Willingness to pay for kidney transplantation among chronic kidney disease patients in Ghana

BACKGROUND

Kidney transplantation is the preferred treatment for patients with end stage renal disease. However, it is largely unavailable in many sub-Sahara African countries including Ghana. In Ghana, treatment for end stage renal disease including transplantation, is usually financed out-of-pocket. As efforts continue to be made to expand the kidney transplantation programme in Ghana, it remains unclear whether patients with Chronic Kidney Disease (CKD) would be willing to pay for a kidney transplant.

AIM

The aim of the study was to assess CKD patients' willingness to pay for kidney transplantation as a treatment option for end stage renal disease in Ghana.

METHODS

A facility based cross-sectional study conducted at the Renal Outpatient clinic and Dialysis Unit of Korle-Bu Teaching Hospital among 342 CKD patients 18 years and above including those receiving haemodialysis. A consecutive sampling approach was used to recruit patients. Structured questionnaires were administered to obtain information on demographic, socio-economic, knowledge about transplant, perception of transplantation and willingness to pay for transplant. In addition, the INSPIRIT questionnaire was used to assess patients' level of religiosity and spirituality. Contingent valuation method (CVM) method was used to assess willingness to pay (WTP) for kidney transplantation. Logistic regression model was used to determine the significant predictors of WTP.

RESULTS

The average age of respondents was 50.2 ± 17.1 years with most (56.7% (194/342) being male. Overall, 90 out of the 342 study participants (26.3%, 95%CI: 21.7-31.3%) were willing to pay for a kidney transplant at the current going price (≥ $ 17,550) or more. The median amount participants were willing to pay below the current price was $986 (IQR: $197 -$1972). Among those willing to accept (67.3%, 230/342), 29.1% (67/230) were willing to pay for kidney transplant at the prevailing price. Wealth quintile, social support in terms of number of family friends one could talk to about personal issues and number of family members one can call on for help were the only factors identified to be significantly predictive of willingness to pay (p-value < 0.05).

CONCLUSION

The overall willingness to pay for kidney transplant is low among chronic kidney disease patients attending Korle-Bu Teaching Hospital. Patients with higher socio-economic status and those with more family members one can call on for help were more likely to pay for kidney transplantation. The study's findings give policy makers an understanding of CKD patients circumstances regarding affordability of the medical management of CKD including kidney transplantation. This can help develop pricing models to attain an ideal poise between a cost effective but sustainable kidney transplant programme and improve patient access to this ultimate treatment option.

Predictors and outcome of systemic lupus erythematosus (SLE) admission rates in a large teaching hospital in sub-Saharan Africa

Although it was previously believed that systemic lupus erythematosus was uncommon among Africans, it has become increasingly apparent that the incidence is higher, and socioeconomic challenges such as physician shortages, poor medical facility access, and poor health literacy may worsen prognosis. This retrospective study examines characteristics and outcomes of hospitalized systemic lupus erythematosus patients over a two-year period and serves as a baseline for comparison for future studies to examine the outcomes with the provision of more dedicated care. There were 51 patient admissions over a two-year period, with a mean duration from start of illness to admission of approximately two years. Duration of admission ranged from one to 140 days with a mean period of 26.12 days (SD ± 26.6). There were 22 deaths (43.1% of admissions), which were mainly due to infections and renal complications. Factors associated with risk of death in regression analysis were: infections, fever, disease flare, musculoskeletal involvement, amenorrhea, depression, a clinical finding of hepatomegaly, and chest infection. Understanding the effect and outcome of systemic lupus erythematosus across different countries can elucidate the role of genetic, environmental, and other causative factors in the progression of the disease.

Causes of Death in Hospitalized HIV Patients in the Early Anti-Retroviral Therapy Era

OBJECTIVE

To establish the cause(s) of death among persons with HIV and AIDS admitted to the Fevers Unit of the Korle-Bu Teaching Hospital (KBTH) in 2007 and to determine whether they were AIDS-related in the era of availability of HAART.

METHOD

Retrospective chart review of all deaths that occurred in the year 2007 among inpatients with HIV infection. Cause of Death (COD) was established with post mortem diagnosis, where not available ICD-10 was reviewed independently by two physicians experienced in HIV medicine and a consensus reached as to the most likely COD.

RESULTS

In the year under review, 215 (97%) of the 221 adult deaths studied were caused by AIDS and HIV-associated illnesses. Of these, 123 (55.7%) were due to an AIDS-defining illness as described in CDC Category 3 or WHO stage 4. Infections accounted for most of the deaths 158 (71.5%), many of them opportunistic 82 (51.8%). Tuberculosis was the commonest COD. Clinical diagnosis of TB was accurate in 54% of deaths, but was not validated by autopsy in 36% of deaths. There were few deaths (14.5%) in patients on HAART.

CONCLUSION

In a developing country like Ghana where HAART was still not fully accessible, AIDS-related events remained the major causes of death in persons living with HIV. Total scale-up of the ART programme with continuous availability of antiretrovirals is therefore imperative to reduce deaths from AIDS and HIV associated illnesses. There is need for interventions for early diagnosis as well as reduction in late presentation and also better diagnostic tools for tuberculosis.

Solution structure of the catalytic domain of human collagenase-3 (MMP-13) complexed to a potent non-peptidic sulfonamide inhibitor: binding comparison with stromelysin-1 and collagenase-1

The full three-dimensional structure of the catalytic domain of human collagenase-3 (MMP-13) complexed to a potent, sulfonamide hydroxamic acid inhibitor (CGS 27023) has been determined by NMR spectroscopy. The results reveal a core domain for the protein consisting of three alpha-helices and five beta-sheet strands with an overall tertiary fold similar to the catalytic domains of other matrix metalloproteinase family members. The S1' pocket, which is the major site of hydrophobic binding interaction, was found to be a wide cleft spanning the length of the protein and presenting facile opportunity for inhibitor extension deep into the pocket. Comparison with the reported X-ray structure of collagenase-3 showed evidence of flexibility for the loop region flanking the S1' pocket in both NMR and X-ray data. This flexibility was corroborated by NMR dynamics studies. Inhibitor binding placed the methoxy phenyl ring in the S1' pocket with the remainder of the molecule primarily solvent-exposed. The binding mode for this inhibitor was found to be similar with respect to stromelysin-1 and collagenase-1; however, subtle comparative differences in the interactions between inhibitor and enzyme were observed for the three MMPs that were consistent with their respective binding potencies.

Design and synthesis of thiol containing inhibitors of matrix metalloproteinases

A series of thiol containing derivatives was prepared. Several of these compounds were found to inhibit matrix metalloproteinases 1, 3, and 9 with selectivity towards 3 and 9. Compounds 15, 20, and 22 were administered to rats orally at 75 mumol/kg. Drug levels of compounds 20 and 22 in the plasma were found to exceed the IC50 values for MMP 3 and 9 four hours after administration.

Inhibition of interleukin-1alpha-induced cartilage oligomeric matrix protein degradation in bovine articular cartilage by matrix metalloproteinase inhibitors: potential role for matrix metalloproteinases in the generation of cartilage oligomeric matrix protein fragments in arthritic synovial fluid

OBJECTIVE

To determine whether matrix metalloproteinases (MMPs) degrade cartilage oligomeric matrix protein (COMP) to produce fragments similar to those found in synovial fluid (SF) from patients with arthritis.

METHODS

COMP fragments were generated in vitro by treating (a) bovine articular cartilage with interleukin-1alpha (IL-1alpha), (b) purified bovine COMP with MMPs, and (c) articular cartilage with MMPs. The fragments generated in each case were analyzed by Western blot, using an antibody to the C-terminal heptadecapeptide of COMP.

RESULTS

IL-1alpha stimulation of cartilage resulted in a fragmentation of COMP, which was inhibited by MMP inhibitors CGS 27023A and BB-94. Isolated, recombinant MMPs rapidly degraded purified COMP, as well as COMP residing in cartilage. Several COMP fragments produced in vitro had similar electrophoretic mobility to those in SF of patients with arthritis.

CONCLUSION

MMPs may contribute to the COMP fragments found in vivo. Quantitation of MMP-specific fragments may be useful in the evaluation of MMP inhibitors in patients with arthritis.

Solution structure of the catalytic domain of human stromelysin-1 complexed to a potent, nonpeptidic inhibitor

The full three-dimensional structure of the catalytic domain of human stromelysin-1 (SCD) complexed to a novel and potent, nonpeptidic inhibitor has been determined by nuclear magnetic resonance spectroscopy (NMR). To accurately mimic assay conditions, the structure was obtained in Tris buffer at pH 6.8 and without the presence of organic solvent. The results showed that the major site of enzyme-inhibitor interaction occurs in the S1' pocket whereas portions of the inhibitor that occupy the shallow S2' and S1 pockets remained primarily solvent exposed. Because this relatively small inhibitor could not deeply penetrate stromelysin's long narrow hydrophobic S1' pocket, the enzyme was found to adopt a dramatic fold in the loop region spanning residues 221-231, allowing occupation of the solvent-accessible S1' channel by the enzyme itself. This remarkable conformational fold at the enzyme binding site resulted in constriction of the S1' loop region about the inhibitor. Examination of the tertiary structure of the stromelysin-inhibitor complex revealed few hydrogen-bonding or hydrophobic interactions between the inhibitor and enzyme that can contribute to overall binding energy; hence the resultant compact structure may in part account for the relatively high potency exhibited by this inhibitor.

Discovery of CGS 27023A, a non-peptidic, potent, and orally active stromelysin inhibitor that blocks cartilage degradation in rabbits

Structure-activity relationships of a lead hydroxamic acid inhibitor of recombinant human stromelysin were systematically defined by taking advantage of a concise synthesis that allowed diverse functionality to be explored at each position in a template. An ex vivo rat model and an in vivo rabbit model of stromelysin-induced cartilage degradation were used to further optimize these analogs for oral activity and duration of action. The culmination of these modifications resulted in CGS 27023A, a potent, orally active stromelysin inhibitor that blocks the erosion of cartilage matrix.

Bioactive conformation of stromelysin inhibitors determined by transferred nuclear Overhauser effects

The transferred nuclear Overhauser effect has been used to determine the biologically active conformations of two stromelysin inhibitors. Both inhibitors used in this study were hydroxamic acids generated via chemical synthesis. These structures, representing the conformation of each inhibitor bound to stromelysin, superimposed with excellent agreement. The study also provided information on the shape and orientation of the S2' and S1' pockets of the enzyme relative to thermolysin. Comparisons were made between stromelysin and thermolysin inhibitors to critically examine thermolysin as a template for stromelysin-inhibitor design. The enzyme-bound conformations of these stromelysin inhibitors were determined for use as a template in conformationally restricted drug design.

HIV-1 transactivator protein Tat induces proliferation and TGF beta expression in human articular chondrocytes

The human immunodeficiency virus-1 (HIV-1) protein Tat binds to cell surface antigens and can regulate cellular responses. Tat has similar immunosuppressive effects as transforming growth factor-beta (TGF beta) and both inhibit lymphocyte proliferation. TGF beta is expressed by primary human articular chondrocytes and is their most potent growth factor. The present study analyzed the interactions of TGF beta and HIV Tat in the regulation of human articular chondrocytes. Synthetic or recombinant full-length Tat (1-86) induced chondrocyte proliferation and this was of similar magnitude as the response to TGF beta. Tat peptides that did not contain the RGD motif had similar chondrocyte stimulatory activity as full-length Tat. Among a series of Tat peptides, peptide 38-62 which contains the basic domain was the only one active, suggesting that this region is responsible for the effects on chondrocyte proliferation. Full-length Tat and peptide 38-62 synergized with TGF beta and induced proliferative responses that were greater than those obtained with any combination of the known chondrocyte growth factors. Further characterization of the interactions between Tat and TGF beta showed that Tat increased synthesis and TGF beta activity and TGF beta 1 mRNA levels. The stimulatory effects of Tat and peptide 38-62 on chondrocyte proliferation were reduced by neutralizing antibodies to TGF beta and by TGF beta antisense oligonucleotides. These results identify a virally encoded protein and a synthetic peptide derived from it as novel and potent chondrocyte growth stimuli which act at least in part through the induction of TGF beta.

Interleukin-11, an inducible cytokine in human articular chondrocytes and synoviocytes, stimulates the production of the tissue inhibitor of metalloproteinases

This study on the regulation of interleukin (IL)-11 expression in human connective tissue cells shows that IL-11 expression is not restricted to cells of hematopoietic origin but can also be induced in articular chondrocytes and synoviocytes. IL-11 mRNA was induced in chondrocytes in response to transforming growth factor (TGF)-beta 1 and IL-1 beta. Stimulation with IL-6 or growth factors, such as basic fibroblast growth factor, leukemia inhibitory factor, and platelet-derived growth factor-AA, had only weak or no detectable effects. Activation of protein kinase C by phorbol esters and inhibition of protein synthesis by cyclohexamide increased IL-11 transcripts, whereas calcium ionophore A23817 or dibutyryl cyclic AMP had no effect. Immunoprecipitations revealed the synthesis of IL-11 protein in response to TGF-beta 1, IL-1 beta, as well as phorbol 12-myristate 13-acetate, and a synergistic action of TGF-beta 1 and IL-1 beta was observed. Similar findings on IL-11 expression were made in synoviocytes. Analysis of effects on cell function showed that IL-11 stimulated the production of the tissue inhibitor of metalloproteinases in chondrocytes and synoviocytes but did not affect chondrocyte proliferation or increase stromelysin activity. These results suggest that IL-11 does not contribute to connective tissue degradation but conversely induces protective effects in joint tissue.

A stromelysin assay for the assessment of metalloprotease inhibitors on human aggregated proteoglycan

Human proteoglycan was aggregated to an immobilized hyaluronan solid phase on a 96-well ELISA plate. This complex was then degraded by recombinant human stromelysin. The remaining proteoglycan fragments were detected using a monoclonal antibody probe directed against the chondroitin sulfate (CS) region of the core protein. Stromelysin degraded the aggregate in a time and dose dependent manner as reflected by the loss of the CS epitope. Assay sensitivity was 0.125 U/well with total loss of the CS epitope occurring at 4 U/well. o-phenanthroline (IC50 = 52 microM) and U24522 (IC50 = 9 microM) inhibited degradation, while phosphoramidon did not. Serine and cysteine protease inhibitors had no effect. A comparative analysis of this assay with a reference method, substance P assay, gave similar inhibitor profiles. The use of aggregated human proteoglycan (native conformation) as a substrate, may better reflect how stromelysin inhibitors behave in the presence of complex substrates such as cartilage matrix.

Thick filter neutrophil chemotaxis performed in the absence of albumin

Migration through a filter is a technique widely used for the study of cell chemotaxis. Since the original description of the technique by Boyden in 1962 (J. Exp. Med. 115, 453) using neutrophils and thick filters prepared from cellulose nitrate, albumin has been required in the incubation medium to support chemotaxis. However, the binding to albumin of compounds affecting chemotaxis can reduce their free concentration. We developed two procedures for studying neutrophil chemotaxis under reduced or albumin-free conditions. In one, cellulose nitrate filters were pretreated with albumin by a novel procedure and chemotaxis was carried out in albumin-free medium. As tested with the chemoattractant LTB4 and human neutrophils, the procedure resulted in full chemotaxis, measured by the number of cells crossing the filter, with an EC50 of 0.43 nM for LTB4. The LTB4-receptor antagonist LY 223982 inhibited the chemotactic action of LTB4 with a Ki of 62 nM in the albumin-pretreated filter system, thus showing 58 times greater potency than in medium containing 0.5% albumin. The second procedure makes use, for the first time, of a relatively new filter (Hydrophilic Durapore). This filter has the same dimensions and pore rating of the cellulose nitrate filter but did not require pretreatment with albumin to support chemotaxis in the albumin-free medium. LTB4 stimulated neutrophil chemotaxis across this filter with an EC50 of 0.29 nM. LY 223982 had a Ki of 11 nM, thus exhibiting a potency even greater than in the albumin-pretreated cellulose nitrate filter system. fMLP and C5a also stimulated chemotaxis in the absence of albumin. These results suggest that albumin is not obligatory for neutrophil chemotaxis through thick filters. The role of albumin in the chemotaxis assay using cellulose nitrate filters may be to counteract the adherence of cells or chemotactic agents to the filters.