Completely reversed acute rejection is not a significant risk factor for the development of chronic rejection in renal allograft recipients.

Although acute rejection (AR) has been shown to correlate with decreased long-term renal allograft survival, we have noted AR in recipients who subsequently had stable function for more than 5 years. We reviewed 109 renal graft recipients with a minimum of 1 year graft survival and follow-up of 5-8 years. Post-transplant sodium iothalamate clearances (IoCI) measured at 3 months and yearly thereafter were used to separate recipients into 2 groups. In 61 patients (stable group), there was no significant decrease ( > 20 % reduction in IoCl over 2 consecutive years) in IoCl. Forty-eight patients had significant declines in IoCl (decline group). Groups were compared for incidence, severity, timing, and completeness of reversal of AR. Rejection was considered completely reversed if the post-AR serum creatinine (Scr) returned to or below the pre-AR nadir Scr after anti-rejection therapy. The incidence of AR was not significantly different between groups (47% vs 52%). A trend toward a lower mean number of AR episodes per patient was noted in the stable group (0.69 vs 1.04, P = 0.096), but the timing of AR was not different. Steroid-resistant AR occurred in approximately 25 % of both groups. A striking difference was seen in complete reversal of AR, with the stable group having 100% (42/42 episodes of AR in 29 patients) complete reversal whereas only 32 % (8/25) of the patients in the decline group had complete reversal (P < < 0.001). Of 8 declining patients with complete reversal, graft loss was due to chronic rejection (CR) in only 3. Seventeen declining patients had incomplete reversal of AR, and 82 % (14/17) lost their grafts to CR. Overall, only 8% (3/37) of the recipients with complete reversal of AR developed CR. No patients with incompletely reversed AR had stable long-term function as measured by IoCl. AR is not invariably deleterious to long-term renal graft function if each episode of AR can be completely reversed.

Changing incidence of glomerular diseases in adults.

Studies performed at large metropolitan medical centers have reported an increasing incidence of idiopathic focal segmental glomerulosclerosis (FSGS) in adults. To determine whether a similar trend occurs in small urban and rural communities and to determine the role of race in these observations, we reviewed the patient records of all adults who underwent renal biopsies at our institution over the 20-year period from 1974 to 1994. The patients were grouped for analysis in 5-year intervals, 1975 to 1979, 1980 to 1984, 1985 to 1989, and 1990 to 1994, for the following diagnoses: FSGS, membranous nephropathy (MN), minimal change nephropathy (MCN), membranoproliferative glomerulonephritis (MPGN), immunoglobulin A (IgA) nephropathy, chronic glomerulonephritis, diabetic nephropathy, hypertensive nephrosclerosis, and chronic interstitial nephritis. Patients with secondary causes for these lesions were excluded. The relative frequency of FSGS increased from 13.7% during 1975 to 1979 to 25% during 1990 to 1994 (P < 0.05). The relative frequency of MN decreased from 38.3% during 1975 to 1979 to 14.5% during 1990 to 1994 (P < 0.01). There were no changes in the frequencies of MCN, MPGN, IgA nephropathy, chronic glomerulonephritis, diabetic nephropathy, hypertensive nephrosclerosis, or chronic interstitial nephritis over the 20-year period. However, there was a significant increase in the percentage of blacks with FSGS, from 0% in 1975 to 1979 to 22.6% in 1990 to 1994, and an increased percentage of Hispanics with FSGS, from 0% in 1975 to 1979 to 21.3% in 1990 to 1994 (P < 0.05). The modest increase in whites with FSGS did not reach statistical significance. The incidence of MN in blacks and whites decreased over the 20-year period. In the last 5 years, 15 patients per year had FSGS compared with 7 patients per year with MN (P < 0.05). No changes in age or sex between groups or over time accounted for these results. We conclude that FSGS is now diagnosed twice as often as MN and is the most common idiopathic glomerular disease at our hospital. Reasons for this increase include the emergence of FSGS in both Hispanics and blacks, with a modest increase of FSGS in whites. The increase in FSGS in the three most common races in our community suggests that factors other than genetic, perhaps environmental, have a role in the pathogenesis of FSGS.

Transplantation and 2-year follow-up of kidneys procured from a cadaver donor with a history of lupus nephritis.

BACKGROUND: Two patients underwent cadaver transplantation with kidneys from a donor with a history of World Health Organization Class IV/V lupus nephritis, and we report their clinical and pathological outcome. METHODS: The donor had a diagnosis of lupus nephritis made by renal biopsy 5 years before donation. At the time of donation, a biopsy was performed on the donor and on one of the recipients at 2 months and 1 year after the transplant. RESULTS: Both recipients underwent uneventful renal transplantation. On the first postoperative day, the donor's final pathological results became available. Although the frozen section seemed to be quite benign, the permanent sections revealed World Health Organization Class II/V lupus nephritis, with full house immunofluorescence and multiple electron dense deposits. Biopsies were performed on recipient #2 at 8 weeks and 1 year after the transplant. These revealed marked diminution followed by complete resolution of all tubular reticular structures and deposits as well as immunofluorescent activity. Both recipients remain with normal renal function and urinalysis at 3 years after the transplant. CONCLUSION: Although a history of clinically significant renal disease has been considered an absolute contraindication to kidney donation, with appropriate workup and caution, select patients may still be considered, which would increase the potential donor pool.

Trough serum vancomycin levels predict the relapse of gram-positive peritonitis in peritoneal dialysis patients.

We reviewed 31 episodes of gram-positive peritonitis that occurred in our peritoneal dialysis population between 1990 and 1993 in an attempt to identify the risk factor(s) for peritonitis relapse. All patients were treated with 4 weekly doses of intravenous vancomycin. Vancomycin doses no. 1 and 2 were based on body weight (15 mg/kg with a 1-g minimum); vancomycin doses no. 3 and 4 were adjusted in an attempt to maintain the trough serum vancomycin level at greater than 12 mg/L. Nine peritonitis episodes complicated by a relapse were identified. Peritonitis episodes preceding a relapse were similar to relapse-free episodes with respect to patient age, diabetes, peritoneal dialysis modality, duration of peritoneal dialysis treatment, residual urea clearance, peritoneal fluid cell count, causative organism, and weekly vancomycin dose. However, cumulative 4-week mean trough vancomycin levels were consistently lower during peritonitis episodes preceding a relapse (7.8 +/- 0.6 mg/L during relapse-prone episodes v 13.7 +/- 0.9 mg/L during relapse-free episodes; P = 0.0004). Furthermore, relapses developed during nine of 14 peritonitis episodes demonstrating a 4-week mean trough vancomycin level less than 12 mg/L compared with zero of 17 episodes with a 4-week trough level greater than 12 mg/L (P < 0.05). The detection of a low initial 7-day trough vancomycin level also was a useful marker for subsequent peritonitis relapse. In 13 peritonitis episodes associated with an initial trough level less than 9 mg/L, nine were complicated by a relapse.(ABSTRACT TRUNCATED AT 250 WORDS)

Association of post-renal transplant erythrocytosis and microalbuminuria: response to angiotensin-converting enzyme inhibition.

Angiotensin-converting enzyme (ACE) inhibitor therapy has recently been shown to be effective in the treatment of post-renal transplant erythrocytosis (PTE). In an attempt to assess the effect of drug treatment on serum erythropoietin level, glomerular filtration rate, and urinary protein excretion, we prospectively evaluated 8 consecutive cadaveric renal transplant recipients with PTE treated with ACE inhibitor therapy for 3 months. In response to ACE inhibition, the mean hematocrit (HCT) value decreased from 53.7 +/- 0.6% before treatment to 42.7 +/- 2.2% at the conclusion of the study (p = 0.03). However, 1 patient failed to respond to ACE inhibition (HCT > 50%), and 2 patients with PTE developed anemia (HCT < 35%) while maintained on drug treatment. Although the mean serum erythropoietin level decreased during ACE inhibition (from 22.8 +/- 8.4 to 9.4 +/- 5.3 mU/ml; p = 0.06), a consistent change in individual erythropoietin levels was not identified. At the conclusion of the study, the serum erythropoietin levels were undetectable in 4 patients, decreased in 1, unchanged in 2, and increased in the only patient with PTE who failed to respond to drug treatment. All patients tolerated the ACE inhibitor therapy without developing cough or hyperkalemia. In addition, serum creatinine levels, 125I-iothalamate clearances, and mean arterial blood pressures were unchanged throughout the study. Microalbuminuria (spot urinary albumin/creatinine ratio between 30 and 200 mg/g) developed in 5 patients with PTE and coincided with the onset of erythrocytosis (25.2 +/- 7 mg/g before PTE and 76.3 +/- 36.7 mg/g at the time of PTE detection).(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of IGF-I on renal function in patients with chronic renal failure.

Insulin-like growth factor I (IGF-I) has been shown to increase glomerular filtration rate and renal plasma flow in rats and humans with normal renal function. However, rats with reduced renal function are resistant to these effects. To determine whether IGF-I affects glomerular filtration rate and renal plasma flow in humans with reduced renal function, we administered recombinant human IGF-I (rhIGF-I) to patients with moderate chronic renal failure. Four patients whose baseline inulin clearances were 21.9, 23.2, 34.9, and 55.1 ml.min-1.1.73 m-2 were placed on a 1 g.kg-1.day-1 protein diet and studied over a 10-day period (0-10). On days 4-7, 100 micrograms/kg of rhIGF-I was subcutaneously administered twice daily to the patients. The effects of rhIGF-I on levels of circulating IGF-I, inulin clearance, p-aminohippurate (PAH) clearance, kidney volume, plasma glucose, plasma and urine calcium and phosphate, and urine sodium and protein were determined. Administration of rhIGF-I increased levels of circulating IGF-I, inulin clearances, PAH clearances, and kidney size in each of the four patients receiving the growth factor. IGF-I did not cause weight gain, natriuresis, proteinuria, or hypoglycemia. Plasma calcium and phosphate were not affected by rhIGF-I. However, the percent tubular reabsorption of filtered phosphate was increased. We conclude that administration of rhIGF-I can enhance glomerular filtration rate and renal plasma flow at least in some humans with moderately reduced renal function. The enhancement is associated with an increase in kidney volume.

Growth hormone and the kidney: a case presentation and review of the literature.

Hypersomatotropism is accompanied by a significant increase in GFR and RPF. A case of a patient with acromegaly and supranormal renal function as measured by inulin and p-aminohippurate clearances is reported. The literature regarding the effects of growth hormone on renal function is reviewed, and the potential mechanisms of action and therapeutic implications of these effects are discussed.

Cloning of a cDNA encoding phosphoenolpyruvate carboxykinase from Haemonchus contortus.

Biochemical and metabolic data have led to the conclusion that the enzyme phosphoenolpyruvate carboxykinase (PEPCK; EC 4.1.1.32) contributes to a critical point of divergence in energy conservation pathways between mammals and nematodes. To facilitate the determination of the molecular basis for host vs parasite differences in PEPCK, we have cloned a cDNA encoding this enzyme from a parasitic nematode of ruminants, Haemonchus contortus. H. contortus PEPCK was cloned by functional complementation of a PEPCK-, malic enzyme- strain of Escherichia coli (E1786) using an egg stage H. contortus cDNA library in lambda ZAPII. Selection was for growth on malate as the sole carbon source (malate+ phenotype). We isolated a plasmid, pPEPCK, which reproducibly confers a malate+ phenotype in E1786. The sequence of the 2.0-kb EcoRI insert of pPEPCK predicts a 612-amino acid protein which shows about 74% similarity to Drosophila melanogaster and chicken PEPCK. Extracts of E1786[pPEPCK], but not E1786, contain IDP- or GDP-dependent PEPCK enzyme activity. Sequence analysis revealed that the open reading frame (ORF) in pPEPCK lacked a 5' initiation codon and was probably expressed as an in-frame fusion protein with beta-galactosidase. A strategy combining library screening with PCR analysis of positive clones led to the identification of a clone encoding 6 additional NH2-terminal amino acids, including a Met, which, by comparison with known PEPCK amino acid sequences, is likely to be the translation initiation site.

Three beta-tubulin cDNAs from the parasitic nematode Haemonchus contortus.

Experimental evidence indicates that tubulin is the site of action of the anthelmintic benzimidazoles. Furthermore, certain residues of beta-tubulin seem to be critical for this mechanism. Although the benzimidazoles selectively affect nematode vs. mammalian beta-tubulin, the molecular basis for this differential action is not known. To enhance our understanding of this phenomenon, and to provide the basis for investigating benzimidazole resistance in parasitic nematodes, we undertook the cloning of beta-tubulin cDNAs from the ruminant parasite, Haemonchus contortus. We have cloned and sequenced three beta-tubulin cDNAs from this organism, beta 12-16, beta 12-164, and beta 8-9. The first 2 differ at only 23 nucleotides, which give rise to 4 amino acid changes. beta 8-9 represents a different isotype class from the other two, since it differs extensively in the carboxyterminus. By comparing the sequences of these and other nematode beta-tubulins with mammalian beta-tubulins, several regions of consistent difference can be recognized; the functional significance of these regional differences has not been defined. Sequences very similar or identical to beta 8-9 and beta 12-16 are present in both benzimidazole-sensitive and benzimidazole-resistant populations of H. contortus. However, it appears that drug-resistant organisms may differ in the presence of a gene product which is closely related to beta 8-9.

Cloning of a cDNA encoding phosphofructokinase from Haemonchus contortus.

Phosphofructokinase (PFK), the key regulatory enzyme in glycolysis, has been cloned from the pathogenic parasitic nematode Haemonchus contortus by functional complementation in Escherichia coli. An E. coli strain deleted for both PFK loci (strain DF1020) was transformed with plasmid DNA from a lambda ZAP II H. contortus cDNA library. Two out of 3 x 10(7) transformants were able to grow on minimal medium with mannitol as the sole carbon source. A plasmid, pPFK, containing a 2.7-kb insert, was isolated from one of these transformants and conferred on DF1020 the ability to grow on mannitol (the PFK phenotype). The complemented cells contain PFK enzyme activity, absent in the E. coli mutant, at levels considerably higher than in wild type E. coli. Sequence analysis of the 2.7-kb insert shows an open reading frame that predicts a 789-amino acid protein that has approximately 70% similarity to mammalian PFKs. The amino acid sequence around asp182, thought to be the catalytic site, is completely conserved from nematodes to mammals.

DNA sequence recognition by the antitumor antibiotic CC-1065 and analogs of CC-1065.

The DNA base pair preferences of the antitumor antibiotic CC-1065 and two analogs of CC-1065 were studied by following the rate of covalent bond formation (N-3 adenine adduct) with DNA oligomers containing the 5'NNTTA* and 5'NNAAA* sequences (N = nucleotide, A* = alkylated adenine). The rate of adduct formation of CC-1065 is greatly affected by DNA base changes at the fourth and fifth positions of the bonding site for the 5'NNAAA sequences, but not the 5'NNTTA sequences. However, an analog of CC-1065 containing the same alkylating moiety as CC-1065, but not the third fused ring system or additional methylene and oxygen substituents, shows similar rates of adduct formation for all sequences. A second analog of CC-1065 containing three fused ring systems, but not the methylene and oxygen substituents of CC-1065, shows rates of adduct formation with the same sequence dependence as CC-1065, but does not distinguish between the sequences to the degree shown by CC-1065. Adduct formation of CC-1065, but not the analogs, competes with a reversibly bound species. Thymine bases to the 3' side of a potentially reactive adenine or a cytosine base at the fifth position from the bonding adenine create reversible binding sites which decrease the rate of adduct formation of CC-1065. The sequence 5'GCGAATT binds CC-1065 only reversibly. This sequence can compete for CC-1065 with covalent bonding sequences if the sites are located in different oligomers, or if the sites are located (overlapped or not overlapped) in the same oligomer. The results of these competitive binding experiments suggest that the transfer of CC-1065 from the reversible binding site to the covalent bonding site with both sites located on a single DNA duplex, not overlapped, occurs through an equilibrium of CC-1065 in solution, not by migration of CC-1065 in the minor groove.

Cloning and sequence analysis of the gene encoding invertase from the yeast Schwanniomyces occidentalis.

The gene encoding invertase (INV) has been cloned from Schwanniomyces occidentalis. The enzyme consists of 533 amino acids, 8 potential glycosylation sites and has a 45% identity with the invertase from Saccharomyces cerevisiae. The proenzyme has a 22 amino acid signal sequence that has a high alpha-helical transmembrane potential which differs significantly from that predicted for the Saccharomyces cerevisiae enzyme.