Heavy+light chain monitoring correlates with clinical outcome in multiple myeloma patients.

Novel anti-myeloma agents have improved patient response rates, which are historically based on reductions of the M-protein. These methods can be inaccurate for quantifying M-proteins at low concentrations. We compared the consistency and clinical impact of response assignment by electrophoretic and heavy+light chain (HLC) immunoassays post-consolidation in 463 newly diagnosed patients. The two methods gave similar assignments in patients with partial (PR; 79% agreement) or complete response (⩾CR; 92%). However, in patients achieving very good PR (VGPR) there was poor concordance between methods (45%). Median progression-free survival (PFS) for standard VGPR patients was 34.5 months; HLC responses stratified these patients further into PR, VGPR and ⩾CR, with median PFS of 21.3, 28.9 months and not reached, respectively; P<0.001. At this time, abnormal HLC ratios had better concordance with multiparametric flow cytometry (sensitivity 10-4) (37 and 34% positive, respectively), compared to immunofixation (62% positive). In addition, HLC-pair suppression was identified in 38% of patients and associated with shorter PFS (30.6 months vs not reached; P<0.001). We conclude that HLC monitoring could augment electrophoretic assessments in patients achieving VGPR. The prognostic significance of HLC responses might partly depend on the patients' ability to recover their immune system, as determined by normalisation of HLC measurements.

Neutrophil gelatinase-associated lipocalin, a marker of tubular dysfunction, is not increased in long-term virologically controlled patients receiving a tenofovir/emtricitabine + nevirapine regimen.

OBJECTIVES: Tenofovir may be associated with nephrotoxicity. Several studies have shown that an early increase in urinary neutrophil gelatinase-associated lipocalin (NGAL) may predict the occurrence of acute kidney injury. We investigated urine and plasma NGAL in patients on long-term treatment with nevirapine associated with either tenofovir/emtricitabine or abacavir/lamivudine. PATIENTS AND METHODS: We studied 40 virologically controlled Caucasian patients on stable treatment (median >4 years) with tenofovir/emtricitabine + nevirapine (n = 20) or abacavir/lamivudine + nevirapine (n = 20), and no history of kidney disease, high blood pressure or diabetes. Plasma immunovirological parameters (NGAL and C-reactive protein) and urinary NGAL, ß2-microglobulin and α1-microglobulin were measured during a routine clinical visit. RESULTS: Median concentrations of NGAL were in the normal range, but were significantly higher in the abacavir/lamivudine group compared with the tenofovir/emtricitabine group both in the plasma, at 74.9 and 66.0 ng/mL (P = 0.032), respectively, and in the urine, at 36.1 and 12.8 ng/mL (P = 0.017), respectively. CONCLUSIONS: Plasma and urinary NGAL concentrations remained in the normal range in this long-term virologically controlld population without any overt renal disease. The usefulness of NGAL in detecting sub-clinical renal dysfunction appears to be very limited.

Effect of stress on clinical reasoning during simulated ambulatory consultations.

BACKGROUND: The goal of this study was to examine the impact of subjective and physiological stress responses on medical students' diagnostic reasoning and communication skills. METHOD: A prospective randomized quantitative study was undertaken, looking at ambulatory consultations in internal medicine. On the first day (baseline day), volunteer year 6 students (n = 41) participated in a simulated ambulatory consultation with standardized patients (SPs). On the second day (study day), one week later, they were randomly assigned to two groups: a low stress (n = 20) and a high stress (n = 21) simulated ambulatory consultation. Stress was measured using validated questionnaires and salivary cortisol. The SPs assessed the students' reasoning and communication. The students completed assessments of their clinical reasoning after the consultations. RESULTS: Although stress measures were all significantly higher in the high-stress condition (all p < 0.05), no differences were found in diagnostic accuracy and justification scores. However, correlational analyses revealed a negative correlation between multiple-stress measures and the students' ability to generate arguments for differential diagnoses. CONCLUSION: Stress was associated with impairments in clinical reasoning, of a nature typically suggestive of premature closure.

[An exceptional component C3 deficiency revealed by serum protein electrophoresis]. / Un exceptionnel déficit héréditaire en fraction C3 du complément dépisté par électrophorèse des protéines sériques.

We report the case of a 5-years old child referred to the pediatric clinic due to a prolonged history of recurrent otitis. Initial immunologic investigation was normal but a severe C3 complement deficiency was detected by the absence of beta 2-globulin protein fraction using serum protein capillary electrophoresis. C3 was not detected in serum and total complement haemolytic activity was decreased. His mother and father had half of the C3 normal plasma level and a heterozygous mutation of the C3 gene. The diagnosis of hereditary deficiency of the third complement component (C3) with compound heterozygous mutation of the gene was made. This defect in complement protein C3, described to date in only 20 families in the world, is associated with repeated infections. The child is treated with oracillin with relatively good control of symptoms.

[Contribution of the laboratory in hypoglycemia diagnosis induced by insulin administration in a 2-year-old girl]. / Apport du laboratoire dans le diagnostic d'une hypoglycémie liée à des injections d'insuline chez un enfant de 2 ans.

We report the case of a 2 year-old child presented to the emergency department following a seizure. The child was hypotonic and examination was unremarkable but laboratory tests confirmed a severe hypoglycaemia. The insulin level, inappropriately high for the glycemia and the peptide C undetectable suggested exogenous hyperinsulinism. We conclude that the hypoglycaemia was likely the result of Munchhausen syndrome by proxy. The specificity of two immunoassays used (Elecsys Roche and IRMA CisBio) for the synthetic analogues of insulin explains the discrepancy between the insulin levels obtained but was crucially useful to the approach of the cause of the hypoglycaemia.