Postexercise urinary alpha-1 acid glycoprotein is not dependent on hypoxia.

Proteinuria is a transient physiological phenomenon that occurs with a range of physical activities and during ascent to altitude. Exercise intensity appears to dictate the magnitude of postexercise proteinuria; however, evidence also indicates the possible contributions from exercise-induced hypoxemia or reoxygenation. Using an environmental hypoxic chamber, this crossover-designed study aimed to evaluate urinary alpha-1 acid glycoprotein (α1-AGP) excretion pre/postexercise performed in hypoxia (HYP) and normoxia (NOR). Sixteen individuals underwent experimental sessions in normoxia (NOR, 20.9% O2) and hypoxia (HYP, 12.0% O2). Sessions began with a 2-h priming period before completing a graded maximal exercise test (GXT) on a cycle ergometer, which was followed by continuation of exposure for an additional 2 h. Physiological responses (i.e., blood pressure, heart rate, and peripheral oxygenation), Lake Louise Scores (LLSs), and urine specimens (analyzed for albumin and α1-AGP) were collected pre- and postexercise (after 30, 60, and 120 min). Peak power output was significantly reduced in HYP (193 ± 45 W) compared with NOR (249 ± 59 W, P < 0.01). Postexercise urinary α1-AGP was greater in NOR (20.04 ± 14.84 µg·min-1) than in HYP (15.08 ± 13.46 µg·min-1), albeit the difference was not significant (P > 0.05). Changes in urinary α1-AGP from pre- to post-30 min were not related to physiological responses or performance outcomes observed during GXT in NOR or HYP. Despite profound systemic hypoxemia with maximal exercise in hypoxia, postexercise α1-AGP excretion was not elevated above the levels observed following normoxic exercise.NEW & NOTEWORTHY By superimposing hypoxic exposure and maximal exercise, we were able to investigate the impact of hypoxia on postexercise proteinuria. Urinalysis for α1-AGP (via particle-enhanced immunoturbidimetry) in specimens collected pre-/postexercise enabled the sensitive detection of altered glomerular permeability. Data indicated that exercise intensity, rather than the degree of exercise-induced hypoxemia, determines postexercise proteinuria.

Losartan Has No Effect on High Altitude Diuresis or Acute Mountain Sickness in Well-Acclimatizing Individuals.

Delamere, John P., Susie B. Bradwell, Christopher T. Lewis, Alex Clarke, and Arthur R. Bradwell. Losartan has no effect on high altitude diuresis or acute mountain sickness in well-acclimatizing individuals. High Alt Med Biol. 22:96-101, 2021. Introduction: The diuretic response that occurs on ascent to altitude is associated with suppression of aldosterone. We speculated that losartan, an angiotensin II receptor blocker, might further reduce aldosterone activity thereby enhancing the diuresis. Materials and Methods: Twenty subjects (paired for angiotensin converting enzyme genotypes [II:ID:DD] gender and age) were randomized, on a double-blind basis, to either daily losartan, 100 mg, or placebo. During 7 days of motorized ascent from 2,850 to 5,035 m, collections of 24-hour urine output were measured daily with samples taken for sodium (Na+) and potassium (K+) concentrations. In addition, measurements were made of blood gases and aldosterone concentrations. Results: During the main ascent, there were similar progressive increases in 24-hour urine volumes in placebo and losartan groups with no change in Na+ or K+ excretion. There were negative correlations between mean 24-hour urine volumes and PaO2 (r = -0.97, p < 0.03), and the diuretic response and acute mountain sickness scores at 5,053 m (r = -0.51, p < 0.03). There were no significant changes in aldosterone concentrations measured at baseline and at our high point on day 6 within or between the losartan and placebo groups. Conclusion: The high altitude diuretic response was not increased by losartan indicating aldosterone activity was suppressed in individuals on placebo who were acclimatizing well to altitude.

Effect of losartan on performance and physiological responses to exercise at high altitude (5035 m).

OBJECTIVE: Altitude-related and exercise-related elevations in blood pressure (BP) increase the likelihood of developing pulmonary hypertension and high-altitude illness during high-altitude sojourn. This study examined the antihypertensive effect and potential exercise benefit of the angiotensin II receptor antagonist losartan when taken at altitude. METHODS: Twenty participants, paired for age and ACE genotype status, completed a double-blinded, randomised study, where participants took either losartan (100 mg/day) or placebo for 21 days prior to arrival at 5035 m (Whymper Hut, Mt Chimborazo, Ecuador). Participants completed a maximal exercise test on a supine cycle ergometer at sea level (4 weeks prior) and within 48 hours of arrival to 5035 m (10-day ascent). Power output, beat-to-beat BP, oxygen saturation (SpO2) and heart rate (HR) were recorded during exercise, with resting BP collected from daily medicals during ascent. Before and immediately following exercise at 5035 m, extravascular lung water prevalence was assessed with ultrasound (quantified via B-line count). RESULTS: At altitude, peak power was reduced relative to sea level (p<0.01) in both groups (losartan vs placebo: down 100±29 vs 91±28 W, p=0.55), while SpO2 (70±6 vs 70±5%, p=0.96) and HR (146±21 vs 149±24 bpm, p=0.78) were similar between groups at peak power, as was the increase in systolic BP from rest to peak power (up 80±37 vs 69±33 mm Hg, p=0.56). Exercise increased B-line count (p<0.05), but not differently between groups (up 5±5 vs 8±10, p=0.44). CONCLUSION: Losartan had no observable effect on resting or exercising BP, exercise-induced symptomology of pulmonary hypertension or performance at 5035 m.

Long-term remission of disseminated parathyroid cancer following immunotherapy.

PURPOSE: Parathyroid cancer is a rare tumor associated with poor prognosis particularly when disseminated. While chemotherapy and/or radiotherapy are of no clinical value in disseminated disease, immunotherapy should be considered. SUBJECT AND RESULTS: A patient with CDC73-associated metastatic parathyroid carcinoma was treated with combined anti-hPTH immunotherapy and surgery. CONCLUSIONS: Following five courses of anti-hPTH immunotherapy and subsequent surgery, a 12-year long remission of disseminated parathyroid cancer is reported. This case further supports the ever-expanding spectrum of cancers that may benefit from immunotherapy.

High cutoff versus high-flux haemodialysis for myeloma cast nephropathy in patients receiving bortezomib-based chemotherapy (EuLITE): a phase 2 randomised controlled trial.

BACKGROUND: In multiple myeloma, severe acute kidney injury due to myeloma cast nephropathy is caused by pathogenic free light chain immunoglobulin in serum. High cutoff haemodialysis (HCO-HD) can remove large quantities of free light chain immunoglobulin from serum, but its effect on clinical outcomes is uncertain. We therefore aimed to assess whether HCO-HD could increase the frequency of renal recovery in patients with de novo multiple myeloma, severe acute kidney injury, and myeloma cast nephropathy relative to treatment with standard high-flux haemodialysis (HF-HD). METHODS: In this open-label, phase 2, multicentre, randomised controlled trial (EuLITE), we recruited patients with newly diagnosed multiple myeloma, biopsy-confirmed cast nephropathy, and acute kidney injury that required dialysis from renal services in 16 hospitals in the UK and Germany. Patients were randomly assigned (1:1) by random number generation to receive intensive HCO-HD (in sessions lasting 6-8 h) or standard HF-HD and they were stratified by age and centre. Patients and the medical staff treating them were not masked to treatment allocation. Patients received bortezomib, doxorubicin, and dexamethasone chemotherapy, and were then followed up for 2 years. The primary outcome was independence from dialysis at 90 days after random allocation to groups, which was assessed in an intention-to-treat population. The trial has completed follow-up, and is registered at the ISRCTN registry, number ISRCTN45967602. FINDINGS: Between June 7, 2008, and Sept 18, 2013, we recruited 90 patients, of whom 43 (48%) were randomly assigned to receive HCO-HD and 47 (52%) were randomly assigned to receive HF-HD. All 90 patients were included in the analysis of the primary outcome. One (2%) patient from the HF-HD group withdrew consent before receiving treatment. During treatment, nine (21%) patients from the HCO-HD group and two (4%) patients in the HF-HD group discontinued trial treatment. After 90 days, 24 (56%) patients in the HCO-HD group and 24 (51%) patients in the HF-HD group were independent from dialysis (relative risk 1·09, 95% CI 0·74-1·61; p=0·81). During the 2-year follow-up, 98 serious adverse events were reported in the HCO-HD group and 82 serious adverse events were reported in the HF-HD group. The most common serious adverse events were infections and adverse events related to the cardiovascular and thrombotic and musculoskeletal systems. During the first 90 days, 26 infections were reported in the HCO-HD group and 13 infections were reported in the HF-HD group, including 14 lung infections in the HCO-HD group and three lung infections in the HF-HD group. INTERPRETATION: In this phase 2 study, HCO-HD did not improve clinical outcomes for patients with de novo multiple myeloma and myeloma cast nephropathy who required haemodialysis for acute kidney injury and who received a bortezomib-based chemotherapy regimen relative to those receiving HF-HD. These results do not support proceeding to a phase 3 study for HCO-HD in these patients. FUNDING: Gambro, Janssen, and Binding Site.

Urinary Alpha-1-Acid Glycoprotein Is a Sensitive Marker of Glomerular Protein Leakage at Altitude.

Talks, Ben J., Susie B. Bradwell, John Delamere, Will Rayner, Alex Clarke, Chris T. Lewis, Owen D. Thomas, and Arthur R. Bradwell. Urinary alpha-1-acid glycoprotein is a sensitive marker of glomerular protein leakage at altitude. High Alt Med Biol. 19:295-298, 2018.-Proteinuria is an established feature of ascent to altitude and may be caused by a loss of negative charges on glomerular capillary walls (GCWs). To test this hypothesis, we measured two similar sized but oppositely charged proteins in urine: negatively charged alpha-1-acid glycoprotein (α1-AGP, 41-43 kDa) and positively charged dimeric lambda free light chains (λ-FLCs, 50 kDa). Twenty-four-hour urinary leakage was compared with albumin, a 66 kDa negatively charged protein. We studied 23 individuals (ages 23-78 years, male = 17) at baseline (140 m) and daily during an expedition to 5035 m. The results showed a significant increase in median urinary leakage of α1-AGP (p < 0.0001; 6.85-fold) and albumin (p = 0.0006; 1.65-fold) with ascent to altitude, but no significant increase in leakage of λ-FLCs (p = 0.39; 1.14-fold). α1-AGP correlated with the daily ascent profile (p = 0.0026) and partial pressure of oxygen (p = 0.01), whereas albumin showed no correlation (p = 0.19). Urinary α1-AGP was a more sensitive marker of altitude proteinuria than urinary albumin and λ-FLCs, and supported the possibility of loss of GCW negative charges at altitude.

Acetazolamide reduces exercise capacity following a 5-day ascent to 4559 m in a randomised study.

OBJECTIVE: To assess whether acetazolamide (Az), used prophylactically for acute mountain sickness (AMS), alters exercise capacity at high altitude. METHODS: Az (500 mg daily) or placebo was administered to 20 healthy adults (aged 36±20 years, range 21-77), who were paired for age, sex, AMS susceptibility and weight, in a double-blind, randomised manner. Participants ascended over 5 days to 4559 m, then exercised to exhaustion on a bicycle ergometer, while recording breath-by-breath gas measurements. Comparisons between groups and matched pairs were done via Mann-Whitney U and Pearson's χ2 tests, respectively. RESULTS: Comparing paired individuals at altitude, those on Az had greater reductions in maximum power output (Pmax) as a percentage of sea-level values (65±14.1 vs 76.6±7.4 (placebo); P=0.007), lower VO2max (20.7±5.2 vs 24.6±5.1 mL/kg/min; P<0.01), smaller changes from rest to Pmax for VO2 (9.8±6.2 vs 13.8±4.9 mL/kg/min; P=0.04) and lower heart rate at Pmax (154±25 vs 167±16, P<0.01) compared with their placebo-treated partners. Correlational analysis (Pearson's) indicated that with increasing age Pmax (r=-0.83: P<0.005) and heart rate at Pmax (r=-0.71, P=0.01) reduced more in those taking Az. CONCLUSION: Maximum exercise performance at altitude was reduced more in subjects taking Az compared with placebo, particularly in older individuals. The age-related effect may reflect higher tissue concentrations of Az due to reduced renal excretion. Future studies should explore the effectiveness of smaller Az doses (eg, 250 mg daily or less) in older individuals to optimise the altitude-Az-exercise relationships.

The effect of acetazolamide on saccadic latency at 3459 meters.

OBJECTIVE: The effect of altitude on brain function is not yet well understood, nor is the influence of height and speed of ascent. Additionally, the relationship between acute mountain sickness (AMS) symptoms and brain function at altitude is unclear. We hypothesized that a deterioration from baseline measures of brain function occurs after rapid, mechanical ascent to 3459 m and would be less pronounced in persons taking acetazolamide. METHODS: In this double blind, randomized, placebo-controlled study, 20 healthy volunteers (14 men, 6 women; mean age [±SD] 43 ± 16 years) were alternately allocated to acetazolamide 250 mg or to placebo, taken every 12 hours commencing 3 days before ascent. Prosaccadic and antisaccadic eye movements, heart rate, arterial saturation, and Lake Louise AMS scores were assessed at sea level and 15 to 22 hours after ascent to 3459 m. RESULTS: Arterial oxygen saturation was significantly lower in the placebo group compared to the acetazolamide group at altitude (Wilcoxon signed-rank test, median [interquartile range]: acetazolamide vs placebo: 92% [5] vs 85% [5]; P = .007), with no differences in prosaccadic latency, heart rate, or Lake Louise score. No differences in saccadic latencies from baseline to altitude were observed in the placebo group, whereas prosaccadic latencies were significantly longer at altitude with acetazolamide (altitude vs baseline: 153 ms [41] vs 176 ms [52], P = .008). CONCLUSIONS: Brain function, measured by saccadic eye movements, appears to be unimpaired after rapid ascent to 3459 m. Although acetazolamide improves oxygen saturations, it may worsen prosaccades, possibly indicating adverse effects of acetazolamide on brain function at moderate altitude.

Exercise limitation of acetazolamide at altitude (3459 m).

OBJECTIVE: To assess the effect of acetazolamide (Az) on exercise performance during early acclimatization to altitude. METHODS: Az (250 mg twice daily) or placebo was administered for 3 days in a double-blind, randomized manner followed by a rapid ascent to 3459 m in the Italian Alps. Twenty healthy adults (age range, 18-67 years) were tested at 60% of sea-level peak power output for 15 minutes on a bicycle ergometer after 16 to 27 hours of altitude exposure. Exercise performance was measured in relation to peripheral oxygen saturations measured from pulse oximetry (Spo2), Lake Louise acute mountain sickness (AMS) score, and perceived difficulty. RESULTS: At altitude, resting Spo2 was higher in the Az group compared with placebo (P < .001). The highest AMS scores were in 4 of the placebo individuals with the lowest resting Spo2 (P < .05). During the exercise test, Spo2 fell in all but 1 subject (P < .001) and was reduced more in the Az group (P < .01). Four Az and 1 placebo subject were unable to complete the exercise test; 4 of these 5 had the largest fall in Spo2. The perception of exercise difficulty was higher in the Az subjects compared with those taking the placebo (P < .01). There was an age relationship with exercise limitation; 4 of the 9 older than 50 years failed to complete the test whereas only 1 of 11 younger than 50 years failed, and there were no failures in the 6 younger than 30 years (P < .05). CONCLUSIONS: In this study group, and despite higher resting Spo2, Az may have compromised exercise at 3459 m altitude during early acclimatization, particularly in older subjects.

Ratio of involved/uninvolved immunoglobulin quantification by Hevylite™ assay: clinical and prognostic impact in multiple myeloma.

BACKGROUND: HevyLite™ is a new, recently developed method that facilitates separate quantification of the kappa- and lambda-bounded amounts of a given immunoglobulin (Ig). Using this method, we measured intact immunoglobulin (heavy/light chain; HLC) IgG-kappa, IgG-lambda, IgA-kappa, IgA-lambda individually, as well as their deriving ratios (HLCR) in a series of IgG or IgA multiple myeloma (MM) patients, to investigate and assess the contribution of these tests to disease evaluation. PATIENTS AND METHODS: HevyLite™ assays were used in sera from 130 healthy individuals (HI) and 103 MM patients, at time of diagnosis. In patients, the level of paraprotein was IgG in 78 (52 IgG-kappa, 26 IgG-lambda) and IgΑ in 25 (13 IgΑ-kappa, 12 IgΑ-lambda). Durie-Salmon and International Staging System stages were evenly distributed. Symptomatic patients (n = 77) received treatment while asymptomatic ones (n = 26) were followed. Patients' median follow-up was at 32.6 months. HLCR was calculated with the involved Ig (either G or A) as numerator. RESULTS: In HI, median IgG-kappa was 6.85, IgG-lambda 3.81, IgA-kappa 1.19 and IgA-lambda 0.98 g/L. The corresponding median involving HLC values in MM patients were 25.8, 23.45, 28.9 and 36.4 g/L. HLC-IgG related to anemia, high serum free light chain ratio and extensive bone marrow infiltration, while high HLCR correlated with the same plus increased ß2-microglobulin. In addition, increased HLCR and the presence of immunoparesis correlated with time to treatment. Patients with high HLCR had a significantly shorter survival (p = 0.022); HLCR retained its prognostic value in multivariate analysis. CONCLUSIONS: HLC and HLCR quantify the precise amount of the involved immunoglobulin more accurately than other methods; moreover, they carry prognostic information regarding survival in MM patients.

Novel M-component based biomarkers in Waldenström's macroglobulinemia.

Waldenstrom's macroglobulinemia (WM) is an indolent B-cell lymphoma of the lymphoplasmacytic type accompanied by a serum IgM component. However, conventional IgM quantification lacks sensitivity, does not precisely reflect tumor burden of WM, and, although being the main marker for monitoring response to treatment, may not be accurate. New serum M-component based biomarkers were developed for routine practice in recent years, such as the Freelite® test and more recently the Hevylite test®. Studies have shown that Freelite was a prognostic marker for time to treatment in WM that helps monitoring disease response or progression. Hevylite measures IgMkappa and IgMlambda, separately, and might provide true quantitative measurement of the IgM M-spike. Although current data are preliminary, Hevylite® might replace the current technique to measure IgM M-spike in the years to come. We summarize herein studies conducted to delineate the role of these tests in WM.

Aggregated serum free light chains may prevent adequate removal by high cut-off haemodialysis.

Free light chain (FLC) removal by high cut-off haemodialysis has been described as an adjuvant therapy for the management of patients with severe renal failure complicating multiple myeloma. The two cases reported here are the first patients in whom this treatment did not remove FLCs. In both patient's sera, size-exclusion chromatography identified large FLC aggregates, with molecular weights above the cut-off of the dialyser. It is important for clinicians to be aware of FLC aggregates as a reason for failure to remove FLCs by this new modality.

Outcome in renal Al amyloidosis after chemotherapy.

PURPOSE: Chemotherapy in AL (primary or light chain) amyloidosis is associated with improved survival, but its effect on renal outcome has not been examined systematically. The purpose of this study was to evaluate the effect of chemotherapy on clinical outcome among patients with renal AL amyloidosis. PATIENTS AND METHODS: We evaluated factors influencing survival among 923 patients with renal AL amyloidosis observed during a 21-year period, including 221 patients who became dialysis dependent. Factors associated with renal outcome were analyzed, including serum free light chain (FLC) response to chemotherapy using a simple subtraction formula applicable to all stages of chronic kidney disease. Patient survival and graft survival were analyzed in 21 renal transplantation recipients. RESULTS: Median survival from diagnosis for the whole cohort was 35.2 months. Magnitude of FLC response with chemotherapy was strongly and independently associated with overall survival (P < .001) and renal outcome. Evaluable patients achieving more than 90% FLC response had a significantly higher rate of renal responses and lower rate of renal progression compared with patients achieving a 50% to 90% response, whose renal outcomes were, in turn, better than patients achieving less than 50% FLC response (P < .001). Median survival from dialysis dependence was 39.0 months, and median survival from renal transplantation was 89.0 months. CONCLUSION: Renal outcome and overall outcome in AL amyloidosis are strongly associated with FLC response to chemotherapy and are best among patients achieving more than 90% suppression of the amyloidogenic monoclonal component. Survival on dialysis was substantially superior to that previously reported, and renal transplantation should be considered in selected patients with AL amyloidosis with end-stage renal disease.

Antibodies to human serum amyloid P component eliminate visceral amyloid deposits.

Accumulation of amyloid fibrils in the viscera and connective tissues causes systemic amyloidosis, which is responsible for about one in a thousand deaths in developed countries. Localized amyloid can also have serious consequences; for example, cerebral amyloid angiopathy is an important cause of haemorrhagic stroke. The clinical presentations of amyloidosis are extremely diverse and the diagnosis is rarely made before significant organ damage is present. There is therefore a major unmet need for therapy that safely promotes the clearance of established amyloid deposits. Over 20 different amyloid fibril proteins are responsible for different forms of clinically significant amyloidosis and treatments that substantially reduce the abundance of the respective amyloid fibril precursor proteins can arrest amyloid accumulation. Unfortunately, control of fibril-protein production is not possible in some forms of amyloidosis and in others it is often slow and hazardous. There is no therapy that directly targets amyloid deposits for enhanced clearance. However, all amyloid deposits contain the normal, non-fibrillar plasma glycoprotein, serum amyloid P component (SAP). Here we show that administration of anti-human-SAP antibodies to mice with amyloid deposits containing human SAP triggers a potent, complement-dependent, macrophage-derived giant cell reaction that swiftly removes massive visceral amyloid deposits without adverse effects. Anti-SAP-antibody treatment is clinically feasible because circulating human SAP can be depleted in patients by the bis-d-proline compound CPHPC, thereby enabling injected anti-SAP antibodies to reach residual SAP in the amyloid deposits. The unprecedented capacity of this novel combined therapy to eliminate amyloid deposits should be applicable to all forms of systemic and local amyloidosis.

Differential progression of renal scarring and determinants of late renal recovery in sustained dialysis dependent acute kidney injury secondary to myeloma kidney.

BACKGROUND: Most cases of dialysis-dependent acute kidney injury due to myeloma cast nephropathy do not recover renal function. Renal biopsy typically shows cast formation, direct tubular injury and interstitial inflammation caused by nephrotoxic monoclonal free light chains (FLC). Established scarring at presentation is rarely severe. There is little data on in situ evolution of renal injury. AIMS: To conduct a detailed histological study of four patients with cast nephropathy. METHODS: Cast nephropathy was confirmed by renal biopsy. Treatment consisted of chemotherapy and high cut-off dialysis to maximise extracorporeal removal of FLC and reduce renal toxicity. All four patients remained dialysis dependent at 6 weeks, at which time they underwent a further biopsy. RESULTS: Three patients achieved independence from dialysis. Six-week biopsies showed differential changes in chronic damage from no progression, to accelerated progression of scarring from 10% to 42%, despite a rapid and sustained fall in FLC in all patients. In three patients there was a major reduction in intratubular cast numbers; these patients subsequently recovered renal function. In one patient who continued to have high cast formation at 6 weeks there was no subsequent renal recovery. CONCLUSIONS: Some FLC clones can promote rapid renal scarring. Significant reductions in cast formation on repeat biopsy may identify the potential for late renal recovery. Early diagnosis and treatment may prove crucial in determining renal recovery. Patients who have not recovered renal function after a period of treatment may be usefully reassessed by repeat biopsy for quantitative analysis of chronic damage and cast numbers.

The ratio of parathyroid hormone as measured by third- and second-generation assays as a marker for parathyroid carcinoma.

BACKGROUND: Parathyroid carcinoma (PCa) is a rare disease that can be difficult to differentiate initially from severe benign parathyroid adenoma. PCa oversecrete the amino form of PTH, which is recognized by third-generation but not by second-generation PTH immunoassays. In normal individuals, the third-generation to second-generation PTH ratio should be less than 1. OBJECTIVE: Our objective was to study the utility of the third-generation to second-generation PTH ratio as a means of distinguishing PCa patients (n=24) from control groups with and without disorders of calcium secretion, including patients on renal hemodialysis (n=74), postrenal transplantation (n=60), and primary hyperparathyroidism (PHP; n=30). SETTING AND DESIGN: We conducted a retrospective, laboratory-based study at tertiary referral academic centers. RESULTS: The mean third-generation to second-generation ratio was 0.58+/-0.10 in the dialysis patients, 0.54+/-0.10 in the renal transplant group, 0.54+/-0.12 in the elderly healthy patients, and 0.68+/-0.11 in the PHP group. All 245 of these patients presented a PTH third-generation to second-generation ratio of less than 1. In contrast, we observed an inverted third-generation to second-generation PTH ratio of more than one in 20 PCa patients, whereas only four PCa patients had a normal ratio of less than 1. CONCLUSIONS: An inverted third-generation to second-generation PTH ratio occurred in the majority of patients with advanced PCa and was absent in all 245 relevant controls. A third-generation to second-generation PTH ratio higher than 1 had a sensitivity of 83.3% and a specificity of 100% among PHP patients as a marker for PCa. This ratio may be useful to identify patients with PCa earlier and to detect patients either at risk of developing PCa or those in whom recurrence is taking place.

Serum free light chain immunoassay as an adjunct to serum protein electrophoresis and immunofixation electrophoresis in the detection of multiple myeloma and other B-cell malignancies.

BACKGROUND: Protein and immunofixation electrophoresis of serum and urine are established as diagnostic aids for identifying monoclonal gammopathies. However, many patient sera sent to laboratories are not accompanied by urine samples and recent reports suggest the use of serum free light chain (sFLC) analysis in combination with serum protein electrophoresis (SPE) and immunofixation electrophoresis (lFE) could eliminate the need for urinalysis. The aim of the study was to assess the utility of sFLC measurement in addition to serum protein electrophoresis in the identification of patients with B-cell malignancies. METHODS: A total of 952 serum samples were analysed by serum protein electrophoresis and those with abnormal bands were analysed by immunofixation. sFLCs were measured in a retrospective manner by automated assay. RESULTS: In our study of 952 patient sera, it was found that FLC analysis identified 23 additional cases of B-cell malignancies which were missed by SPE. CONCLUSIONS: The additional malignancies identified by sFLC analysis add support for its inclusion in the routine screening protocol for B-cell malignancies.