Clinical laboratory characteristics of patients with obstructive jaundice accompanied by dyslipidemia

Spurious dyslipidemia due to paraprotein in a patient with Waldenström macroglobulinemia

INTRODUCTION

Serum lipid profiles play a crucial role in diagnosing and evaluating cardiovascular diseases. However, the presence of paraprotein can lead to inaccurate dyslipidemia results on automated analyzers.

CASE REPORT

A 65-year-old woman whose combined concentrations of HDL-cholesterol (HDL-C) and LDL-cholesterol (LDL-C) consistently surpassed her total serum cholesterol levels over a period of three months presented with unusual lipid component detection. Further analysis revealed the presence of a monoclonal paraprotein, identified as an IgMλ band, with a concentration of 28.0 g/L. The patient was subsequently diagnosed with Waldenström macroglobulinemia. The use of abnormal reaction kinetic curves and the β quantification method, along with an alternative method that did not suffer from interference, revealed that the monoclonal paraprotein interfered with the measurements of HDL-C, LDL-C, apolipoprotein A-I (apoA-I), and apolipoprotein B (apoB) when using the Roche detection system. This interference led to spurious elevated HDL-C concentrations and falsely decreased apoA-I and apoB concentrations, while the LDL-C results were minimally affected. Although diluting the sample normalized the HDL-C and LDL-C measurements, the interference with the apoA-I and apoB assays persisted. No other common biochemical tests were interfered with this paraprotein.

CONCLUSION

Caution is advised when using a homogenous method for direct measurement of HDL-C and LDL-C in patients with monoclonal paraprotein. Techniques to recognize and eliminate this interference are available. However, immunoturbidimetric detection of apoA-I and apoB levels is also susceptible to this interference, which is not readily removable.

Use of therapeutic plasma exchange to remove lipoprotein X in a patient with vanishing bile duct syndrome presenting with cholestasis, pseudohyponatremia, and hypercholesterolemia: A case report and review of literature

INTRODUCTION

Lipoprotein X (Lp-X) is an abnormal lipoprotein found in multiple disease conditions, including liver dysfunction and cholestasis. High Lp-X concentrations can interfere with some laboratory testing that may result in spurious results. The detection of Lp-X can be challenging, and there is currently a lack of consensus regarding the management of Lp-X other than treating the underlying disease.

CASE PRESENTATION

A 42-year-old female with Hodgkin's lymphoma treated with dexamethasone, high dose cytarabine and cisplatin and vanishing bile duct syndrome confirmed by liver biopsy presented with cholestasis, pseudohyponatremia (sodium, 113 mmol/L; reference range 136-146 mmL/L; serum osmolality, 303 mOsm/kg), and hypercholesterolemia (> 2800 mg/dL, reference range < 200 mg/dL). Lp-X was confirmed by lipoprotein electrophoresis (EP). Although she did not manifest any specific signs or symptoms, therapeutic plasma exchange (TPE) was initiated based on laboratory findings of extreme hypercholesterolemia, spuriously abnormal serum sodium, and HDL values, and the potential for short- and long-term sequelae such as hyperviscosity syndrome, xanthoma, and neuropathy. During the hospitalization, she was treated with four 1.0 plasma volume TPE over 6 days using 5% albumin for replacement fluid. After the first TPE, total cholesterol (TC) decreased to 383 mg/dL and sodium was measured at 131 mmol/L. The patient was transitioned into outpatient maintenance TPE to eliminate the potential of Lp-X reappearance while the underlying disease was treated. Serial follow-up laboratory testing with lipoprotein EP showed the disappearance of Lp-X after nine TPEs over a 10-week period.

LITERATURE REVIEW

There are seven and four case reports of Lp-X treated with TPE and lipoprotein apheresis (LA), respectively. While all previous case reports showed a reduction in TC levels, none had monitored the disappearance of Lp-X after completing a course of therapeutic apheresis.

CONCLUSION

Clinicians should have a heightened suspicion for the presence of abnormal Lp-X in patients with cholestasis, hypercholesterolemia, and pseudohyponatremia. Once Lp-X is confirmed by lipoprotein EP, TPE should be initiated to reduce TC level and remove abnormal Lp-X. Most LA techniques are not expected to be beneficial since Lp-X lacks apolipoprotein B. Therefore, we suggest that inpatient course of TPE be performed every other day until serum sodium, TC and HDL levels become normalized. Outpatient maintenance TPE may also be considered to keep Lp-X levels low while the underlying disease is treated. Serum sodium, TC, and HDL levels should be monitored while on maintenance TPE.

An in-fiber sensor for simultaneous measurement of cholesterol concentration and temperature based on SPR and MMI

In this paper, we design an in-fiber two-parameter sensor with multimode fiber (MMF)-Au film coated hollow fiber (HCF)-MMF structure, which can simultaneously excite Surface Plasmon Resonance (SPR) effect and Multimode Interference (MMI) effect. A composite material of Au nanoparticles/β-cyclodextrin (AuNPs/β-CD) is deposited on the surface of the Au film coated HCF to realize highly-sensitive measurement of cholesterol concentration. Here, the AuNPs can not only enhance the measurement sensitivity of the SPR sensor, but also increase the numbers of combination sites of β-CD and cholesterol. Then, to solve the cross-sensitivity problem between temperature and cholesterol, the glycerin is selected as a temperature-sensitive material to fill into the inner channel of the HCF, making the MMI sensor sensitive to temperature, and finally realizing the simultaneous measurement of cholesterol concentration and temperature. The experimental results demonstrate that the wavelength shift of the SPR and the MMI are 12.7 nm and 7.9 nm, respectively, when the cholesterol concentration changes from 0 to 500 nM. The temperature sensitivity of the SPR and the MMI are -0.9 nm/°C and 2.64 nm/°C, respectively, in the temperature range of 30°C-46 °C. In addition, the sensor shows good recognition ability of cholesterol molecules in serum environment, with good stability, selectivity and repeatability, and has broad application prospects in the biomedical field.

The necessity for improving lipid testing reagents: A real world study

BACKGROUND

We investigated the interference of vitamin C (VitC), glycerol fructose, lipoprotein X (LpX) and lipemia on the analysis of serum lipids.

METHODS

Serum were collected from 44 patients with VitC infusion, serum lipid concentrations before and after VitC auto-oxidation were compared. Serum of 31 patients with glycerol fructose infusion were collected, triglycerides (TG) measured by glycerol blanking and non-blanking reagents were compared. Forty-four serum samples suspected to contain LpX were collected, LDL-C measured by reagents from five manufacturers were compared. Lipemia samples were collected, LDL-C measured using five different reagents were compared. The interference rate was considered unacceptable if it was greater than 1/2 total allowable error (TEa).

RESULTS

In patients with VitC infusion, the interference rates of TG and total cholesterol (TC) were -59% (-123%, -28%) and -15% (-21%, -11%), respectively. In patients with glycerol fructose infusion, the interference rate of TG was 13% (4%, 113%). LpX interference led to increased LDL-C results for most reagents. Lipemia caused great interference with LDL-C analysis.

CONCLUSION

VitC, glycerol fructose, LpX and lipemia significantly interfered with lipid assays. The reagent formulation should be improved to get reliable results.

Significant High Lipid Profile in a Woman With Obstructive Jaundice

Gallbladder disease is one of the most common gastrointestinal tract diseases. In obstructive jaundice, there is a reduction in bile flow out of the liver secondary to the blocked bile or pancreatic duct, which leads to excess bile and its products accumulating in the blood. One of these products is lipoprotein X (LpX); its presence is associated with a lipoprotein pattern characterized by an increased concentration of low-density lipoprotein (LDL) cholesterol. Few published articles have reported the association between obstructive jaundice and hyperlipidemia. This report describes a unique case of a Saudi female patient diagnosed with obstructive jaundice, presenting with extreme hypercholesterolemia, which was reduced significantly 1 week after endoscopic retrograde cholangiopancreatography (ERCP). Correct recognition and investigation of the lipid profile are important for differentiating LpX-mediated hypercholesterolemia caused by obstructive jaundice from other causes of elevated LDL concentrations. Differentiation may affect the patient's therapeutic management.

Increased TG to HDL-C ratio is associated with severity of drug-induced liver injury

We investigated the relationship between dyslipidemia and drug-induced liver injury (DILI), especially the level of triglyceride to high-density lipoprotein cholesterol ratio (TG/HDL-C) in severe DILI. In this single-centered retrospective study, of 326 patients with DILI, 221 patients were analyzed. Control groups include medication using group and acute hepatitis B group. The relationship between dyslipidemia and DILI was estimated. Demographic and clinical features were analyzed. Dyslipidemia and TG/HDL-C ratios were compared between DILI and control groups, DILI mild group and severe group. The area under the receiver-operating characteristic curve (AUC) was used to evaluate the credibility of the relationship and to find cut-off points. Dyslipidemia is related to DILI when compared with medication using control group (AOR 4.60; 95% CI 2.81-7.54; P < 0.01) and compared with acute hepatitis B group (AOR 2.12; 95% CI 1.37-3.29; P < 0.01). Dyslipidemia is associated with the severity of DILI (AOR 25.78; 95% CI 7.63-87.1; P < 0.01). TG/HDL-C ratio is higher in DILI group than that of medication using control group, also higher in severe DILI group than that of mild DILI group. AUCs for TG/HDL-C ratio to indicate the severity of DILI was 0.89 (P < 0.05), the cut-off point was 2.35. Dyslipidemia and TG/HDL-C ratio were related to DILI occurrence. Severe liver injury in DILI was associated with dyslipidemia and elevated TG/HDL-C ratio.

When LDL Cholesterol Is Not LDL Cholesterol: LpX, A Clinical Lesson

LpX is a lipoprotein formed in cholestatic conditions and often erroneously reported as LDL-C. A low ApoB level can support the diagnosis of LpX. Treatment should not automatically focus on lowering serum lipid levels, but primarily on resolving the cause of cholestasis. (Level of Difficulty: Advanced.)

Diagnostic performance of novel inflammatory biomarkers based on ratios of laboratory indicators for nonalcoholic fatty liver disease

INTRODUCTION

There is few effective biomarkers for diagnosing nonalcoholic fatty liver disease (NAFLD) in clinical practice. This study was aimed to investigate the predictive ability of novel inflammatory biomarkers, including the monocyte to high-density lipoprotein cholesterol ratio (MHR), neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), and lymphocyte to monocyte ratio (LMR), for NAFLD.

METHODS

A total of 4465 outpatients diagnosed with NAFLD and 3683 healthy controls were enrolled between May 2016 and November 2021 from the West China Hospital of Sichuan University, and anthropometric and laboratory examination data were collected. The two-sample Mann-Whitney U test and binary logistic regression analysis were used to evaluate the correlations between four inflammatory biomarkers and NAFLD. The areas under the curves (AUCs) of receiver operating characteristic were used to evaluate their predictive ability for NAFLD.

RESULTS

The MHR, NLR and LMR were higher in patients with NAFLD than in healthy controls (P<0.001), whereas the PLR was remarkably lower (P<0.001). The OR values of the MHR, NLR, PLR, and LMR were 1.599 (1.543-1.658), 1.250 (1.186-1.317), 0.987(0.986-0.988) and 1.111(1.083-1.139), respectively(P<0.001). After adjusting for confounding factors, MHR was still the most relevant risk factor for NAFLD compared with other inflammatory markers (P<0.001). The AUCs of the MHR, NLR, PLR, and LMR were as follows: 0.663 (0.651-0.675), 0.524 (0.512-0.537), 0.329 (0.318-0.341), and 0.543 (0.530-0.555), respectively (P<0.001). Furthermore, the diagnostic model combining the MHR with alanine aminotransferase, aspartate aminotransferase, total cholesterol, triglycerides, fasting blood glucose, creatinine, uric acid, and body mass index had the best AUC of 0.931 (0.925-0.936).

CONCLUSIONS

MHR was superior to NLR, PLR and LMR as an inflammatory biomarker in the prediction of NAFLD. When combined with relevant laboratory parameters, the MHR may improve the clinical noninvasive diagnosis of NAFLD.

Case report: Unusual and extremely severe lipoprotein X-mediated hypercholesterolemia in extrahepatic pediatric cholestasis

BACKGROUND

Lipoprotein X (LpX) - mediated extremely severe hyperlipidemia is a possible feature detectable in children with syndromic paucity of intralobular bile ducts (Alagille syndrome) but rarely in other types of intra- and/or extrahepatic infantile cholestasis.

CASE PRESENTATION

Here we report on a previously well 18-month child admitted for cholestatic jaundice and moderate hepatomegaly. Laboratory tests at entry showed conjugated hyperbilirubinemia, elevated values of serum aminotransferases, gamma-glutamyl transpeptidase (GGT) and bile acids (100 folds upper normal values). Extremely severe and ever-increasing hypercholesterolemia (total cholesterol up to 1,730 mg/dl) prompted an extensive search for causes of high GGT and/or hyperlipidemic cholestasis, including an extensive genetic liver panel (negative) and a liver biopsy showing a picture of obstructive cholangitis, biliary fibrosis, and bile duct proliferation with normal MDR3 protein expression. Results of a lipid study showed elevated values of unesterified cholesterol, phospholipids, and borderline/low apolipoprotein B, and low high-density lipoprotein-cholesterol. Chromatographic analysis of plasma lipoproteins fractions isolated by analytical ultracentrifugation revealed the presence of the anomalous lipoprotein (LpX). Magnetic resonance cholangiopancreatography and percutaneous transhepatic cholangiography showed stenosis of the confluence of the bile ducts with dilation of the intrahepatic biliary tract and failure to visualize the extrahepatic biliary tract. Surgery revealed focal fibroinflammatory stenosis of the left and right bile ducts confluence, treated with resection and bilioenteric anastomosis, followed by the rapid disappearance of LpX, paralleling the normalization of serum lipids, bilirubin, and bile acids, with a progressive reduction of hepatobiliary enzymes.

CONCLUSION

We have described a unique case of focal non-neoplastic extrahepatic biliary stenosis of uncertain etiology, presenting with unusual extremely high levels of LpX-mediated hypercholesterolemia, a condition which is frequently mistaken for LDL on routine clinical tests.