ethical committee.

Patient characteristics noted included age, sex, and socioeconomic status (according to modified Kuppuswamy scale), clinical history and their basic disease, type of donor, HLA matches, immunosup-pression strategy, and laboratory results, including hemogram blood tests, renal function tests, urine examinations, and 24-hour urinary protein. Donor-specific antibodies (DSAs) before and after therapy were recorded in available patients. Histopathologic and immunofluorescence/immunohistochemistry findings of renal biopsies of patients who underwent biopsy during follow-up were noted.

After transplant, all patients were treated with triple immunosuppression (tacrolimus + mycopheno-late mofetil + steroids). Daily urine output, serum creatinine levels, and alternate day serum tacrolimus levels were monitored. We kept day 10 as the cutoff for normalization of serum creatinine (≤ 1.2 mg/dL) irrespective of type of donor. Patients were initially followed weekly during month 1 posttransplant, then every 2 weeks during month 2, monthly during month 3 and later, and every 3 months at 9 months. Tacrolimus dose was modified according to tacrolimus levels. Patients underwent renal biopsy once they exhibited graft dysfunction in the form of elevated serum creatinine levels (> 1.2 mg/dL or elevation of > 25% from baseline). Included investigations were hemogram blood tests, renal function tests, complete urine examination, and 24-hour urinary protein at end of 1, 2, 3, 6, and 9 months.

Statistical analyses
All relevant data was recorded in Excel work-sheets.Statistical analyses were performed with SPSS software (SPSS: An IBM Company, version 22.0, IBM Corporation, Armonk, NY, USA). Continuous variables are presented as means and standard deviation, and categorical variables are presented as frequencies and percentages. Differences between groups were estimated by t tests for unpaired conti-nuous variables and chi-square tests/Fisher exact tests for categorical variables. Univariate and multivariate regression analyses were applied to find factors that predictedABMR (adjusted odds ratio). P < .05 was considered significant.

Of 122 included patients, 20 (16.4%) were women and 102 (83.6%) were men. Mean age was 35.61 ± 10.64 years. Most patients (n = 92; 75.4%) belonged to a lower socioeconomic status. Basic disease was unknown in 60 patients (49.2%); relative frequencies of basic diseases are shown in Table 1. Regarding type of donor, a first-degree related donor was the most common (n = 52; 42.6%), followed by spousal donor (n = 34; 27.9%), deceased donor (n = 24; 19.7%), and second/third-degree related donor (n = 12; 9.8%).

All patients underwent complement-dependent cytotoxicity (CDC) crossmatching; patients with prior renal transplant underwent additional flow crossmatching and tests for panel reactive antibodies. Forty-nine patients (40.2%) had history of blood transfusion (> 2 units in the last 2 years before transplant). Sixty patients (49.2%) received antithy-mocyte globulin, 8 (6.5%) received basiliximab, and 54 (44.3%) received no induction therapy. Among patients who did not receive induction therapy, 2 had spousal donors; reason for not receiving induction was financial issues.

At the time of transplant, 3 patients (2.4%) were positive for hepatitis B surface antigen and received treatment with entecavir, and 10 patients (8.1%) were hepatitis C virus positive and were treated with direct-acting antiviral agents. These patients achieved sustained virologic responses at the end of treatment before transplant. Baseline parameters of patients are shown in Table 2.

Of 121 patients who completed follow-up, 1 patient died immediately after transplant due to surgical complications. Forty patients (30.1%) under-went renal biopsy due to graft dysfunction, and 32 patients (26.2%) showed rejection, including 27 (22.3%) with acute ABMR (24 patients [88.8%] had rejection within 1 month posttransplant and 3 [11.2%] had rejection from 1-3 months posttransplant; no patients had rejection episodes after 3 months). C4d was negative in 19 patients (70.4%), and C4d staining on biopsy tissue was done with immunohis-tochemistry rather than with immunofluorescence. Of 27 patients with ABMR, 21 (77.8%) had history of blood transfusion. Various causes of graft dys-function and their relative frequencies are shown in Figure 1. All patients with ABMR received only methylprednisolone, and none received plasma-pheresis or rituximab due to financial constraints.

Conversion from tacrolimus to cyclosporine occurred in 15 patients (12.4%) due to poor glycemic control (n = 6; 4.9%) and failure to achieve therapeutic levels (n = 9; 7.5%). All patients received cotrimoxazole prophylaxis for 6 months, and 67 patients (55.4%) received valganciclovir prophylaxis for 3 months. Incidence of new-onset diabetes posttransplant was 24%, 36 patients (29.7%) had diarrhea, and 26 patients (21.5%) had mycophenolate mofetil intolerance. Incidences of various viral, fungal, and tubercular infections posttransplant are shown in Table 3.

At the end of the 9-month follow-up, 93 patients (76.2%) had normal graft function (serum creatinine ≤ 1.2 mg/dL), 21 patients (17.2%) had chronic graft dysfunction (serum creatinine > 1.2 mg/dL for more than 3 mo), and 3 patients had graft loss (became dialysis dependent). Graft loss was due to ABMR in 2 patients who did not respond to therapy and recurrence of basic disease (C3 glomerulonephritis) in 1 patient. Five patients (4.1%) died, 4 due to infection (2 fungal, 1 disseminated tuberculosis, 1 bacterial pyelonephritis) and 1 due to surgical complications (Table 4).

Univariate regression analyses showed that history of blood transfusion and 24-hour urine protein results were significant indicators of rejection, with type of induction displaying a trend toward predicting ABMR. Multivariate regression analyses showed that history of blood transfusion and 24-hour urine protein remained statistically significant indicators.

Our prospective observational study of patients in a cost-limited setting showed high rejection rates, high rates of opportunistic infections, which tended to occur early following transplant, and overall poor graft survival due to limited resources.

Difficulty securing financing, compounded by the lack of a government policy for treatment of emerging chronic diseases, has been a major hurdle for the development of renal replacement therapy facilities in India. Kidney transplant has been recognized as the most viable form of long-term renal replacement therapy in India. Most kidney transplants in India are from living donors.⁵ In the present study, patients undergoing renal transplant were predominantly younger, with mean age of 35.61± 10.64 years, had a low socioeconomic status, and were males. Male patients were also more likely to have kidney transplant, as depicted by the high male-to-female ratio of 5:1. This could be attributed to the sociocultural peculiarities of Indian popu-lations, where male sex has preferred status.

Puttarajappa and associates⁶ reported an acute ABMR rate of 5% to 7% for kidney transplant recipients; ABMR was responsible for 20% to 48% of acute rejection episodes among their population of presensitized crossmatch-positive patients. In patients with high levels of DSAs (ie, sufficient to cause strongly positive crossmatch), the incidence of ABMR in the first month after transplant may be as high as 40%, whereas the incidence in patients with a negative crossmatch and DSA, shown by solid-phase assay, was less than 10%.⁷ Various guidelines recommend per-forming CDC crossmatching, flow crossmatching, and DSA testing in all renal transplant recipients before proceeding to renal transplant; however, in resource-constrained countries, only CDC may be sufficient. When we consider our current evidence, flow crossmatching and DSA should be performed in patients with history of sensitization. In our study, we performed only CDC crossmatching, irrespective of sensitization history, due to financial constraints and nonavailability of other immunologic tests at our center. With the higher rejection rates and poor graft survival due to inadequate immunologic work-up shown here, advanced immunologic work-up should be conducted, even in resource-poor settings.

C4d can be detected in biopsy specimens by 2 methods,8 either by immunofluorescence or by immunohistochemistry on paraffin-embedded tissue with a polyvalent antibody. C4d negativity in our study was 70.4%, despite the significant glomerular inflammation and peritubular capillary dilatation shown in biopsy tissue. These results are similar to other studies, including Loupy and associates9 and Sis and associates,¹⁰ who reported 60% negativity. According to these studies, C4d staining was inconsistent and not a sensitive indicator of parenchymal disease in the first year after transplant. Additional factors for higher C4d negativity are use of immunohistochemistry versus immunofluorescence, which is less sensitive and has increased intra- and interobserver variabilities.

At the end of follow-up, normal graft function was seen in 76.2% of patients, 17.2% of patients had chronic graft dysfunction, 2.4% of patients had graft loss, and 4.1% of patients (5/122) died. This lower graft survival was due to high rejection rate with inadequate treatment of rejection episodes due to financial constraints. Infections are a common cause of morbidity and mortality after transplant, and infections ranked second as cause of death in patients with allograft function. In our center, 24.5% of patients (30/122) had opportunistic infections during follow-up, with 10.7% having cytomegalovirus infections and 5.7% having tuberculosis. Although previous studies¹¹ have shown that opportunistic infections like aspergillosis and nocardiosis are common 6 months after renal transplant, our study found that these infections occurred earlier, perhaps related to the presence of predisposing comorbid conditions or low socioeconomic status and poor hygiene. Compared with previous results,12 the incidence of new-onset diabetes following renal transplant in our study was almost similar at 24%.

A history of blood transfusion was seen in 77.8% of patients with ABMR compared with only 29.8% in those without ABMR (P = .001). Incidence of ABMR was also higher in those who had a first-degree-related donor compared with those with donations from spouses (15/52, [28.8%] vs 5/34 [14.7%]), a result also observed previously.¹³ On univariate regression analyses, a history of blood transfusion and 24-hour urine protein results were statistically significant (both with P = .001); type of induction used also trended (P = .083) toward predicting ABMR. On multivariate regression analyses, a history of blood transfusion and 24-hour urine protein re-mained statistically significant.

Limitations and conclusions
This was a single-center observational study, with a small sample size and relatively short follow-up duration. Donor-specific antibody results were not available in all patients for diagnosis of ABMR. However, with the high rejection rates shown here, it would be prudent to include proper immunologic testing, even in cost-limited settings, prior to transplant. Similarly, the high infection and death rates are also a cause for concern.

Volume: 17 Issue: 1 January 2019 - Supplement - 1

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