An overview of monoclonal gammapathies

The neoplastic proliferation of single clones of plasma cells causes synthesis of very large amount of monoclonal immunoglobulins consisting of only one type of heavy either the gamma, alpha, mu, delta or epsilon chain or only kappa or lambda light chains. Each monoclonal immunolobulin differs idiotypically from each other. These monoclonal immunoglobulins are also called paraproteins and are frequently associated with a broad heterogeneous group of plasma cell dyscrasias. Occasionally their presence is observed in a few benign conditions and in old age. In the present review a detailed account of different types of monoclonal gammapathies are described.     

An immunological based study of monoclonal gammopathies among suspected individuals in Kashmir region

Serum and urine samples from 513 patients clinically suspected of monoclonal gammopathies over a period of five years (1992–97) were subjected to various immunological procedures viz, electrophoresis, immunoelectrophoresis and immunoglobulin estimations. Laboratory investigations confirmed gammopathies in 10.33%. It was observed that overall age of incidence for monoclonal gammopathies in both sexes was between 42–72 years with a male to female ratio of 1.4∶1. Predominant paraprotein detected was IgG type (75.47%) followed by IgA (16.98%) and Bence Jones proteins (7.55%). Amongst positive patients, 64.16% were having kappa (k) type light chains and 35.84% lambda (δ) type light chains. 69.39% patients with serum M component (IgG and IgA) had Bence Jones proteinuria. Densitometric scanning revealed that majority of IgG type paraprotein was found in the slow gamma globulin region and majority of IgA type paraprotein was found equally distributed between beta and fast gamma globulin regions. Both types had decreased albumin and alpha-2-globulin concentrations as compared to normal controls. Immunoglobulin levels in patients with paraprotein had very high levels of serum IgG (6467.0 mg%) and IgA (2714.0 mg%) in respective types of monoclonal gammopathies; the rest of immunoglobulin classes were either at normal or decreased levels.     

Gamma heavy chain disease in a patient with rheumatoid arthritis – a laboratory evaluation

Introduction:

Heavy chain diseases (HCD) are neoplastic proliferations of B cells which secrete truncated immunoglobulin heavy chains without associated light chains. Being rare and probably underdiagnosed diseases the aim of this report is to show an additional case of gamma heavy chain disease in a 48 year old female patient with rheumatoid arthritis focusing on the laboratory presentation.

Materials and methods:

Laboratory work-up included agarose gel electrophoresis (AGE), capillary zone electrophoresis (CZE), immunofixation and nephelometrically determined immunoglobulin and immunoglobulin subclasses of the patient’s serum. Urine samples were also subjected to immunofixation and to a SDS-PAGE with consecutive immunoblot.

Results:

Nephelometrically measured elevated IgG concentrations were noted in combination with a decreased gamma globulin region and an increased beta globulin region on AGE. A definite monoclonal spike was not identified on AGE but at least suspected on CZE; finally serum and urine immunofixation demonstrated a monoclonal gamma heavy chain devoid of any corresponding light chains confirming the diagnosis of HCD. Analysis of the gamma heavy chain (HC) with means of SDS-PAGE revealed proteins of 40 kD and 80 kD most likely presenting a truncated HC in its monomeric and dimeric form and possibly leading to the failure of IgG-subclass typing with the applied IgG subclass antisera.

Conclusion:

This case report illustrates a new case of gamma HCD demonstrating variable laboratory manifestations and therefore the need for heightened awareness concerning this disease when confronted with abnormal and discrepant protein profiles in routinely applied laboratory tests.     

Cinderella in Serum Protein Electrophoresis

Paraproteinemia is characterised by clonal proliferation of plasma cells. A common laboratory finding in paraproteinemia being a monoclonal peak in serum protein electrophoresis (M band). But there are factors which produce a peak similar to M spike in serum protein electrophoresis and these factors are known as pseudoparaproteins. This case report discusses a rare cause of pseudo M spike in a known case of autoimmune hemolytic anaemia due to administration of drug-Rituximab, a monoclonal antibody by itself.     

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.     

Multiple Myeloma: A Case of Atypical Presentation on Protein Electrophoresis

Multiple myeloma is a group of B-cell disorders resulting in the secretion of a specific and unique monoclonal immunoglobulin (M-protein). Protein electrophoresis is advised whenever multiple myeloma is suspected. The monoclonal protein migrates as a single entity in the electric field and is detected by the non-specific protein stain as a more intensely stained band superimposed on the usual protein pattern. The M-protein usually migrates in the gamma or beta region of the normal protein pattern; very rarely it may appear in the α2 or even in α1 region. Here we have given an atypical case presentation where the patient with multiple myeloma presented with two M-spike one each in α2 and β-globulin region on agarose gel protein electrophoresis with hypoglobulinemia but with reversed A:G ratio.     

Serum proteins analysis by capillary electrophoresis

The purpose of this study was to evaluate the efficacy of multi-capillary electrophoresis instrument in clinical laboratory. An automated clinical capillary electrophoresis system was evaluated for performing serum proteins electrophoresis and immuno-fixation electrophoresis by subtraction. In this study the performance of capillary electrophoresis was compared with the cellulose acetate membrane electrophoresis and agarose gel immunofixation electrophoresis for serum proteins. The results of capillary electrophoresis and cellulose acetate membrane electrophoresis were good (r=0.89∼0.97) for protein fractions and A/G ratio except for β-gobulin fraction (r=0.60). Both within-run and day to day precisions (CVs) of assay results for 5 main fractions and A/G ratio (n=10) were between 0.3∼6.3%. The reference ranges of serum protein fractions obtained from 200 healthy individuals by cellulose acetate membrane electrophoresis were almost equal to that of capillary electrophoresis except for α-1 globulin fraction. No significant difference of electropherograms between cellulose acetate electrophoresis and capillary electrophoresis was observed in the abnormal serum such as presence of bilirubin (<20mg/dl), hemoglobin (<300 mg/dl), lipid (Intralipos <1%) and samples from patients with acute phase response, liver injury, polyclonal hyper gammaglobulinemia or M-proteinemia. The method of capillary immuno-fixation electrophoresis by subtraction showed good agreement with agarose gel immunofixation electrophoresis by subtraction identifying 30 monoclonal gammmopathy patient samples.     

Serum Paraoxonase Levels In Patients with Acute Liver Disease

Paraoxonase is an anti-oxidant enzyme, which circulates in the plasma, tightly bound to HDL. This enzyme is known to be synthesized in the liver. This study was carried out in order to ascertain the diagnostic utility of this enzyme in acute liver disease. Serum basal as well as salt (NaCl) stimulated paraoxonase was estimated in 50 patients with an established diagnosis of acute liver disease and also in 50 healthy blood donors. Paraoxonase levels were significantly lower in patients as compared with controls (P < 0.05). The ‘receiver operating characteristic’ plot showed that this enzyme has a high degree of sensitivity and specificity for the diagnosis acute liver disease. Serum PON is likely to emerge as an additional test of liver function, as it encompasses three different attributes of hepatic function namely, synthetic capacity, detoxication and secretory functions.     

Spurious Hyperphosphatemia in a Case of Multiple Myeloma

A 50 year old male was admitted in our hospital with anemia and impaired renal function. He was subsequently found to have extremely elevated serum phosphate level (24 mg/dL, reference interval: 2.5–4.5 mg/dL) with normal serum calcium when assayed on a Beckman Coulter AU 480^® analyser. Clinico-biochemical discrepancy led to the suspicion of spurious hyperphosphatemia. Serum total protein was grossly elevated with gross reversal of albumin to globulin ratio. Serum electrophoresis revealed a large M band and was confirmed as Ig G-Kappa type on immunofixation. Subsequently a bone marrow aspiration biopsy confirmed the diagnosis of multiple myeloma. The patient serum was then reassayed for phosphate on a Vitros^® 250 Dry Chemistry platform and the result was within normal reference interval. Paraproteinemias are a common cause of analytical interference in clinical biochemistry laboratories and as multilayered film technology platforms like Vitros^® assay most routine analytes on a protein free filtrate they are unaffected by paraprotein interference. Clinically discordant patient results should always be interpreted keeping such interferences in mind.     

Serum total PSA and free PSA in breast tumors

Now a days measurement of molecular forms of PSA has gained importance in clinical practice. Several studies have demonstrated the production of PSA in female tissues, such as breast. The present piece of work has been undertaken with an objective to estimate the relative proportion of the molecular forms of PSA in serum along with serum testosterone in benign and malignant breast tumor cases and to analyze their association with the severity of the disease process 34 malignant and 26 benign breast disease cases along with 33 healthy controls of same age group were enrolled in this study for evaluation. Serum testosterone was measured by ELISA, whereas serum total PSA (TPSA) and free PSA (FPSA) were estimated by electrochemiluminescence immunoassay. A significant rise of fasting plasma glucose along with prominent dyslipidemia was observed in breast tumor cases. Marked rise in serum testosterone as well as TPSA and FPSA was documented in both benign and malignant breast tumor cases. Serum testosterone revealed a significant positive association with both TPSA and FPSA pointing towards an etiological association between them. However, surgical removal of tumor mass resulted in a marked decline of presurgical value of both TPSA and FPSA with a non-significant fall in serum testosterone revealing tumor tissue as the source of FPSA and TPSA. Thus, estimation of PSA provides prognostic information that may assist in future treatment.     

黑僵菌var.majus核型的电泳分析

用脉冲凝胶电泳（ｐｕｌｓｅｄｆｉｅｌｄｇｅｌｅｌｅｃｔｒｏｐｈｏｒｅｓｉｓ,ＰＦＧＥ）技术分析了黑僵菌ｖａｒ．ｍａｊｕｓ（Ｍｅｔａｒｈｉｚｉｕｍａｎｉｓｏｐｌｉａｅｖａｒ．ｍａｊｕｓ）核型．得出黑僵菌ｖａｒ．ｍａｊｕｓ至少有７条染色体,其大小在１．１～６．５Ｍｂｐ之间,３菌株的核型大小为２１．９～２６．４Ｍｂｐ．黑僵菌ｖａｒ．ｍａｊｕｓ核型在菌株间存在多型性．     

Determining the SARS-CoV-2 serological immunoassay test performance indices based on the test results frequency distribution

IntroductionCoronavirus disease 2019 (COVID-19) is known to induce robust antibody response in most of the affected individuals. The objective of the study was to determine if we can harvest the test sensitivity and specificity of a commercial serologic immunoassay merely based on the frequency distribution of the SARS-CoV-2 immunoglobulin (Ig) G concentrations measured in a population-based seroprevalence study.Materials and methodsThe current study was conducted on a subset of a previously published dataset from the canton of Geneva. Data were taken from two non-consecutive weeks (774 samples from May 4-9, and 658 from June 1-6, 2020). Assuming that the frequency distribution of the measured SARS-CoV-2 IgG is binormal (an educated guess), using a non-linear regression, we decomposed the distribution into its two Gaussian components. Based on the obtained regression coefficients, we calculated the prevalence of SARS-CoV-2 infection, the sensitivity and specificity, and the most appropriate cut-off value for the test. The obtained results were compared with those obtained from a validity study and a seroprevalence population-based study.ResultsThe model could predict more than 90% of the variance observed in the SARS-CoV-2 IgG distribution. The results derived from our model were in good agreement with the results obtained from the seroprevalence and validity studies. Altogether 138 of 1432 people had SARS-CoV-2 IgG ≥ 0.90, the cut-off value which maximized the Youden’s index. This translates into a true prevalence of 7.0% (95% confidence interval 5.4% to 8.6%), which is in keeping with the estimated prevalence of 7.7% derived from our model. Our model can provide the true prevalence.ConclusionsHaving an educated guess about the distribution of test results, the test performance indices can be derived with acceptable accuracy merely based on the test results frequency distribution without the need for conducting a validity study and comparing the test results against a gold-standard test.     

Association of Aberrations in One Carbon Metabolism with Intimal Medial Thickening in Patients with Type 2 Diabetes Mellitus

The present work was aimed to study the association of one carbon genetic variants, hyperhomocysteinemia and oxidative stress markers, i.e., serum nitrite, plasma malondialdehyde (MDA) and glutathione (GSH) on intimal medial thickening (IMT) in patients with type 2 diabetes mellitus (T2D). A total number of 76 subjects from ACS Medical College and Hospital, Chennai, India were included in the study, i.e., Group I (n = 42) of T2D and Group II (n = 34) of age- and sex matched healthy controls. The glycated haemoglobin was measured by ion-exchange resin method; plasma homocysteine by Enzyme Linked Immunosorbant Assay method; serum nitrite (nitric oxide, NO), plasma MDA and GSH by spectrophotometric methods; the IMT by high frequency ultrasound. The polymorphisms of one carbon genetic variants were genotyped using polymerase chain reaction-restriction fragment length polymorphism and amplified fragment length polymorphism methods. Results indicate that methyltetrahydrofolate homocysteine methyl transferase (MTR) A2756G allele was found to be protective in T2D and the other variants were not significantly associated with T2D. Glutamate carboxypeptidase II (GCP II) C1561T (r = 0.34; p = 0.05) and methylene tetrahydrofolate reductase (MTHFR) C677T (r = 0.35; 0.04) showed positive correlation with plasma homocysteine in T2D cases. In this study, MTR A2756G allele was found to be protective in T2D; GCP II C1561T and MTHFR C677T showed positive association with plasma homocysteine in T2D cases. Among all the genetic variants, MTR A2756G was found influence IMT. RFC 1 G80A and TYMS 5′-UTR 2R3R showed synergistically interact with MTR A2756G in influencing increase in IMT.     

Serum arylsulfatase A assay in metachromatic leukodystrophy: An experience in a neuropsychiatric set-up

Metachromatic leukodystrophy is a lysosomal disease caused mainly by a deficiency of the enzyme arylsulfatase A. The assay of arylsulfatase A in the serum provides a fast and easy method for the confirmatory diagnosis of this disorder. Serum arylsulfatase A was estimated in 52 normal healthy control subjects and 269 patients with symptoms of cerebral white matter disease in order to diagnose and confirm metachromatic leukodystrophy. A total of eight cases of metachromatic leukodystrophy with a low serum arylsulfatase A was detected, of which three cases were of the late-infantile type, four cases the juvenile type and only one case the adult type.     

Platelet factor 3 availability time,plasma phenol and phenolic acids in patients with uremia

Platelet factor 3 availability time (PF3 AT), Prothrombin time (PT), Plasma phenol, phenolic acids, blood urea and serum creatinine were estimated in 31 uremic patients. Significant increase (P<0.01) in PF3 AT and plasma phenolic acid was seen in 100 per cent of cases, while the increase in plasma phenol was seen in 90.3% of cases. The increase in PF3 AT was not uniformly proportional to the increase in plasma phenol or phenolic acids in all cases. Increase in PF3 AT was significant in cases of uremia with bleeding diathesis compared to the cases without bleeding diathesis. Increase in PF3 AT after addition of phenol and urea together to normal platelet rich plasma (PRP) in vitro was greater than the increase in PF3 AT after the addition of phenol or urea alone. Significant decrease (P<0.01) in PF3 AT, plasma phenol, plasma phenolic acids, blood urea and serum creatinine was seen in uremic patients after haemodialysis indicating that the retained toxic metabolites which increase PF3 AT are dializable substances.     

Urinary protein thiols in different grades of proteinuria

Total thiol status of plasma, especially thiol groups over protein contributes maximum to the plasma antioxidant status of the body. Serum protein thiols were found to be decreased in various disease conditions including chronic renal failure patients. Only few studies determined the levels of urinary protein thiols in disease conditions. The current study was designed to know the levels of urinary protein thiols in patients with different grades of proteinuria. The study was conducted on urine of 40 healthy controls and 61 cases with proteinuria. Based on proteinuria cases were further divided into two groups; group I - microproteinuria (150–300 mg protein/d), 32 cases, group II - frank proteinuria (>300 mg protein/d), 29 cases. Urinary thiol levels were determined by spectrophotometric method using dithionitrobenzoic acid. A significant decrease (p<0.01) in urinary thiol in group I and group II cases was observed in present study and this decrease was associated with proteinuria.     

Serum homocysteine levels in cerebrovascular accidents

Hyperhomocysteinemia has been considered an independent risk factor in the development of stroke. The present study was undertaken to evaluate serum homocysteine levels in patients with cerebrovascular accidents among the Manipuri population and to compare with the normal cases. Ninety-three cerebrovascular accident cases admitted in the hospital were enrolled for the study and twenty-seven age and sex matched individuals free from cerebrovascular diseases were taken as control group. Serum homocysteine levels were estimated by ELISA method using Axis homocysteine EIA kit manufactured by Ranbaxy Diagnostic Ltd. India. The finding suggests that hyperhomocysteinemia is associated with cerebrovascular accident with male preponderance, which increases with advancing age. However, whether hyperhomocysteinemia is the cause or the result of cerebrovascular accidents needs further investigations.     

Some biochemical markers in various neoplasms: A multivariate analysis

The analysis of biochemical parameters in 162 patients with various neoplastic disorders along with 50 normal subjects showed significant rise in serum alkaline phosphatase and lactate dehydrogenase as compared to normal subjects. 21 patients with other monoclonal gammopathies which include infection and immunological diseases were also studied. Parameters such as serum calcium, uric acid, total protein, albumin and globulin were also analyzed in 42 (26%) cases of multiple myeloma, 27 (17%) cases of gastro-intestinal malignancies, 22 (14%) cases of urogenital malignancies, 11 (6%) cases of carcinoma breast, 4 (2%) cases of bone tumors, 21 (12%) cases of other monoclonal gammopathies, including 7 (4%) cases of infection and 14 (8%) cases of immunological diseases. The results indicate use of enzymes alkaline phosphatase and lactate dehydrogenase in neoplastic disorders.     

猪血浆中凝血酶、免疫球蛋白等功能蛋白的联合提取

实验对猪血浆中白蛋白、免疫球蛋白、纤维蛋白原及凝血酶等功能蛋白进行了联合提取。通过对各步骤中蛋白的检测确立了一套有效的联合提取方法：将柠檬酸钠抗凝的血浆经冻融处理,离心得到纤维蛋白原沉淀，上清通过吸附法提取凝血酶后再经盐析法分离提取白蛋白及免疫球蛋白。1L血浆可同时提得白蛋白31.41g、免疫球蛋白13.86g、凝血酶粗品0.22g（比活力为38.5U/mg）、纤维蛋白原为2.67g。