Ocular Pathology in Light Chain Deposition Disease

Light-chain deposition disease (LCDD), a rare form of monoclonal gammopathy, is characterized by deposits of amorphous light-chain material, mainly in the kidneys but also in various other organs. Here we present the first report of a light-, electron microscopic and immunohistochemical study of the globes of a patient suffering from LCDD secondary to multiple myeloma. Massive deposits of kappa light chains similar to those typically present in the kidneys were found beneath the basement membrane of the ciliary pigment epithelium, on vessels of the ciliary body, within the collagenous zones of Bruch's membrane, and in the innermost part of the choroid. The choriocapillaris in the macular area was partly obstructed by these deposits, and an exudative retinal detachment was present. Whether this detachment was the consequence of disturbed circulation of the choriocapillaris remains speculative.

The different ways to obtain digital images of urine microscopy findings: Their advantages and limitations

We describe three ways to take digital images of urine sediment findings. Way 1 encompasses a digital camera permanently mounted on the microscope and connected with a computer equipped with a proprietary software to acquire, process and store the images. Way 2 is based on the use of inexpensive compact digital cameras, held by hands - or mounted on a tripod - close to one eyepiece of the microscope. Way 3 is based on the use of smartphones, held by hands close to one eyepiece of the microscope or connected to the microscope by an adapter. The procedures, advantages and limitations of each way are reported.

Atypical/malignant urothelial cells in routine urinary sediment: worth knowing and reporting

BACKGROUND

Urinary cytology (Ucytol), which is performed in pathology laboratories on fixed and stained samples, represents the gold standard for the identification of atypical/malignant urothelial cells (A/MUC) due to urothelial carcinoma. In this paper we describe three patients in whom A/MUC, due to a bladder carcinoma, were identified with conventional urine sediment (Used) examination on unfixed and unstained samples.

METHODS

Included are urine samples prepared with conventional and standardized techniques as currently used in general clinical laboratories. Samples were examined with phase contrast microscopy. A/MUC were identified according to the criteria currently used for Ucytol.

RESULTS

A/MUC (i.e., cells with unusual and pleomorphic size and shape, increased nuclear/cytoplasmic ratio, increased number of nuclei, irregular nuclear borders and irregular chromatin patterns, either isolated or in clusters) were identified in the urine of three patients, all of whom were found to have bladder carcinoma by cystoscopy.

CONCLUSIONS

At variance with the common and widespread view, A/MUC can also be identified with conventional Used examination, even though Ucytol still represents the gold standard method.

[The classics of Italian nephrology: ''Hormones in renal physiology and renal pathology'' by Silvano Lamperi (1922-2008) e Rodolfo Cheli (1928-1997)]

This monograph, published in 1955, describes the effects that cortisone, desoxycorticosterone, adrenocorticotropic hormone, growth hormone, and testosterone have on renal function, renal metabolism and renal enzymatic activity. The two main chapters of the book describe the experimental results obtained by the authors with the administration of the above-mentioned hormones to rats in terms of renal morphology and function both in basal conditions and after the injection of nephroptoxic substances. Interestingly, the effects on function were evaluated by the measurement of the consumption of oxygen by kidney sections incubated with hormones in different experimental conditions. The results demonstrated that both cortisone and adrenocorticosterone could have a protective effect on kidney damage, which could be used for clinical purposes. Today, the monograph by Lamperi and Cheli is interesting because it shows that advanced experimental research was carried out in Italy in the early 1950s. Moreover, it represents an early attempt to the application of experimental results to the clinic.

[The Classics of Italian Nephrology: ''The physiopathological basis for the nosography and the classification of bilateral kidney diseases'' by Pio Bastai (1888-1975) and Massimo Crepet (1911-1994)]

The paper ''I fondamenti fisiopatologici per la nosografia e la classificazione delle malattie renali bilaterali'' (The physiopathological basis for the nosography and the classification of bilateral kidney diseases'') by Pio Bastai (1888-1975) and Massimo Crepet (1911-1994) was presented at the 54th Congress of the Italian Society of Internal Medicine, which was held in October 1953 in Rome. In the report, the authors proposed their own classification of renal diseases based on a ''physopathological'' criterion and different from the classifications proposed by other authors of the period. According to Bastai and Crepet, renal diseases could be classified into arteriolopathies (either acute or chronic), capillary diseases (glomerulonephritides, including inflammatory and noninflammatory forms), renal diseases due to circulatory failure, nephropathies due to toxic substances, interstitial nephropathies, and idiopathic nephropathies. Of particular interest today is the part of the paper on the nosography of the so-called ''genuine glomerulonephrosis'' which, at variance with the view of the leading clinicians at the time, was placed among the inflammatory glomerulonephritides. In addition, the authors expressed their uncertainty about the existence of primary chronic interstitial nephropathies. Today, the paper by Bastai and Crepet shows how difficult it was to propose a classification of renal diseases in a period when the use of renal biopsy was still in its infancy.

[The classics of Italian nephrology. 'Functional semiology of the kidney' by Giovanni Gigli (1913-1988) and Sergio Giovannetti (1924-2000)]

The monograph Semeiologia funzionale del rene (Functional semiology of the kidney) by Giovanni Gigli (1913-1988) and Sergio Giovanetti (1924-2000), published in 1953, was the first systematic survey on the subject to appear in Italy. Besides the classical renal function tests (urinalysis, BUN measurement, urea clearance), the book recounts the many new techniques that were introduced into clinical practice in that period as a result of the great advances in the field of renal physiology (e.g., glomerular filtration rate, renal plasma and blood flow, tubular water reabsorption, maximum tubular excretion and reabsorption capacity, filtration fraction). In addition, it describes the utility and pitfalls of such tests in a wide spectrum of kidney diseases, but especially in different types of glomerulonephritis, of which the two authors had collected a personal cohort of 48 patients. Today, the monograph by Gigli and Giovannetti shows the difficulties and uncertainties encountered in the evaluation of kidney diseases in a period in which renal biopsy was yet to become the widely used technique it is today.

[The classics of Italian nephrology: the monograph "La nefropatia diabetica" (Diabetic nephropathy) by Luigi Scapellato (1918-1998)]

This monograph, published in 1953, describes the findings observed by the author in a cohort of patients affected by diabetes mellitus and renal disease. From a pathological standpoint, the typical renal lesion is represented by ''nodular intercapillary glomerulosclerosis'', which is present in 8 out of 20 patients at postmortem. Marked proteinuria and edema are the most typical clinical features. Urinary sediment examination is the only test allowing to differentiate diabetic nephropathy from other glomerular diseases. In the initial phases, the glomerular filtration rate is increased rather than reduced. The evolution is almost invariably towards end-stage renal disease, and a hypoglucidic diet and insulin are the only therapeutic modalities available. Today this work shows us, on the one hand, how many uncertainties still existed about diabetic nephropathy 17 years after its first description by Kimmelstiel and Wilson in 1936. On the other hand, it shows how much relevant and still valid information was already known at the time. Luigi Scapellato, who is almost completely forgotten today, began his career at the Clinica Medica of the University of Rome under the guidance of Cesare Frugoni (1881-1978). In 1959, he moved to Syracuse (Sicily) to work as director of the internal medicine unit of the ''Umberto I'' Hospital. In April 1957 he was among the 13 founders of the Italian Society of Nephrology.

[Historical Archives of Italian Nephrology. Gabriele Monasterio (1903-1972) and the School of Pisa]

Gabriele Monasterio (1903-1972), a clinician with numerous medical interests, contributed remarkably to the development of the Italian nephrology of his time. His main scientific contributions were: - Investigation of the causes of normoglycaemic glycosuria. Of this condition he collected, from 1939 on, a large series of patients whom he also investigated - for the first time in the world - with renal biopsy and - thanks to a collaboration with Jean Oliver - the microdissection of the nephron. - Introduction, in the early 1960s, of a low protein diet for the patients with chronic renal failure. This, thanks to the stud-ies published by Monasterio co-workers Quirino Maggiore and Sergio Giovannetti, was largely used in Italy and abroad. - Classification of the nephropathies. This was described in the monograph Le Nefropatie Mediche (1954 and 1970), which had a large impact and today represents a classic of the Italian nephrological literature. Monasterio served remarkably the Italian Society of Nephrology: in 1957 as a member of the founding committee; from 1959 to 1962 and from 1964 to 1968 as President; in 1958, 1962, and 1964 as organizer of the National Congress; from 1962 to his death as the Editor-in-Chief of the official journal of the Society, Minerva Nefrologica. Finally, Monasterio was also a member of the first council of the International Society of Nephrology.

Risk factors associated to kidney stones in primary hyperparathyroidism

Nephrolithiasis is the most important clinical manifestation of primary hyperparathyroidism (PHPT), although nowadays this disorder is often asymptomatic. Clinical or biochemical differences between PHPT patients with and without nephrolithiasis have not been clearly identified in most of the previous studies. The aim of the study was to investigate clinical and biochemical parameters in kidney stone former (SF) and non-stone former (NSF) patients with PHPT in order to identify potential risk factors. Serum and plasma samples from 55 consecutive patients (43 females, 12 males) with PHPT were collected after overnight fasting; 24-h urine collection and a fresh sample of urine for sediment analysis were obtained from all patients. Clinical data were recorded in all. Out of 55 patients, 22 had kidney stones, which were symptomatic in 73%. SFs showed circulating PTH, total and ionized calcium, 1,25 dihydroxyvitamin D3, urinary calcium excretion and 24-h urine oxalate levels significantly higher than NSFs. Hypercalciuria was often concomitant with massive quantities of calcium oxalate crystals in urine sediment. Hypercalciuria and relatively high oxaluria were associated with stone formation with an odds ratio (OR) of 4.0 and 7.0, respectively, which rose to 33.5 when they coexisted. Hypomagnesuria and hypocitraturia were common in at least one third of all PHPT patients, but they were not associated to an increased OR. As expected, they were positively correlated with urine calcium excretion, suggesting that calcium, magnesium and citrate are commonly regulated at renal level. In conclusion, hypercalciuria, higher oxalate excretion and severe PHPT are associated with kidney stones in PHPT.

[Historical Archives of Italian Nephrology: the artificial kidney commissioned in 1947 by Aminta Fieschi (1904-1991)]

Aminta Fieschi, a physician who is today remembered mainly for his contributions in the field of haematology, in the late 1940s devoted himself to the study of the treatment of uraemia. For this reason he commissioned, a manufacturer based in Milano, an artificial kidney, which was built on the design of the "rotating-drum kidney" described by Willem Kolff in 1947 in his epoch-making monograph "New Ways of Treating Uraemia". However, after using that artificial kidney in few patients Fieschi abandoned it due to dangerous cardiovascular complications, and shifted to the use of other safer techniques such as intestinal perfusion. This paper describes the main contributions of Fieschi in the field of nephrology as well as the features of artificial kidney he used, whose manufacturer has been identified and retraced after more than fifty years by the author.

[Historical archives of Italian nephrology: Introduction of the artificial kidney in Italy]

In Italy the first attempts at haemodialysis, first in vitro and animals and then in humans, were carried out in the early 1950s by the surgeons Mario Battezzati e Carlo Taddei of Genoa with an artificial kidney of their own design. During the same years several other surgeons and urologists in Padua, Milan, Turin, Florence, Modena, Rome, Naples and Palermo designed their own artificial kidneys, which were used to treat anuric patients suffering from acute renal failure. The lively interest in artificial kidneys led, in 1954, to the organisation of a symposium on the subject. This was the first symposium of its kind not only in Italy but also at European level and was characterised by a wide discussion on all aspects associated with extracorporeal dialysis. In subsequent years the use of artificial kidneys continued to develop in several of the above-mentioned Italian centres, something that in the early 1960s led to the introduction of chronic haemodialysis. This paper shows how in Italy the use of artificial kidneys was characterised by intense experimental and clinical activity as well as original approaches to the many problems associated with the use of this technique.

Role of proteinuria reduction in the progression of IgA nephropathy

Proteinuria has been shown to play a causal role in the progression towards ESRD of IgA nephropathy (IgAN). We demonstrated that steroids are effective in reducing proteinuria and preserving renal function.

AIM

to evaluate the long-term effect of steroids in IgAN patients (6th year evaluation) and better clarify the role of proteinuria reduction in slowing down the progression.

METHODS

multicenter randomized controlled trial of 86 adult IgAN patients with serum creatinine < or = 1.5 mg/ dL and moderate proteinuria. They received either supportive therapy or methylprednisolone 1-g i.v. for three days at months 1, 3, and 5, plus oral prednisone (0.5 mg/kg every other day for six months).

RESULTS

Proteinuria significantly decreased in the treated patients (from 2.0+/-0.60 g/24 h at baseline to 1.0+/-0.68 g/24 h at six months) and remained stable till the 6th year (0.67+/-0.5 g/24 h), it slightly decreased in the control group. Six-year renal survival was significantly better in the steroid than in the control group: 9 patient (20.9%) in the steroid group and 15 (34.8%) in the control group reached the primary end-point of a 50% increase in serum creatinine from baseline. Five controls and none of the steroid-treated patients started dialysis. Steroid-treated patients did not experience any major side effects during follow-up.

CONCLUSIONS

Steroids significantly reduce proteinuria and protect against renal function deterioration in IgAN patients. Early reduction of proteinuria could also be marker of a persistent reduction in its levels over time and of a better outcome in the long term.

Towards European urinalysis guidelines. Introduction of a project under European Confederation of Laboratory Medicine

Improved standardized performance is needed because urinalysis continues to be one of the most frequently requested laboratory tests. Since 1997, the European Confederation of Laboratory Medicine (ECLM) has been supporting an interdisciplinary project aiming to produce European urinalysis guidelines. More than seventy clinical chemists, microbiologists and ward-based clinicians, as well as representatives of manufacturers are taking part. These guidelines aim to improve the quality and consistency of chemical urinalysis, particle counting and bacterial culture by suggesting optimal investigative processes that could be applied in Europe. The approach is based on medical needs for urinalysis. The importance of the pre-analytical stage for total quality is stressed by detailed illustrative advice for specimen collection. Attention is also given to emerging automated technology. For cost containment reasons, both optimum (ideal) procedures and minimum analytical approaches are suggested. Since urinalysis mostly lacks genuine reference methods (primary reference measurement procedures; Level 4), a novel classification of the methods is proposed: comparison measurement procedures (Level 3), quantitative routine procedures (Level 2), and ordinal scale examinations (Level 1). Stepwise strategies are suggested to save costs, applying different rules for general and specific patient populations. New analytical quality specifications have been created. After a consultation period, the final written text will be published in full as a separate document.

The early introduction of percutaneous renal biopsy in Italy

BACKGROUND

Percutaneous renal biopsy, based on the use of an aspiration needle and the patient in the sitting position, was first described by Iversen and Brun in 1951. In 1954, Kark and Muehrcke described the use of the cutting Vim-Silverman needle on patients in the prone position, with a substantial improvement in the rate of success. The 1961 CIBA Foundation Symposium on renal biopsy marked the coming of age of this technique. During the 1950s in Italy, several individuals played a part in promoting and developing percutaneous renal biopsy. Because this pioneer work has received insufficient attention, we describe the contributions of Italians to the early introduction of this technique.

METHODS

The Italian and international literature about percutaneous renal biopsy of the period 1951 through 1965 was reviewed. In addition, structured interviews with surviving members of the Italian researchers who first used renal biopsy were conducted.

RESULTS

The first renal biopsies in Italy were performed in 1951 in Pisa by the group of Ernico Fiaschi (1913-1989). In their hands, renal biopsy became a tool to investigate the pathogenesis of renal diseases in particular, while simultaneously using the early application of immunofluorescence and electron microscopy. In 1954, Pietro Leonardi (1914-1991) and Arturo Ruol (born 1924) introduced renal biopsy in Padova; they used this technique extensively and published one of the first monographs on the subject. In 1957, Vittorio Bonomini (born 1928) introduced renal biopsy in Bologna, and in subsequent years used this technique to focus on the study of pyelonephritis.

CONCLUSIONS

Our historical research shows that Italian groups were among the first to use and develop percutaneous renal biopsy both as a clinical tool and an investigative tool. This article gives international credit to their work.

In vitro erythrophagocytosis by renal tubular cells and tubular toxicity by haemoglobin and iron

BACKGROUND

Patients with gross haematuria of glomerular origin may develop acute tubular necrosis and reversible renal failure. Erythrocytes within the cytoplasm of proximal tubular epithelial cells (PTECs) can be seen on examination of renal biopsies from these patients. It is possible, therefore, that the tubular damage is a result of cytotoxic breakdown products released during erythrocyte degradation.

METHODS

To test this hypothesis, we evaluated (i) by transmission electron microscopy, the capability of a PTEC line to phagocytose and degrade erythrocytes in vitro; and (ii) the effect on the viability of PTCEs in vitro both after erythrophagocytosis and after incubation with haemoglobin, free iron or both.

RESULTS

Electron microscopic examination of PTECs exposed to erythrocytes for 96 h showed that 22% of PTECs contained one or more erythrocyte. These were within phagolysosomes and showed varying stages of degradation, with collapse and breakdown of the cell membrane and invasion by cytoplasmic organelles (the so-called haemolytic pathway of erythrocyte degradation). Despite the phagocytosis and degradation of the erythrocytes, no cytotoxicity could be demonstrated under the experimental conditions used. However, the presence of haemoglobin, free iron or both in the culture medium was toxic to the PTECs, resulting in a significant reduction in the number of viable cells present.

CONCLUSIONS

PTECs are able to phagocytose and degrade erythrocytes, and haemoglobin and iron are toxic to proximal tubular cells in vitro.

Corticosteroids in IgA nephropathy: a randomised controlled trial

BACKGROUND

IgA nephropathy is progressive in most cases and has no established therapy. In this randomised trial, we assessed the efficacy and safety of a 6-month course of steroids in this disorder.

METHODS

Between July, 1987, and September, 1995, we enrolled 86 consecutive patients from seven renal units in Italy. Eligible patients had biopsy-proven IgA nephropathy, urine protein excretion of 1.0-3.5 g daily, and plasma creatinine concentrations of 133 micromol/L (1.5 mg/dL) or less. Patients were randomly assigned either supportive therapy alone or steroid treatment (intravenous methylprednisolone 1 g per day for 3 consecutive days at the beginning of months 1, 3, and 5, plus oral prednisone 0.5 mg/kg on alternate days for 6 months). The primary endpoint was deterioration in renal function defined as a 50% or 100% increase in plasma creatinine concentration from baseline. Analyses were by intention to treat.

FINDINGS

Nine of 43 patients in the steroid group and 14 of 43 in the control group reached the primary endpoint (a 50% increase in plasma creatinine) by year 5 of follow-up (p<0.048). Factors influencing renal survival were vascular sclerosis (relative risk for 1-point increase in score 1.53, p=0.0347), female sex (0.22, p=0.0163), and steroid therapy (0.41, p=0.0439). All 43 patients assigned steroids completed the treatment without experiencing any important side-effects.

INTERPRETATION

A 6-month course of steroid treatment protected against deterioration in renal function in IgA nephropathy with no notable adverse effects during follow-up. An increase in urinary protein excretion could be a marker indicating the need for a second course of steroid therapy.

Urinary microscopy as seen by nephrologists

Urinary microscopy is a diagnostic tool which is largely used by nephrologists. In the opinion of the authors the best results can be achieved when all the aspects concerning this test are properly taken into account. Thus, from the methodological point of view, proper patient guidance, proper urine collection and handling, adequate microscopic equipment, and knowledge of the factors which can influence the results are all necessary. All the elements of clinical importance have to be known, namely, erythrocytes (with their morphological subtypes), leukocytes, tubular cells, uroepithelial cells (both superficial and deep), lipids, casts, crystals, and microorganisms. Then, the urinary findings have to be interpreted and, whenever possible, also combined into urinary profiles (e.g., the nephritic sediment, the nephrotic sediment). This, combined with other laboratory tests, the pathologic findings, and the clinical data, allows for the definition and management of urinary tract diseases.

Glomerulonephritis associated with myasthenia gravis

In a follow-up study of 128 myasthenic patients from a neurological center in Northern Italy, three were found to have developed glomerulonephritis at variable intervals after the onset of myasthenia gravis, thymoma (two patients), and thymectomy. By renal biopsy, two patients (cases 1 and 3) were found to have membranous nephropathy; and one (case 2), pauciimmune extracapillary glomerulonephritis. At follow-up, patient 1 was persistingly nephrotic and developed renal failure, and patient 3 only had urinary abnormalities. Patient 2 developed end-stage renal disease. The review of the literature showed 10 other cases of glomerulonephritis associated with myasthenia gravis with or without thymoma and thymectomy. Therefore, it is likely that these conditions are pathogenetically linked. The role of autoantibodies, thymoma, and thymectomy in favoring glomerulonephritis in myasthenic patients is discussed.

Don't forget sickled cells in the urine when investigating a patient for haematuria

Haematuria is a well-known complication of sickle cell disease. A South African coloured patient with repeated episodes of gross haematuria is described in whom the diagnosis of sickle cell disease was suggested after the finding of sickled erythrocytes in the urine sediment. The diagnosis was then confirmed by haemoglobin electrophoresis, which revealed sickle cell trait (Hb-AS). It is concluded that sickle erythrocytes must be looked for when urine is microscopically scrutinized to determine the source of a haematuria.

IgA-associated renal diseases

IgA nephropathy and Schönlein-Henoch purpura nephritis are common renal diseases. Recent studies have provided new insights into the factors that contribute to the initiation and progression of renal injury. Approaches to therapy, although still limited and largely empirical, show some encouraging results.

Crystalluria: a neglected aspect of urinary sediment analysis

Crystalluria is a frequent finding in the routine examination of urine sediments. In most instances the precipitation of crystals of calcium oxalate, uric acid triple phosphate, calcium phosphate and amorphous phosphates or urates is caused by transient supersaturation of the urine, ingestion of foods, or by changes of urine temperature and/or pH which occur upon standing after micturition. In a minority of cases, however, crystalluria is associated with pathological conditions such as urolithiasis, acute uric acid nephropathy, ethylene glycol poisoning, hypereosinophilic syndrome. In addition, crystalluria can be due to drugs such as sulphadiazine, acyclovir, triamterene, piridoxylate, primidone, which under the influence of various factors can crystallize within the tubular lumina and cause renal damage. In all these instances the study of crystalluria is diagnostically useful and is also important to follow the course of the disease. However, a proper methodological approach is necessary. This includes the handling of freshly voided urine, the knowledge of the urinary pH, and the use of a contrast phase microscope equipped with polarizing filters.

Renal disease and patient survival in light chain deposition disease

We evaluated retrospectively the presenting clinical features, response to treatment and clinical course of 19 patients with LCDD, 11 of whom had multiple myeloma. At presentation, renal insufficiency was present in 18 patients and proteinuria in 16. Renal biopsy revealed typical LCDD in 16 patients, while in the remaining three LCDD was associated with other abnormal tissue deposits. Extrarenal signs were observed in 12 patients (63%), with the liver, heart and peripheral nerves being the most frequently involved organs. After diagnosis, 18 patients underwent therapy: 2 received steroids alone and 16 were treated with steroids and cytotoxic drugs; 7 patients also underwent plasma exchange. At the end of the first month of treatment renal function improved in 5 patients, worsened in 5 and remained unchanged in 8. All but 3 of the patients continued treatment beyond the first month: 7 patients developed end-stage renal disease, 5 an improvement and 4 a worsening in renal function. No effect on proteinuria was observed. Extrarenal symptoms developed in 4 previously unaffected patients and in 3 others they extended to more organs. Sixteen patients died: 12 during the first year of the follow-up, and 4 at 21st, 34th, 37th and 82nd month of observation. Five patients died from neoplastic cachexia, 4 from hypokinetic cardiopathy, 3 from hemorrhagic complications, 2 from pneumonia and one from unknown cause. Mean patient survival after presentation was 18.1 +/- 20.7 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Light chain deposition disease of the kidney. Morphological aspects in 24 patients

Renal biopsies and autopsy specimens of 23 patients with light chain deposition disease (LCDD) and one with only heavy chain deposits, were studied by light (LM) and electron microscopy (EM) as well as immunohistology (IH). Thirteen patients had multiple myeloma; 1 had lymphoma, and 1 chronic myeloid leukaemia with polycythaemia vera. In nine patients, no lymphoproliferative disease was identified. The LM lesions most suggestive of LCDD, nodular glomerulosclerosis (NS) and thickening and wrinkling of the tubular basement membranes (TBM), were present in only ten and 13 patients, respectively. In five of seven specimens without NS or TBM thickening by LM, EM was negative, indicating a limited value of EM in confirming the diagnosis. Renal amyloidosis was not identified, but in one patient amyloid in the heart and tongue was seen at autopsy. One patient had both granular and extensive glomerular non-amyloid fibrillary deposits. In two patients myeloma casts were identified. Twenty-one patients showed renal LC immune reactivity, 1 had both alpha heavy and lambda LC, 1 had only detectable gamma heavy chain. One biopsy was negative by IH, but had characteristic electron dense deposits. In six patients with immune reactivity to LC, no electron dense deposits could be identified by EM. This study emphasizes the spectrum of renal changes by LM and EM in LCDD, the frequent lack of consistency between deposits detected by IH and EM and the difficulty in coming to a definite diagnosis without LM, EM and IH. The results of this study and examination of the literature indicates that extensive morphological changes are more often present in kappa than in lambda LCDD.