Peritubular capillary basement membrane reduplication in allografts and native kidney disease: a clinicopathologic study of 278 consecutive renal specimens

BACKGROUND

An association has been found between transplant glomerulopathy (TG) and reduplication of peritubular capillary basement membranes (PTCR). Although such an association is of practical and theoretical importance, only one prospective study has tried to confirm it.

METHODS

We examined 278 consecutive renal specimens (from 135 transplants and 143 native kidneys) for ultrastructural evidence of PTCR. In addition to renal allografts with TG, we also examined grafts with acute rejection, recurrent glomerulonephritis, chronic allograft nephropathy and stable grafts ("protocol biopsies"). Native kidney specimens included a wide range of glomerulopathies as well as cases of thrombotic microangiopathy, malignant hypertension, acute interstitial nephritis, and acute tubular necrosis.

RESULTS

We found PTCR in 14 of 15 cases of TG, in 7 transplant biopsy specimens without TG, and in 13 of 143 native kidney biopsy specimens. These 13 included cases of malignant hypertension, thrombotic microangiopathy, lupus nephritis, Henoch-Schonlein nephritis, crescentic glomerulonephritis, and cocaine-related acute renal failure. Mild PTCR in allografts without TG did not predict renal failure or significant proteinuria after follow-up periods of between 3 months and 1 year.

CONCLUSIONS

We conclude that in transplants, there is a strong association between well-developed PTCR and TG, while the significance of mild PTCR and its predictive value in the absence of TG is unclear. PTCR also occurs in certain native kidney diseases, though the association is not as strong as that for TG. We suggest that repeated endothelial injury, including immunologic injury, may be the cause of this lesion both in allografts and native kidneys.

Left-sided multifractality in a binary random multiplicative cascade

In this paper we study a binary random multiplicative cascade. Specifically, the cascade is used to produce and study left-sided multifractal random measures. Extensive numerical simulations of the random cascade process were undertaken and f(alpha) spectra obtained and compared with the analytical results. We believe that this model and approach can serve as a simple and fundamental tool in the analysis and understanding of physical systems possessing an underlying multiplicative structure.

Evaluation of predictive factors for neurocognitive dysfunction in patients with inactive systemic lupus erythematosus

OBJECTIVE

To determine predictive factors associated with the cognitive dysfunction in patients with inactive systemic lupus erythematosus (SLE).

METHODS

Consecutive patients followed at the Lupus Clinic with inactive SLE (SLE Disease Activity Index, SLEDAI, = 0) underwent a battery of neuropsychological tests; Beck Depression Inventory and psychiatric assessment were also performed. Neurocognitive dysfunction was defined as 3 abnormal scores. Data were analyzed using chi-square tests, ANOVA tests, and logistic regression.

RESULTS

Twenty-five of the 58 patients with SLE (43%) versus 9 of 47 healthy controls (19%) demonstrated neurocognitive dysfunction (p < 0.01). Neurocognitive dysfunction was not associated with depression or a psychiatric diagnosis, use of steroids, or previous or current evidence for fibromyalgia. SLEDAI > 10 at first presentation to the Lupus Clinic and previous vasculitis were associated with neurocognitive dysfunction, but previous central nervous system disease, renal disease, renal damage, or atherosclerotic complications were not. Neurophysiologic studies at the time of the assessment were not predictive of neurocognitive dysfunction.

CONCLUSION

Patients with inactive SLE demonstrate neurocognitive dysfunction. This is associated with more disease activity at presentation, but is not associated with specific organ involvement or organ damage.

Quantitation of allograft fibrosis and chronic allograft nephropathy

Despite improvements in the prevention and treatment of acute renal allograft rejection, the long-term survival of renal transplants has not increased. Immunologic and non-immunologic factors contribute to the gradual deterioration of graft function and to the histologic lesion characterized by vascular and interstitial fibrosis ('chronic rejection'). Quantitation of this process has been attempted using various invasive and non-invasive methods. These methods, performed at different times post-transplant, are reviewed in this article. In particular, pathology scoring systems and the potential of using computerized image analysis of biopsy material are discussed.

Peritrophins of adult dipteran ectoparasites and their evaluation as vaccine antigens

Several peritrophins of larvae of Lucilia cuprina (sheep blowfly) have demonstrated potential as vaccine antigens, and some have been characterised and cloned. These proteins are tightly associated with the peritrophic matrix, a chitinous tube or sac lining the lumen of the gut of most insects. The peritrophins require strong denaturants for their removal from peritrophic matrix. We now report the preliminary characterisation of peritrophins of the adult stage of L. cuprina and Haematobia irritans exigua (buffalo fly). Similar SDS-PAGE profiles were obtained for proteins extracted in SDS or urea from isolated adult peritrophic matrices of both species. Radioiodination of urea-extracted peritrophins improved sensitivity, indicating numerous proteins of 15-75 kDa. Direct radioiodination of L. cuprina peritrophic matrix preferentially labelled high molecular weight complexes and proteins of 80-90 kDa. Two-dimensional gel analyses of a urea extract of adult L. cuprina peritrophic matrix revealed that most proteins were moderately acidic. Antibodies produced against SDS-extracted peritrophins, or against sonicated peritrophic matrices of these two flies were crossreactive. The sera also appeared to recognise SDS-extracted components of Triton X-100 treated and washed adult peritrophic matrix of the mosquito, Aedes vigilax (Skause). This profile altered as the peritrophic matrix matured. In concordance with extracts from the adult L. cuprina and H.i. exigua peritrophic matrices, proteins in the 50-75 kDa region were immunodominant. The vaccine potential of the peritrophins of these Diptera were examined following vaccination of cattle and rabbits with adult H.i. exigua or L. cuprina peritrophins. When the adult life stages of H.i. exigua or two mosquitoes, A. vigilax and A. aegypti (Linnaeus), were fed on the sera or blood of vaccinated hosts, there were no detrimental effects to any life cycle stages of these Diptera.

Molecular cloning and expression in Escherichia coli of an aquaporin-like gene from adult buffalo fly (Haematobia irritans exigua)

A gene fragment encoding a putative member of the aquaporin gene family was amplified using cDNA prepared from unfed adult buffalo fly poly(A)+ RNA and degenerate PCR primers designed from highly conserved regions of amino acids found in all members of the aquaporin gene family. This PCR product was labelled with digoxigenin-dUTP and used as a probe to screen a lambdagt-11 cDNA library constructed from unfed adult buffalo fly. One positively hybridizing clone (AqpBF1), contained an insert of 1878 bp, and DNA sequence analysis revealed an open reading frame of 753 bp encoding a polypeptide of predicted Mr = 26 163 Da. Comparison of the AqpBF1 deduced protein sequence with the GenBank database revealed significant homology to many aquaporin genes, including 72% identity with a partial DNA sequence encoding a member (DRIP) of the MIP protein family isolated from Drosophila melanogaster. The most closely related, full-length, GenBank sequence was an aquaporin gene isolated from the digestive tract of the sap-sucking insect Cicadella viridis, which was 53% identical to the buffalo fly AqpBF1 protein sequence. The full-length coding sequence of AqpBF1 was cloned into the (His)6-fusion vector, pQE10, and the recombinant protein was expressed in Escherichia coli following induction by IPTG. The recombinant (His)6-fusion protein was localized predominantly in the membrane fraction of E. coli. The protein was solubilized from E. coli membranes with n-octyl beta-D-glucopyranoside and purified by affinity chromatography on a Ni++-sepharose column in the presence of detergent.

Effect of increasing baseline immunosuppression on the prevalence of clinical and subclinical rejection: a pilot study

This group has reported that treatment of subclinical rejection in the first 3 mo posttransplant with corticosteroids decreases late clinical rejections and improves graft function at 2 yr in renal transplant recipients. The current study was performed to determine whether an increase in baseline immunosuppression would decrease the prevalence of early subclinical rejections, as well as the incidence of early and late clinical rejections. Patients received mycophenolate mofetil (MMF) and Neoral cyclosporin A (CsA) posttransplant (n = 29), of which 17 underwent protocol biopsies at months 1, 2, 3, and 6 (Neoral + MMF Protocol Biopsy [Bx]), while 12 declined protocol biopsies (Neoral + MMF Control). These individuals were compared with 72 historical control patients treated with Sandimmune CsA and Imuran, of which 36 had undergone protocol biopsies at months 1, 2, 3, and 6 (Sandimmune + Azathioprine [AZA] Protocol Bx), and 36 had a protocol biopsy at month 6 (Sandimmune + AZA Control). Baseline immunosuppression with Neoral + MMF decreased the incidence of early clinical rejections (0 to 3 mo) and cumulative corticosteroid exposure, but had no impact on the prevalence of early subclinical rejection. Moreover, to maximally decrease the risk of developing late clinical rejections (months 7 to 12) in Neoral + MMF patients required that protocol biopsies be done and that subclinical rejection be treated. The paradoxical finding of recent clinical trials that a reduction in acute clinical rejection has not improved long-term graft outcome may be explained in part by the failure to control subclinical rejection.

Clinical rejection is distinguished from subclinical rejection by increased infiltration by a population of activated macrophages

It has been reported previously that one-third of protocol renal biopsies in asymptomatic, biochemically stable renal transplant recipients in the first 6 mo show unsuspected subclinical graft rejection (both infiltrate and tubulitis) and that subclinical rejection is a risk factor for chronic renal dysfunction. This study was performed to determine whether differences in phenotype or activation status of graft-infiltrating cells underlie these different manifestations of acute rejection. Biopsies with normal histology (n = 10), subclinical rejection (n = 13), and clinical rejection (n = 9) were studied using immunohistochemistry and computerized image analysis. Subclinical and clinical rejections had similar histologic Banff scores. Univariate analysis showed a trend for a higher infiltration with CD8+ (P = 0.053) and CD68+(P = 0.06) cells in clinical rejection. Of the activation markers studied (CD25, perforin, tumor necrosis factor-alpha), only allograft inflammatory factor-1+-activated macrophages were significantly (P = 0.014) increased in the infiltrate of clinical rejection biopsies. These data suggest that activated macrophages or their products are responsible for acute renal dysfunction associated with clinical rejection episodes.

Caring and curing revisited: student nurses' perceptions of nurses' and physicians' ethical stances

As a result of a research study involving nursing students, we have discovered some interesting patterns in the way that nursing students perceive physicians' ethical stances in comparison to their perceptions of their own profession's ethical stances. Some of the findings of this study confirm what writers in the literature have pointed out regarding how the nursing profession defines and perceives itself with reference to the medical profession. As a result of our findings, it may be useful for nursing programmes to revise and re-think the ethics of their profession vis-à-vis that of doctors.

Immune-activation gene expression in clinically stable renal allograft biopsies: molecular evidence for subclinical rejection

BACKGROUND

A significant percentage of biopsies from stable, well-functioning renal allografts have histologic findings consistent with acute rejection or borderline rejection. The implication of this finding is not yet fully understood. We analyzed immune-activation gene transcripts in stable protocol biopsies to determine the extent of immunologic activity of graft-infiltrating cells in this setting. Histologic classification of the biopsies was based on the Banff criteria. To emphasize that the tissue samples were procured from grafts with no clinical evidence of impaired function, we interjected the term "subclinical" into the Banff terminology. This produced three histologic categories: normal, borderline subclinical rejection, and acute subclinical rejection.

METHODS

We used competitive template polymerase chain reaction techniques to quantify transcript amounts for the constant region of the T-cell receptor beta chain; the cytokines, tumor necrosis factor alpha, interleukin (IL)-1beta, transforming growth factor beta, interferon gamma, IL-2, IL-4, IL-10, and IL-15; and the cytotoxic T lymphocyte effector molecules, granzyme B, perforin, and Fas ligand.

RESULTS

We found that histologically normal biopsies were typically devoid of gene transcripts or had very low amounts. Conversely, biopsies with acute subclinical rejection by histologic examination had heightened amounts of transcripts for many of the genes assayed. Borderline subclinical rejection samples showed an intermediate amount of expression.

CONCLUSIONS

These results demonstrate that histologic features of rejection are often accompanied by enhanced expression of pro-inflammatory gene transcripts, despite the absence of clinically overt graft dysfunction. As this state of subclinical rejection could prove detrimental to long-term graft function, a role for surveillance biopsies of stable grafts with intent to treat subclinical rejection should be considered.

Protocol biopsies in renal transplantation: research tool or clinically useful?

Early protocol biopsies of stable, well functioning renal allografts reveal a high prevalence of clinically unsuspected acute and chronic pathology. It is becoming increasingly apparent that these histopathological findings are both pathogenic and predictive of long-term allograft outcome. Therefore, protocol biopsies may be required for optimal post-transplant surveillance until non-invasive methods to detect allograft inflammation are developed.

Beneficial effects of treatment of early subclinical rejection: a randomized study

The prevalence of subclinical rejection, by the Banff criteria, is approximately 30% in the first 3 mo in renal transplant recipients. A randomized study was performed to determine whether the treatment of subclinical rejection with corticosteroids was associated with improved outcomes in these patients. Seventy-two patients, stratified by donor source, were randomized to biopsies at 1, 2, 3, 6, and 12 mo (Biopsy group), or to 6- and 12-mo biopsies only (Control group). Patients were analyzed by "intent to treat" and were followed for a minimum of 2 yr. Patients in the Biopsy arm of the study had a significant decrease in early (months 2 and 3) and late (months 7 to 12) acute rejection episodes, a reduced chronic tubulointerstitial score at 6 mo, and a lower serum creatinine at 24 mo than did patients in the Control arm. There was a trend toward an increase in infectious morbidity, but no increase in mortality, in the patients randomized to the Biopsy group. The results of this study suggest that early protocol biopsies and the treatment of subclinical rejection with corticosteroids may lead to better histologic and functional outcomes in renal transplant recipients.

Clinical and in situ cellular responses to Haemophilus ducreyi in the presence or absence of HIV infection

We aimed to determine if the clinical and histological features of chancroid are altered by HIV infection. Male patients presenting to the Nairobi special treatment clinic with a clinical diagnosis of chancroid were eligible for the study. A detailed history, physical examination, swabs for Haemophilus ducreyi culture and blood for HIV serology, syphilis serology and CD4 counts were obtained from all patients. Punch biopsies from an ulcer were obtained from 10 patients and either fixed in 10% formalin or snap frozen in Optimum Cutting Temperature (OCT) medium compound at -70 degrees C. Patients were treated with erythromycin and followed for 3 weeks. Chi-square and Student's t-test were used to determine if the clinical and laboratory features of chancroid differed between HIV-seropositive and seronegative individuals. Cox regression survival analysis was used to determine if HIV infection altered cure rates of chancroid at 21 days. Immunohistochemical staining was performed using lymphocytic and macrophage markers and tissue sections were analysed by 2 pathologists in a blinded manner. Between February and November 1994, 109 HIV-seropositive and 211 HIV-seronegative individuals were enrolled in the study. HIV patients had ulcers of longer duration than HIV-seronegative patients (P=0.03). Although cure rates were similar at 3 weeks, HIV patients had lower cure rates at 1 week (23% v 54%, P=0.002). A dense interstitial and perivascular inflammatory infiltrate extending from the reticular to deep dermis was present in all biopsies. This consisted of equal amounts of CD4 and CD8 T-lymphocytes as well as macrophages. The histological and immunohistochemical picture was identical for HIV-positive and negative patients. HIV infection slows the healing rates of chancroid ulcers despite appropriate antibiotic therapy. This clinical difference cannot be attributed to an altered histopathological response to HIV infection. Additional studies are needed to elucidate the mechanisms responsible for this finding.

Identification of clinical and histopathologic risk factors for diminished renal function 2 years posttransplant

The aim of this study was to identify early clinical and pathologic variates that independently predict diminished renal allograft function at 24 mo posttransplant. A clinical pathologic data base was prospectively derived from 71 patients in whom protocol renal biopsies were performed at 1, 2, 3, 6, and 12 mo posttransplant. The major end point was the 24-mo serum creatinine. Variates correlating independently (r2 = 0.67) with the 24-mo serum creatinine were the chronic biopsy scores (months 3 and 6), late rejections (months 4 to 6), cyclosporin A (CsA) levels (months 1 to 2), and delayed graft function. The adjusted odds ratio (OR) and 95% confidence interval (CI) for having a serum creatinine > or = 130 mumol/L at 24 mo increased for every year the donor age increased (OR = 1.07; 95% CI, 1.02 to 1.13; range, 9 to 55) or for each late rejection episode (OR = 5.9; 95% CI, 1.7 to 20.1), whereas a mean CsA level > 300 micrograms/L from months 1 to 3 was protective (OR = 0.07; 95% CI, 0.01 to 0.43). Variates correlating independently (r2 = 0.53) with the change in serum creatinine from 6 to 24 mo (delta Cr6-24) were the chronic biopsy scores at months 3 and 6. The adjusted OR of the delta Cr6-24 rising > or = +20 mumol/L increased for every year the donor age increased (OR = 1.09; 95% CI, 1.02 to 1.16; range 9 to 56) or when the 6-mo chronic biopsy score was > or = 2 (OR = 6.6; 95% CI, 1.2 to 36.4). An estimate of the relative risk for diminished renal function at 2 yr can be assigned within 6 mo of transplant based on chronic pathology, late acute rejections, CsA levels, and donor age.

Fibromyalgia is a major contributor to quality of life in lupus

OBJECTIVE; To determine whether individual variables of the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) and Systemic Lupus International Coordinating Committee/American College of Rheumatology (SLICC/ACR) Damage Index were associated with any of the domains of the Short Form 36 (SF-36) quality of life measure, and to assess the contribution of fibromyalgia (FM) to the quality of life measure.

METHODS

Patients with systemic lupus erythematosus (SLE) seen between December 1994 and May 1995 completed SF-36 questionnaires at the time of their clinical evaluations at the Lupus Clinic. Disease activity was measured by SLEDAI, damage was assessed by the SLICC/ACR Damage Index, and FM was diagnosed in the presence of widespread pain and > or = 11 of 18 FM tender points. The components of SLEDAI and the Damage Index were compared to the domains of the SF-36 using Pearson correlation coefficients. A t test was used to compare the variables in patients with and without FM.

RESULTS

One hundred nineteen patients with SLE participated in the study. Presence of FM, which occurred in 21% of the patients, was not related to either the overall scores or any of the components of SLEDAI or Damage Index, but was highly correlated with all 8 domains of the SF-36. The correlations ranged from -0.26 to -0.43, with associated p values of 0.007 to 0.0001.

CONCLUSION

In a cross sectional study of patients with SLE at one point in time the SF-36 reflected the presence of FM rather than disease activity or damage.

Hormone replacement therapy in systemic lupus erythematosus

OBJECTIVE

To test whether hormone replacement therapy (HRT) causes an increase in lupus flares.

METHODS

Sixteen postmenopausal patients with systemic lupus erythematosus (SLE) who had been taking HRT for at least 12 months were included in the study. Thirty-two controls were matched to patients for age at start of hormone therapy and calendar year of followup. The incidence of disease flare was defined as any increase in Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) over 12 months from baseline in these 2 groups; incidence of flare was compared by McNemar's test or Mantel-Haenszel test.

RESULTS

Control patients were older at diagnosis (38.8 vs 30.5 yrs) and at presentation to clinic (41 vs 30 yrs). HRT patients had longer disease duration (17.9 vs 5.6 yrs). SLEDAI at presentation was similar in both groups. There was no statistically significant difference in the rates of flares in both groups.

CONCLUSION

The use of HRT in postmenopausal women with SLE does not appear to increase the rate of lupus flares over a one year followup.

Pattern of neuropsychologic dysfunction in inactive systemic lupus erythematosus

The pattern of neuropsychological dysfunction in patients with inactive systemic lupus erythematosus (SLE) was examined. Fifty-eight subjects with inactive SLE and 47 healthy controls were administered a standardized neuropsychological test battery. Summary scores reflecting 18 different cognitive processes were derived. Subjects were designated cognitively impaired if three or more summary scores differed significantly from premorbid estimates of cognitive functioning. Cognitive impairment was identified in 43% of subjects with inactive SLE and 19% of healthy controls. Subjects with inactive SLE, as a group, performed significantly worse than healthy controls on measures of auditory verbal memory, visual spatial memory, psychomotor speed, and motor functioning. A significantly greater proportion of subjects with inactive SLE than healthy controls was impaired only on a measure of visual spatial memory. Cognitive impairment in subjects with inactive SLE was associated with increasing age. There were no associations between cognitive impairment and current depressive symptoms or current corticosteroid use. These findings suggest that cognitive dysfunction occurs frequently in inactive SLE. The variability of performance of subjects with inactive SLE is consistent with the heterogeneity of CNS involvement in the disease.

Expression of angiotensin-converting enzyme-related carboxydipeptidases in the larvae of four species of fly

HieACE, a soluble 70 kDa protein related to the angiotensin-converting enzyme (ACE) has recently been identified, characterized and cloned from the adult buffalo fly (Haematobia irritans exigua). HieACE is enzymatically similar to the mammalian ACEs and its predicted amino acid sequence has 42% identity with the mammalian testicular ACEs. In adult H.i. exigua, HieACE expression is restricted to the compound ganglion and posterior midgut, and the maturing male reproductive system. Western blot analysis was used to investigate the expression of HieACE and its homologues in the larvae of H.i. exigua, Drosophila melanogaster, the sheep blowfly (Lucilia cuprina), the Old World screwworm fly (Chrysomya bezziana) and a secondary strike fly, Chrysomya rufifacies. Dipteran ACE homologues of 65-70 kDa were detected in all the larval instars investigated. Most of the immunoreactive proteins were concentrated in the soluble fraction. The first and second larval instars of L. cuprina and C. bezziana appeared to express two ACE homologues. These larvae were also found to secrete (or excrete) the ACE homologue in larval cultures. The presence of ACE-like enzymes in these larvae was confirmed by the measurement of carboxydipeptidase activity that was inhibited by the specific ACE inhibitor, captopril. The tissue distributions of the ACE homologues in the third instar larvae of H.i. exigua and L. cuprina were examined. As in adult H.i. exigua, HieACE was detected in the larval ganglion, but in contrast to the restricted distribution in the adult stage midgut, HieACE was found throughout the digestive system, and in the salivary glands of H.i. exigua larvae. The expression pattern in the gut of L. cuprina larvae was similar despite the differences in diet and habitat. The most striking difference from the adult stage H.i. exigua was the expression of HieACE and its L. cuprina homologues in the hindgut and Malpighian tubules of these larvae. These results suggest that the role(s) played by the dipteran ACE-like enzymes differ between the adult and larval stages.