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Tse KC, Li FK, Tang S, Chan TM, Lai KN. Peritoneal dialysis in patients with refractory ascites. Perit Dial Int 2001; 21:626-7. [PMID: 11783779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
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227
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Lui SL, Tang S, Li FK, Choy BY, Chan TM, Lo WK, Lai KN. Tuberculosis infection in Chinese patients undergoing continuous ambulatory peritoneal dialysis. Am J Kidney Dis 2001; 38:1055-60. [PMID: 11684559 DOI: 10.1053/ajkd.2001.28599] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A retrospective study of the prevalence and pattern of tuberculosis in patients undergoing continuous ambulatory peritoneal dialysis (CAPD) was performed. Thirty-eight cases of tuberculosis were diagnosed among 790 patients (18 men, 20 women; mean age, 58 +/- 12.6 years) between July 1994 and June 2000. The interval between the initiation of CAPD and onset of tuberculosis ranged from 1 to 168 months (median, 22 months). There were 18 cases of pulmonary tuberculosis, 14 cases of tuberculous peritonitis, 5 cases of tuberculous lymphadenitis, and 1 case of tuberculous synovitis. Patients with pulmonary tuberculosis usually presented with fever, constitutional symptoms, and pleural effusion or pulmonary infiltrates on chest radiograph. Abdominal pain and turbid dialysate were the main presenting symptoms in patients with tuberculous peritonitis. Diagnosis was established by positive culture in 20 patients, typical histological characteristics on a tissue biopsy specimen in 10 patients, and response to empirical antituberculous treatment in 8 patients. The duration of symptoms before the diagnosis of tuberculosis and initiation of antituberculous treatment ranged from 7 to 57 days (median, 30 days). Antituberculous treatment consisted of isoniazid, rifampicin, pyrazinamide, and ofloxacin for 9 to 15 months. Antituberculous treatment generally was well tolerated. Twenty-seven patients (71%) completed antituberculous treatment. No recurrence of tuberculosis was observed after a mean follow-up of 19.8 months. Eleven patients (29%) died while on antituberculous treatment; none of the deaths appeared to be directly caused by tuberculosis. We conclude that: (1) tuberculosis is prevalent among CAPD patients in our locality; (2) extrapulmonary tuberculosis, particularly tuberculous peritonitis, is common; and (3) a high index of suspicion for tuberculosis among CAPD patients is warranted to ensure early diagnosis and prompt initiation of treatment.
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MESH Headings
- Aged
- Antitubercular Agents/therapeutic use
- Female
- Hong Kong
- Humans
- Kidney Failure, Chronic/complications
- Kidney Failure, Chronic/therapy
- Male
- Middle Aged
- Mycobacterium tuberculosis/drug effects
- Mycobacterium tuberculosis/isolation & purification
- Peritoneal Dialysis, Continuous Ambulatory
- Peritonitis, Tuberculous/complications
- Peritonitis, Tuberculous/drug therapy
- Peritonitis, Tuberculous/mortality
- Survival Rate
- Treatment Outcome
- Tuberculosis/complications
- Tuberculosis/drug therapy
- Tuberculosis/mortality
- Tuberculosis, Lymph Node/complications
- Tuberculosis, Lymph Node/drug therapy
- Tuberculosis, Lymph Node/mortality
- Tuberculosis, Pulmonary/complications
- Tuberculosis, Pulmonary/drug therapy
- Tuberculosis, Pulmonary/mortality
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Tang S, Cheng CC, Tse KC, Li FK, Choy BY, Chan TM, Lai KN. CAPD-associated peritonitis caused by Alcaligenes xylosoxidans sp. xylosoxidans. Am J Nephrol 2001; 21:502-6. [PMID: 11799270 DOI: 10.1159/000046657] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Alcaligenes xylosoxidans is an uncommon cause of peritonitis in patients on maintenance continuous ambulatory peritoneal dialysis (CAPD). Peritonitis caused by A. xylosoxidans usually carries a poor prognosis because of the pathogen's virulence and its universal resistance to most antimicrobial agents. Even after early Tenckhoff catheter removal, the transport property of the peritoneum is often irreversibly damaged, leading to permanent technique failure. We report 2 patients with CAPD-associated peritonitis due to A. xylosoxidans sp. xylosoxidans who were successfully cured with a combination of piperacillin and tazobactam. One of them subsequently returned uneventfully to CAPD.
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Lui SL, Hui CK, Chan TM, Lo WK, Lai KN. Progressive demyelinating neuropathy after initiation of continuous ambulatory peritoneal dialysis--report of two cases. Clin Nephrol 2001; 56:407-10. [PMID: 11758015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
We report on two patients who developed rapidly progressive demyelinating neuropathy within 6 to 10 weeks after the initiation of continuous ambulatory peritoneal dialysis. The neuropathy in one patient resolved after kidney transplantation while that of the other patient improved with immunosuppressive therapy. The close temporal relationship between the initiation of peritoneal dialysis and the onset of neuropathy suggests that these two events may be causally related.
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Lai KN, Ho SK, Leung J, Tang SC, Chan TM, Li FK. Increased survival of mesothelial cells from the peritoneum in peritoneal dialysis fluid. Cell Biol Int 2001; 25:445-50. [PMID: 11401332 DOI: 10.1006/cbir.2000.0664] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Peritonitis remains the most important factor in patient morbidity and technical failure associated with continuous ambulatory peritoneal dialysis (CAPD). In vitro examination of bacterial infection of cultured human peritoneal mesothelial cells (HPMC) is an attractive approach to the study of peritonitis in CAPD, yet there are few reports on this subject. Previous studies have shown two limitations: (i) cell cultures of HPMC lasted for days only when incubated in culture medium and (ii) short-term studies of <30 min were done in HPMC when incubated with peritoneal dialysis fluid (PDF). Human peritoneal mesothelial cells, maintained in a conventional single chamber culture system with PDF alone, were unable to survive more than 40 min. The present study was designed to prolong the viability of HPMC cultured in PDF, with the object of using cells under different conditions, such as that of simulating CAPD. HPMC were cultured using plastic microtiter plates, where they were grown to confluence and growth was arrested. PDF containing different concentrations of NaHCO3and human serum albumin was added. Cell viability after exposure for up to 24 h was measured by trypan blue, Cell Death Detection ELISA and Annex-V flow cytometry. The data confirmed the 'toxic' effect of PDF, with cell viability being <40% after 2 h incubation in 4.25% glucose in PDF. However, the survival time of HPMC increased significantly in 4.25% glucose PDF at a physiological pH and even further after the addition of human albumin. These experimental conditions simulating CAPD may allow future in vitro studies of mesothelial physiology and peritonitis related to CAPD treatment.
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Lui SL, Chan LY, Zhang XH, Zhu W, Chan TM, Fung PC, Lai KN. Effect of mycophenolate mofetil on nitric oxide production and inducible nitric oxide synthase gene expression during renal ischaemia-reperfusion injury. Nephrol Dial Transplant 2001; 16:1577-82. [PMID: 11477158 DOI: 10.1093/ndt/16.8.1577] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND Recent animal data suggest that inducible nitric oxide synthase (iNOS) derived nitric oxide (NO) plays an important role in the pathogenesis of renal ischaemia-reperfusion injury (IRI) and that inhibition of iNOS ameliorates IRI. Mycophenolate mofetil (MMF), a lymphocyte selective anti-proliferative agent, has been shown to inhibit NO production in vitro. The aim of this study is to evaluate the effect of MMF on NO production and iNOS gene expression in vivo during renal IRI. METHODS Renal IRI was induced by clamping the left renal pedicle of male BALB/c mice for 30 min, followed by 15 min of reperfusion. The mice received placebo or MMF at 40, 80 or 120 mg/kg/day by oral gavage for 5 days before the operation. Sham-operated mice served as the operation control. The amount of NO produced and the level of iNOS gene expression in the kidney tissue during IRI was assessed by spin trapping electron paramagnetic resonance (EPR) spectroscopy and semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) respectively. RESULTS In the sham-operated kidneys, only low levels of NO and iNOS mRNA were detected. In mice with renal IRI, the amount of NO detected was significantly increased, which was reduced in a dose dependent fashion by pre-treatment with MMF. Pre-treatment with MMF also substantially reduced iNOS gene expression in the kidney tissue. CONCLUSIONS We conclude that pre-treatment with MMF inhibits the production of NO and the induction of iNOS gene expression in the kidney during IRI. These results suggest that MMF might have the potential to ameliorate renal IRI.
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Tang S, Leung JC, Lam CW, Lai FM, Chan TM, Lai KN. In vitro studies of aquaporins 1 and 3 expression in cultured human proximal tubular cells: upregulation by transferrin but not albumin. Am J Kidney Dis 2001; 38:317-30. [PMID: 11479158 DOI: 10.1053/ajkd.2001.26097] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Dysregulated renal water handling is a cardinal feature of nephrotic syndrome that has been shown in animal models of experimental nephrosis to mediate renal aquaporin (AQP) expression. However, data on the effect of proteinuria on the proximal tubule, which is heavily vested with AQP1 and therefore may participate in water homeostasis, are limited. To investigate this, we exposed primary human proximal tubular epithelial cells (PTECs) to two key proteinuric components shown to perturb tubule function: human serum albumin and transferrin. Using reverse-transcriptase polymerase chain reaction and immunocytochemical techniques, PTECs in the quiescent state were found to express AQP3 in addition to AQP1 gene and protein, which was also validated in a human proximal tubule cell line, HK-2. Immunohistochemical staining localized AQP1 synthesis to the apical and basolateral membranes and AQP3 synthesis to the basolateral membrane of proximal tubule epithelium. Transferrin in doses reaching nephrotic range upregulated PTEC transcription and translation of both AQP1 and AQP3 in a time- and dose-dependent manner. After 24 hours of stimulation, transferrin led to a 2.4- and 2.2-fold increase in AQP1 and APQ3 messenger RNA expression, whereas protein synthesis surged by 40.7% +/- 2.48% and 24.2% +/- 0.9% compared with control, respectively. These effects were not observed with albumin challenge and were not caused by osmolality fluctuation with transferrin treatment. In summary, our novel finding of AQP3 in PTECs indicates a role for AQP3 in proximal tubule water reabsorption. The pathophysiological significance of heightened AQP1 and AQP3 expression in PTECs on protein challenge as occurs in the nephrotic state requires further investigation.
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Tse KC, Li FK, Tang S, Lam MF, Chan TM, Lai KN. Delusion of worm infestation associated with clarithromycin in a patient on peritoneal dialysis. Perit Dial Int 2001; 21:415-6. [PMID: 11587409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023] Open
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234
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Lai KN, Ho K, Cheung RC, Lit LC, Lee SK, Fung KS, Tong MK, Lam CW. Effect of low molecular weight heparin on bone metabolism and hyperlipidemia in patients on maintenance hemodialysis. Int J Artif Organs 2001; 24:447-55. [PMID: 11510916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
The effect of low molecular weight heparin (LMWH) on serum lipid profile in hemodialysis remains controversial and its effect on bone metabolism has not been studied. A crossover study was conducted in 40 patients on stable hemodialysis using unfractionated heparin (UFH) for more than 24 months. These patients were then treated with a LMWH (nadroparin-Ca) for 8 months during hemodialysis and subsequently switched back to UFH for 12 months. Serum lipid profile, biochemical markers for bone metabolism, and bone densitometry (BMD) were monitored at four-month intervals while all medications remained unchanged. Cholesterol (TC), triglyceride (TG), low-density lipoprotein-cholesterol (LDL-C), lipoprotein(a) (Lp(a)), apolipoprotein B (Apo B) were raised in 35%, 29%, 12%, 24% and 24% of patients respectively. High-density lipoprotein-cholesterol (HDL-C) and apolipoprotein A1 (Apo A-1) were reduced in 47% and 9% of patients. Bone-specific alkaline phosphatase (BALP) and intact osteocalcin (OSC), both reflecting osteoblastic activity, were raised in 65% and 94% of patients. Tartrate-resistant acid phosphatase (TRACP) reflecting osteoclastic activity and parathyroid hormone (PTH) were elevated in 35% and 88% of patients. Following LMWH treatment, TC, Tg, Lp(a) and Apo B were reduced by 7%, 30%, 21% and 10% respectively (p<0.05 or <0.01) while Apo A-1 were raised by 7% (p<0.01). Simultaneously, TRACP was reduced by 13% (p<0.05). These biochemical changes were detected soon after 4 months of LMWH administration. Although BMD values in our patients were lower than those of age-matched normal subjects, significant changes were not observed with LMWH treatment. After switching back to UFH for hemodialysis, these biochemical indices reverted to previous values during UFH treatment with a significant higher level in TC and Apo B while serum Apo A-1 remained elevated. Our study suggests LMWH may partially alleviate hyperlipidemia and, perhaps, osteoporosis associated with UFH administration in patients on maintenance hemodialysis.
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Tomino Y, Suzuki S, Azushima C, Shou I, Iijima T, Yagame M, Wang LN, Chen HC, Lai KN, Tan SY, Kim MJ. Asian multicenter trials on urinary type IV collagen in patients with diabetic nephropathy. J Clin Lab Anal 2001; 15:188-92. [PMID: 11436201 PMCID: PMC6807741 DOI: 10.1002/jcla.1026] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
To investigate the changes of renal type IV collagen turnover in diabetic nephropathy, urinary type IV collagen was measured by a highly sensitive one-step sandwich enzyme immunoassay (EIA). Urinary samples were obtained from 698 diabetic patients and 191 healthy adults. Among the patients, 264 had urinary albumin levels of less than 29 mg/g.creatine (Cr) (Stage I: normoalbuminuric stage), 169 had microalbuminuria from 30 to 299 mg/g.Cr (Stage II: microalbuminuric stage), 84 patients had macroalbuminuria of more than 300 mg/g.Cr and serum Cr of less than 1.1 mg/dl (Stage IIIA: macroalbuminuric stage without renal dysfunction), 97 had macroalbuminuria of more than 300 mg/g.Cr and serum Cr of more than 1.2 mg/dl (Stage IIIB: macroalbuminuric stage with renal dysfunction), and 84 had renal failure (Stage IV). The levels of urinary type IV collagen in Stages II, IIIA, IIIB, and IV were significantly higher than those in Stage I (P < 0.0001). The level of urinary type IV collagen in Stage I (5.00 +/- 0.23 microg/g.Cr; mean +/- SE) was also higher than that in normal adults (3.44 +/- 0.11 microg/g.Cr; mean +/- SE). These levels increased gradually due to progression of the clinical stage of diabetic nephropathy. It appears that the levels of urinary type IV collagen can be a useful marker for detecting renal injuries in diabetes according to our Asian multicenter trials.
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Lai KN, Li FK, Yui Lan H, Tang S, Tsang AWL, Chan DTM, Leung JC. Expression of aquaporin-1 in human peritoneal mesothelial cells and its upregulation by glucose in vitro. J Am Soc Nephrol 2001; 12:1036-1045. [PMID: 11316863 DOI: 10.1681/asn.v1251036] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Aquaporin (AQP) is a family of water channels that are highly selective for the passage of water and occasionally glycerol. In previous studies, only AQP1 was found in human peritoneal endothelial cells in both control subjects and patients on peritoneal dialysis. As human peritoneal mesothelial cells (HPMC) play an important role in dialysis adequacy and fluid balance in continuous ambulatory peritoneal dialysis patients, this study examined whether AQP1 is present in HPMC. It was found that AQP1 mRNA and protein are present in HPMC constitutively. The localization of AQP1 protein in peritoneal mesothelial cells was confirmed by double immunohistochemical staining of the mesothelial lining of human peritoneal membrane. More important, the expression of AQP1 in HPMC is not constitutive and the transcription and biosynthesis of AQP1 in HPMC is inducible by osmotic agents such as glucose and mannitol. There was significant enhancement of AQP1 biosynthesis upon exposure to glucose in a time- and dose-dependent manner (P < 0.0001). Similar findings were observed in the AQP1 biosynthesis by an endothelial cell line, EA.hy 926. Of particular interest, the upregulation in AQP1 mRNA or biosynthesis in mesothelial cells was always significantly higher than that of endothelial cells when the experiments were conducted under identical settings (P < 0.001). AQP1 expression in HPMC was demonstrated for the first time. Osmotic agents upregulate both mRNA and protein expression of this aquaporin. The role of AQP1 in HPMC in maintaining the ultrafiltration of the peritoneal membrane is potentially of clinical interest.
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Li FK, To CH, Leung JK, Chan TM, Lai KN. Electrophysiology and glucose transport of human peritoneal mesothelial cells: implications for peritoneal dialysis. Perit Dial Int 2001; 21:115-21. [PMID: 11330553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023] Open
Abstract
OBJECTIVE To elucidate ionic and glucose transport across human peritoneal mesothelium, we utilized an Ussing chamber setup and studied the electrophysiological characteristics and tissue permeabilities of human peritoneal mesothelial cells (HPMC) to L- and D-glucose. METHODS Human mesothelial cells were grown on polyester filters (snapwell; Costar, Cambridge, MA, U.S.A.) that, upon confluence, were fitted into Ussing chambers. Transmesothelial resistance and resting potential were determined using electrophysiological techniques. Radiolabeled glucose was added to one side of the chamber and the permeabilities determined by serial sampling in the receptive compartment. RESULTS The transmesothelial potential and resistance were 0.54 +/- 0.07 mV (apical positive) and 20.4 +/- 3.2 ohms x cm2 respectively (mean +/- SEM, n = 36). The course of overall transfer of D- and L-glucose was examined using L-glucose as a positive diffusion-plus-leak marker. The permeabilities of HPMC to D-glucose were 3.00 +/- 0.26 cm/sec (apical-to-basolateral) and 3.25 +/- 0.27 cm/sec (basolateral-to-apical) [n = 6 experiments, p = not significant (NS)], which were not different from those of L-glucose: 3.00 +/- 0.30 cm/sec (apical-to-basolateral) and 2.71 +/- 0.24 (basolateral-to-apical) (n = 6 experiments, p = NS). CONCLUSIONS The transepithelial resistance of HPMC is low and the ionic gradient, although it exists, is small and inconsequential. Passive paracellular flow accounts for the majority of transmesothelial glucose transport. The existence of a large paracellular shunt precludes the mesothelial membrane as a clinically relevant osmotic barrier.
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Lui SL, Luk WK, Cheung CY, Chan TM, Lai KN, Peiris JS. Nosocomial outbreak of parvovirus B19 infection in a renal transplant unit. Transplantation 2001; 71:59-64. [PMID: 11211196 DOI: 10.1097/00007890-200101150-00010] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Parvovirus B19 (B19) infection is known to cause chronic infection leading to anemia in immunocompromised patients. Although nosocomial B19 infections in immunocompetent patients have been documented, no outbreaks in immunocompromised patients have been previously reported. Whether transmission can occur from a patient with chronic infection is also unknown. METHODS An outbreak of B19 infection in a renal transplant unit was investigated by molecular analysis of the virus strains and a case-control study. RESULTS Three patients had genetically identical virus strains suggesting the occurrence of nosocomial transmission. The index case transmitted infection many weeks after the onset of her clinical symptoms. Other patients at risk of acquiring infection were those most intensively immunosuppressed. Viral load in the serum correlated with the hematological response. A rebound in the viral load was associated with clinical relapse and the failure of i.v. immunoglobulin therapy. CONCLUSION Nosocomial transmission of B19 can occur from immunocompromised patients even when they are in the chronic stage of the infection. The clinical and virological response to i.v. immunoglobulin therapy is variable and depends on the overall level of immunosuppression of the patient.
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Tang S, Lai KN, Chan TM, Lan HY, Ho SK, Sacks SH. Transferrin but not albumin mediates stimulation of complement C3 biosynthesis in human proximal tubular epithelial cells. Am J Kidney Dis 2001; 37:94-103. [PMID: 11136173 DOI: 10.1053/ajkd.2001.20593] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Complement is increasingly implicated in the pathogenesis of progressive renal disease resulting from persistent proteinuria. We have previously shown that apical serum proteins stimulate C3 in cultured human proximal tubular epithelial cells (PTECs), and that the stimulant is a nonalbumin compound of 30 to 100 kd. We postulated in this study that transferrin and apotransferrin, also important components of proteinuric urine in this molecular-weight range, might be the culprit. Human PTECs were obtained by differential sieving of renal cortical tissue from the normal pole of tumor nephrectomy specimens and characterized to be predominantly of proximal tubular origin. Complement C3 messenger RNA (mRNA) expression was analyzed in confluent growth-arrested PTEC monolayers in media containing different concentrations (2.5 to 20 mg/mL) of transferrin by reverse transcription and polymerase chain reaction. Pure human albumin was used as a control protein. C3 protein secretion was detected and quantified by a sandwich enzyme-linked immunosorbent assay on cell culture supernatants after distinct time points. Transferrin enhanced the rate of C3 secretion in a dose-dependent manner, reaching maximal stimulation at doses of 10 mg/mL. Selected experiments using the Transwell technique showed that C3 release was predominantly apical in the resting state. The addition of 10 mg/mL of transferrin apically but not basolaterally stimulated both apical and basolateral C3 secretion and increased the basolateral-apical ratio of C3 secretion from 0.45 +/- 0.16 to 0.93 +/- 0.24 (P: < 0.02). Constitutive C3 mRNA expression was upregulated by transferrin in a time- and dose-dependent fashion, reaching a peak after 24 hours. A similar degree of C3 upregulation was reproduced when iron-poor transferrin, apotransferrin, was used instead. These results indicate that C3 synthesis in PTECs is upregulated by transferrin, for which protein rather than iron moiety may account for the observed effects. These findings provide evidence linking proteinuria with overexpression of tubular complement.
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Leung JC, Tang SC, Lam MF, Chan TM, Lai KN. Charge-dependent binding of polymeric IgA1 to human mesangial cells in IgA nephropathy. Kidney Int 2001; 59:277-85. [PMID: 11135081 DOI: 10.1046/j.1523-1755.2001.00489.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND IgA nephropathy (IgAN) is characterized by raised serum IgA1 and predominant mesangial IgA1 deposits of polymeric nature. The mechanism of polymeric IgA1 (pIgA1) deposition in the kidney mesangium is poorly understood in IgAN. It has been suggested that increased sialic acid content and anionic charge of the pIgA1 molecules may be operational in the IgA1 deposition in human mesangial cells (HMCs). The present study examined the binding of pIgA1 with different surface charges to HMCs. The binding characteristics of IgA1 to HMCs in the presence of polycation (poly-L-lysine) or polyanion (heparin) were also investigated. METHODS IgA1 was purified in sera from patients with IgAN and from healthy controls by jacalin affinity chromatography. IgA1 was further separated into pIgA1 and monomeric IgA1 (mIgA1) by fast protein liquid chromatography (FPLC). pIgA1 or mIgA1 with different net charges on their surface were resolved by ion exchange chromatography (IEC) with a Mono Q column. The binding characteristics of pIgA1 and mIgA1 to HMCs in the presence or absence of polycation or polyanion were examined by flow cytometry. RESULTS In patients with IgAN, the absolute amount of mIgA1 and pIgA1 is significantly higher than that of healthy controls (P < 0. 001). There was significant increase in binding of pIgA1 from patients with IgAN to HMC and cell lysate. pIgA1 that interacted strongly with the ion exchanger also bound more to HMCs when compared with IgA1 interacted weakly with the ion exchanger (P < 0. 001). The anionic charged pIgA1 from patients was significantly higher than that of healthy controls (P < 0.001). Preincubation with poly-L-lysine increased the binding of pIgA1 to HMCs. The binding of pIgA1 to HMCs was decreased by preincubation with heparin. CONCLUSIONS The binding of IgA to HMCs is charge dependent. Polymeric IgA with the highest net negative charge binds more to HMCs. Preincubation with polyanion decreased the binding of polymeric IgA to HMCs. These results suggest an important role for anionic charge in IgA1 deposition onto the kidney mesangial cells.
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Wang AY, Yu AW, Li PK, Lam PK, Leung CB, Lai KN, Lui SF. Factors predicting outcome of fungal peritonitis in peritoneal dialysis: analysis of a 9-year experience of fungal peritonitis in a single center. Am J Kidney Dis 2000; 36:1183-92. [PMID: 11096043 DOI: 10.1053/ajkd.2000.19833] [Citation(s) in RCA: 131] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Fungal peritonitis causes significant morbidity and mortality for patients undergoing continuous ambulatory peritoneal dialysis (CAPD). We retrospectively reviewed 70 episodes of fungal peritonitis in a single center over the last 9 years in 896 CAPD patients. Seventy percent of the episodes of fungal peritonitis were caused by Candida species, among which 50% were Candida parapsilosis. As a result of fungal peritonitis, 44% of the patients died, whereas further peritoneal dialysis failed in 14%, requiring a change to long-term hemodialysis. Only 37% managed to continue CAPD. The remaining 5% either underwent transplantation or were lost to follow-up. We identified the factors associated with poor outcome, namely mortality and technique failure. The presence of abdominal pain, bowel obstruction, and a catheter remaining in situ were significantly associated with greater mortality. Abdominal pain, antibiotic use within 3 months before fungal peritonitis, and complication by bowel obstruction were associated with greater technique failure. In choosing antifungal agents with catheter removal, oral fluconazole alone appears equally as effective as combined oral fluconazole with 5-flucytosine for peritonitis caused by Candida species. For peritonitis caused by species other than Candida, the choice of antifungal therapy needs to be individualized, based on fungal species and sensitivities.
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Wong TY, Szeto CC, Lai KB, Lam CW, Lai KN, Li PK. Longitudinal study of peritoneal membrane function in continuous ambulatory peritoneal dialysis: relationship with peritonitis and fibrosing factors. Perit Dial Int 2000; 20:679-85. [PMID: 11216559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023] Open
Abstract
BACKGROUND The peritoneal equilibration test (PET) is a useful assessment of peritoneal function in continuous ambulatory peritoneal dialysis (CAPD) patients. However, the natural course of longitudinal change in peritoneal transport is not well defined. PATIENTS We studied 105 unselected CAPD patients. Average age at enrollment was 50.7 +/- 11.3 years. METHODS A PET was performed at enrollment. Peritoneal transport was expressed as dialysate-to-plasma creatinine ratio at 4 hours (DIP). Fibrosing factors and mesothelial cell markers, including TGFbeta, epidermal growth factor (EGF), platelet-derived growth factor (PDGF), hyaluronan, and cancer antigen 125 (CA125), were measured in overnight peritoneal dialysate effluent (PDE). Patients were followed for two years. Peritonitis episodes were recorded. Severe peritonitis was defined as an episode that required catheter removal or antibiotic therapy for more than 3 weeks. After two years, 75 patients were still alive and on CAPD. RESULTS The PET was repeated in 64 patients, of whom 35 were male and 9 had diabetes. The change in D/P over two years was represented as AD/P. No significant change in peritoneal transport was seen after two years (D/P: 0.56 +/- 0.12 vs 0.55 +/- 0.13). A centripetal pattern of change in D/P was observed. The deltaD/P had normal distribution and was inversely correlated with D/P at baseline (r = -0.427, p < 0.005). Both results suggest a regression-to-mean phenomenon. The deltaD/P had no significant correlation with the total number of peritonitis episodes (Spearman r = 0.052, p = 0.74), but after severe peritonitis, affected patients had higher deltaD/P than patients who experienced no severe infection (0.040 +/- 0.136 vs -0.032 +/- 0.120, p < 0.05). For patients with no episodes of severe peritonitis (n = 47), deltaD/P was weakly correlated with baseline TGFbeta level (r = -0.506, p < 0.01). No correlation was seen between the levels of other fibrosing factors and change in peritoneal transport. CONCLUSIONS Our findings suggest that the centripetal change of peritoneal transport probably reflects a regression-to-mean phenomenon. Peritoneal transport increases after severe peritonitis. The role of TGFbeta levels in PDE with regard to longitudinal change in peritoneal transport requires further study.
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Tang S, Chan TM, Lui SL, Li FK, Lo WK, Lai KN. Risk factors for avascular bone necrosis after renal transplantation. Transplant Proc 2000; 32:1873-5. [PMID: 11119978 DOI: 10.1016/s0041-1345(00)01471-8] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Siu CW, Chan TM, Li FK, Choy BY, Lui SL, Lo CY, Tang S, Lo WK, Lai KN. Association between anti-thymocyte globulin administration and cytomegalic virus infection and/or CMV disease in cadaveric renal allograft recipients. Transplant Proc 2000; 32:1932-4. [PMID: 11120007 DOI: 10.1016/s0041-1345(00)01499-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Abstract
A 35-year-old patient with blood group AB developed hemolysis 1 week after receiving a blood group B cadaveric kidney transplant. The patient's serum was shown to contain anti-A antibody, which was likely to have been derived from passenger lymphocytes transplanted concurrently with the graft. The alloimmune hemolysis subsided spontaneously without treatment. The present case underscores the potential complication of ABO blood group-compatible but nonidentical organ transplantation. Clinical vigilance is important to differentiate from other more sinister causes of posttransplant hemolysis.
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Lam MF, Li FK, Choy BY, Tang S, Lo WK, Lui SL, Chu SM, Tam PC, Chan TM, Lai KN. The impact of the establishment of a multiorgan transplantation program on cold ischemia time and delayed graft function in renal transplantation. Transplant Proc 2000; 32:1611-2. [PMID: 11119859 DOI: 10.1016/s0041-1345(00)01451-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Tang S, Tso WK, Li JH, Li CL, Chan TM, Lai KN. Clinical outcome following percutaneous transluminal angioplasty for transplant renal artery stenoses. Transplant Proc 2000; 32:1889-91. [PMID: 11119987 DOI: 10.1016/s0041-1345(00)01479-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Chan TM, Li FK, Tang CS, Wong RW, Fang GX, Ji YL, Lau CS, Wong AK, Tong MK, Chan KW, Lai KN. Efficacy of mycophenolate mofetil in patients with diffuse proliferative lupus nephritis. Hong Kong-Guangzhou Nephrology Study Group. N Engl J Med 2000; 343:1156-62. [PMID: 11036121 DOI: 10.1056/nejm200010193431604] [Citation(s) in RCA: 638] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
BACKGROUND The combination of cyclophosphamide and prednisolone is effective for the treatment of severe lupus nephritis but has serious adverse effects. Whether mycophenolate mofetil can be substituted for cyclophosphamide is not known. METHODS In 42 patients with diffuse proliferative lupus nephritis we compared the efficacy and side effects of a regimen of prednisolone and mycophenolate mofetil given for 12 months with those of a regimen of prednisolone and cyclophosphamide given for 6 months, followed by prednisolone and azathioprine for 6 months. Complete remission was defined as a value for urinary protein excretion that was less than 0.3 g per 24 hours, with normal urinary sediment, a normal serum albumin concentration, and values for serum creatinine and creatinine clearance that were no more than 15 percent above the base-line values. Partial remission was defined as a value for urinary protein excretion that was between 0.3 and 2.9 g per 24 hours, with a serum albumin concentration of at least 30 g per liter. RESULTS Eighty-one percent of the 21 patients treated with mycophenolate mofetil and prednisolone (group 1) had a complete remission, and 14 percent had a partial remission, as compared with 76 percent and 14 percent, respectively, of the 21 patients treated with cyclophosphamide and prednisolone followed by azathioprine and prednisolone (group 2). The improvements in the degree of proteinuria and the serum albumin and creatinine concentrations were similar in the two groups. One patient in each group discontinued treatment because of side effects. Infections were noted in 19 percent of the patients in group 1 and in 33 percent of those in group 2 (P = 0.29). Other adverse effects occurred only in group 2; they included amenorrhea (in 23 percent of the patients), hair loss (19 percent), leukopenia (10 percent), and death (10 percent). The rates of relapse were 15 percent and 11 percent, respectively. CONCLUSIONS For the treatment of diffuse proliferative lupus nephritis, the combination of mycophenolate mofetil and prednisolone is as effective as a regimen of cyclophosphamide and prednisolone followed by azathioprine and prednisolone but is less toxic.
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