Analytical Variation Between Two Different TSH Reagents from the Same Manufacturer.

Thyroid stimulating hormone (TSH) immunoassays are known for giving varying results based on the platform of testing and the generation of kit used. It is generally expected that the results should not vary to affect clinical diagnosis and management. We aimed to perform method comparison study between two TSH assays by the same manufacturer Siemens Healthineers. Results show that there is a large proportional error between the assays with a bias of -3.71mIu/L indicating that TSH assay gives higher values for TSH for the same patient as measured against the TSH3-Ultra kit. This can affect interpretation of results leading to false increase in patients categorized under hypothyroidism and subclinical hypothyroidism. We strongly suggest, to prevent errors in clinical evaluation of a patient with thyroid dysfunction, validation of the performance of the assay and method comparison should be performed in-house.

Early onset mixed cryoglobulinemia in hepatitis C.

Cryoglobulinemia is one of the most common forms of extrahepatic manifestation of chronic hepatitis infection. The phenomenon is generally seen after several years of chronicity predominantly in the female population resulting in arthralgias, purpuras, and other symptoms, due to vasculitis. Here we present a case of incomplete mixed cryoglobulinemia Type III (as per Brouet's classification) in a young boy aged 13 years who presented with an unusual symptom of pruritus. Diagnosis was confirmed by cryoprecipitation test followed by immunofixation. We aim to highlight the difficulty in diagnosis of this rare case/presentation, important investigation pitfalls and how to avoid them.

Serum neutrophil gelatinase associated lipocalin (NGAL) and cystatin C as early predictors of contrast-induced acute kidney injury in patients undergoing percutaneous coronary intervention.

BACKGROUND: Contrast-induced acute kidney injury (AKI) is diagnosed by estimating serum creatinine at 48-72h after diagnostic or interventional coronary angiography. It is too late for an early intervention. Neutrophil gelatinase associated lipocalin (NGAL) and cystatin C are novel markers of AKI. We determined the optimum cut-off level of NGAL and cystatin C in early diagnosis and prediction of AKI in patients undergoing coronary angiography followed by angioplasty. METHODS: In a nested case control study, serum NGAL, cystatin C by ELISA and serum creatinine by Jaffe's kinetic method were estimated at 0, 4, 24 and 48h of coronary angiography followed by angioplasty in 30 cases who developed contrast-induced AKI and 30 subjects who did not develop AKI. eGFR was estimated for both cases and controls by the MDRD equation. ROC was used to determine the optimum cut-off. RESULTS: Serum NGAL increased sharply at 4h after the procedure and then gradually declined to near normal level at 48h in AKI cases. The rise in cystatin C peaked at 24h and then declined but remained high till 48h. In controls, they remained static. The optimum cut-off of serum NGAL and cystatin C was 155.2ng/ml and 0.517mg/l respectively at 4h and 89.5ng/ml and 0.99mg/l respectively at 24h of angiography. Odds ratio for hypertensives to develop AKI was 3.57 (CI: 1.2-11.1, p=0.03). CONCLUSION: Serum NGAL and cystatin C may act as early markers of contrast-induced AKI in patients undergoing percutaneous coronary intervention. Patients with hypertension are susceptible to develop contrast-induced AKI.

Ochronosis of the hip joint: differential diagnosis of inflammatory arthropathy with lytic lesion.

Alkaptonuria or ochronosis is a rare inborn disorder of metabolism which is characterized by deficiency of homogentisic acid oxidase. There is accumulation of homogentisic acid in the connective tissues causing brownish black pigmentation and skeletal damage. The most serious complication of this disease is crippling degenerative arthropathy which presents in late years of life. There is no definitive treatment for the condition. Symptomatic management is the main stay. Surgical management such as arthroplasty is done for severe cases of ochronosis. We report a case of ochronosis of the hip joint presenting with inflammation and lytic lesion which can create confusion and lead to error in diagnosis.

Vitamin D and VDR gene polymorphism (FokI) in epithelial ovarian cancer in Indian population.

INTRODUCTION: Vitamin D deficiency and vitamin D receptor (VDR) gene polymorphism, FokI, is reported to increase the risk of many cancers. Role of vitamin D and its receptor polymorphisms in ovarian cancer has not been clearly defined. OBJECTIVE: To study the levels of serum vitamin D and occurrence of vitamin D receptor gene polymorphism (FokI) in cases of ovarian cancer. MATERIAL AND METHODS: FokI genotyping was done by PCR-RFLP technique and vitamin D levels were estimated by chemiluminescence immunoassay. RESULTS: Serum vitamin D levels were significantly (p < 0.03) lower in ovarian cancer cases as compared to controls. The homozygous (TT) and heterozygous (CT) genotype predispose to the development of ovarian cancer in Indian population (OR: 2.37, 95% CI: 1.04-5.44) as compared to the homozygous (CC) genotype. Vitamin D deficiency and VDR gene polymorphism (FokI) act non-synergistically (p value < 0.4). CONCLUSION: Low blood levels of vitamin D and VDR receptor polymorphism (FokI) might be a risk factor for the development of ovarian cancer. Other novel ligands of vitamin D receptor might be responsible for the non-synergistic effect.

A Case of Light Chain Deposition Disease (LCDD) in a Young Patient.

Light chain disease is a variant of multiple myeloma in which the malignant population of marrow cells produces free monoclonal light chains but no heavy chain or complete immunoglobulin. The monoclonal light chains are small enough to be freely filtered by the kidneys and become Bence-Jones protein. Light chain disease comprises about 18% of multiple myeloma patients. Here we present a case report of a 38-year-old man who initially presented with complaints of pain in back and low grade fever off and on. He was found to have collapse of D9 and D12 vertebrae along with ascites and right pleural effusion and massive proteinuria. Multiple myeloma was considered as a differential diagnosis based on the investigations but eventually the patient was lost to follow up. This case is reported here as the light chain variant of multiple myeloma leading to deposition disease is less commonly reported and presents considerable difficulties in diagnosis.