Omran Bakoush

Development and validation of GFR-estimating equations using diabetes, transplant and weight

BACKGROUND We have reported a new equation (CKD-EPI equation) that reduces bias and improves accuracy for GFR estimation compared to the MDRD study equation while using the same four basic predictor variables: creatinine, age, sex and race. Here, we describe the development and validation of this equation as well as other equations that incorporate diabetes, transplant and weight as additional predictor variables. METHODS Linear regression was used to relate log-measured GFR (mGFR) to sex, race, diabetes, transplant, weight, various transformations of creatinine and age with and without interactions. Equations were developed in a pooled database of 10 studies [2/3 (N = 5504) for development and 1/3 (N = 2750) for internal validation], and final model selection occurred in 16 additional studies [external validation (N = 3896)]. RESULTS The mean mGFR was 68, 67 and 68 ml/min/ 1.73 m(2) in the development, internal validation and external validation datasets, respectively. In external validation, an equation that included a linear age term and spline terms in creatinine to account for a reduction in the magnitude of the slope at low serum creatinine values exhibited the best performance (bias = 2.5, RMSE = 0.250) among models using the four basic predictor variables. Addition of terms for diabetes and transplant did not improve performance. Equations with weight showed a small improvement in the subgroup with BMI <20 kg/m(2). CONCLUSIONS The CKD-EPI equation, based on creatinine, age, sex and race, has been validated and is more accurate than the MDRD study equation. The addition of weight, diabetes and transplant does not significantly improve equation performance.

Arab nations lagging behind other Middle Eastern countries in biomedical research: a comparative study

BackgroundAnalysis of biomedical research and publications in a country or group of countries is used to monitor research progress and trends. This study aims to assess the performance of biomedical research in the Arab world during 2001–2005 and to compare it with other Middle Eastern non-Arab countries.MethodsPubMed and Science Citation Index Expanded (SCI-expanded) were searched systematically for the original biomedical research publications and their citation frequencies of 16 Arab nations and three non-Arab Middle Eastern countries (Iran, Israel and Turkey), all of which are classified as middle or high income countries.ResultsThe 16 Arab countries together have 5775 and 14,374 original research articles listed by PubMed and SCI-expanded, respectively, significantly less (p < 0.001) than the other three Middle Eastern countries (25,643 and 49,110). The Arab countries also scored less when the data were normalized to population, gross domestic product (GDP), and GDP/capita. The publications from the Arab countries also have a significantly lower (p < 0.001) citation frequency.ConclusionThe Arab world is producing fewer biomedical publications of lower quality than other Middle Eastern countries. Studies are needed to clarify the causes and to propose strategies to improve the biomedical research status in Arab countries.

Prediction of relative glomerular filtration rate in adults: New improved equations based on Swedish Caucasians and standardized plasma‐creatinine assays

Objective. To evaluate newly developed equations predicting relative glomerular filtration rate (GFR) in adult Swedish Caucasians and to compare with the Modification of Diet in Renal Disease (MDRD) and Mayo Clinic equations using enzymatic and zero‐calibrated plasma creatinine assays. Material and methods. GFR was measured with iohexol clearance adjusted to 1.73 m2. One population sample (n = 436/Lund) was used to derive an equation based on plasma‐creatinine/age/gender, and a second with the addition of lean body mass (LBM). Both equations were validated in a separate sample (n = 414/Malmö). The coefficients of the equations were eventually fine‐tuned using all 850 patients and yielding Lund–Malmö equations without (LM) and with LBM‐term (LMLBM). Their performance was compared with the MDRDCC (conventional creatinine calibration), MDRDIDMS (isotope dilution mass spectroscopy traceable calibration) and Mayo Clinic equations. Results. The Lund equations performed similarly in both samples. In the combined set, the Mayo Clinic/MDRDCC resulted in +19.0/+10.2 % median bias, while bias for the other equations was<10 %. LMLBM had the highest accuracy (86 % of estimates within 30 % of measured GFR), significantly (p<0.001) better than for MDRDIDMS (80 %). In men with BMI<20 kg/m2, MDRDIDMS/LM had +46 %/+19 % median bias. MDRDIDMS also overestimated GFR by 22 %/14 % in men/women above 80 years of age. The LMLBM equation had<10 % bias irrespective of BMI, age or GFR except for a 15 % negative bias at GFR⩾90 mL/min/1.73 m2. Conclusion. The newly developed Lund–Malmö equations for GFR estimation performed better than the MDRDIDMS and Mayo Clinic equations in a Swedish Caucasian sample. Inclusion of an LBM term improved performance markedly in certain subgroups.

Standardization of p-creatinine assays and use of lean body mass allow improved prediction of calculated glomerular filtration rate in adults: A new equation

Objective. To evaluate the Cockcroft–Gault (CG) equation, using various body weight expressions, and the Sawyer equation in predicting glomerular filtration rate (GFR) using an enzymatic and zero‐calibrated Jaffe plasma‐creatinine assay, and to derive a new robust equation in adults. Material and methods. The CG weight measures included total, ideal and adjusted body weight (ABW; lowest of total and ideal) and two lean body mass (LBM) expressions, while the Sawyer equation is based primarily on LBM. Iohexol clearance was used to measure GFR. One derivation set (n = 436; enzymatic assay) was used to evaluate and bias‐adjust existing equations when indicated, and to derive a new equation based on plasma‐creatinine, age, gender and the body weight measure yielding the best adjusted R2. All equations were then validated in a separate set (n = 414; Jaffe assay). Results. The existing equations all performed similarly in both sets. Prediction errors of equations based on LBM showed no correlation with BMI. The CGABW and Sawyer equations performed best. The new equation with LBM yielded the highest adjusted R2. In the combined set (n = 850), its accuracy (86 %/98 % of estimates within 30 %/50 % of measured GFR) was significantly better than for the CGABW (79 %/95 %) and Sawyer equations (79 %/93 %) (p<0.001) for each 30 mL/min GFR subgroup within ±30 % and ±50 %, except within ±30 % >120 mL/min. Prediction error did not correlate with BMI, age or gender. Conclusion. A new creatinine‐based equation derived in a mainly Caucasian patient sample is a better predictor of GFR than CG‐type equations irrespective of the body weight measure used or, if bias‐adjusted, when using zero‐calibrated creatinine assays.

Monocyte Chemoattractant Protein 1 is a Prognostic Marker in ANCA-Associated Small Vessel Vasculitis

Background. The (anti neutrophil cytoplasmatic autoantibody ANCA), associated small vessel vasculitides (ASVV) are relapsing-remitting inflammatory disorders, involving various organs, such as the kidneys. (Monocyte chemoattractant protein 1 MCP-1) has been shown to be locally up regulated in glomerulonephritis and recent studies have pointed out MCP-1 as a promising marker of renal inflammation. Here we measure urinary cytokine levels in different phases of disease, exploring the possible prognostic value of MCP-1, together with (interleukin 6 IL-6), (interleukin 8 IL-8) and (immunoglobulin M IgM). Methods. MCP-1, IL-6 and IL-8 were measured using commercially available ELISA kits, whereas IgM in the urine was measured by an in-house ELISA. Results. The MCP-1 levels in urine were significantly higher in patients in stable phase of the disease, compared with healthy controls. Patients in stable phase, with subsequent adverse events; had significantly higher MCP-1 values than patients who did not. MCP-1 and IgM both tended to be higher in patients relapsing within three months, an observation, however, not reaching statistical significance. Urinary levels of IL-6 correlated with relapse tendency, and IL-8 was associated with disease outcome. Conclusions. Patients with ASVV have raised cytokine levels in the urine compared to healthy controls, even during remission. Raised MCP-1 levels are associated with poor prognosis and possibly also with relapse tendency. The association with poor prognosis was stronger for U-MCP-1 than for conventional markers of disease like CRP, BVAS, and ANCA, as well as compared to candidate markers like U-IgM and U-IL-8. We thus consider U-MCP-1 to have promising potential as a prognostic marker in ASVV.

Diagnostic and prognostic significance of proteinuria selectivity index in glomerular diseases

The proteinuria selectivity index (SI) describes changes of the glomerular permeability for macromolecules. In the present study, we examine the implications of SI as a diagnostic (199 patients) and a prognostic (49 patients) marker in glomerular diseases. Using SI based on alpha(2)-macroglobulin (alpha(2)-M-SI) or on IgM (IgM-SI) we found that minimal change nephropathy could be discriminated by low SI values and crescentic necrotizing glomerulonephritis by high SI values compared to other diseases. SI based on IgG (IgG-SI) was less useful in determining specific diagnoses. During a follow-up of 46 months creatinine clearance (Cr cl) decreased 36% in a group of patients with high IgG-SI (>0.2) and 38% in a group of patients with high IgM-SI (>1.5(-3)) compared to only 8% in patients with low IgG-SI (</=0.2) or low IgM-SI (</=1.5(-3)). Furthermore, Cr cl decreased more than 30% in 12 (92%) out of thirteen patients with high baseline levels of both IgG-SI and IgM-SI compared to three out of thirteen patients with low baseline values of both the indexes. The decline rate of Cr cl correlated significantly to the SI levels but not to the degree of albuminuria. The findings of the study indicate that urinary excretion of high-molecular-weight proteins, and not of albumin, is a potential prognostic marker in proteinuric glomerulopathies and it may also serve as valuable diagnostic aid in these disorders.

PubMed Medical publications from Libya

Medical research and publications are the back-bone for advancing the medical field. We identified the Pubmed medical publications that are affiliated with Libya to shed some light on the contribution of this countrys medical community to the PubMed database. All publications affiliated with Libya in the PubMed were counted over a five year period ending December 2006. We also used the same method to obtain data on the PubMed medical publications from Tunisia, Morocco and Yemen. Tunisia had the largest number of PubMed publications among the studied countries: 20.4 publications per million population per year and 7.2 publications per year per one billion US

High incidence of childhood type 1 diabetes in Al-Madinah, North West Saudi Arabia (2004-2009).

GDP. Libya had much fewer publications: 2.4 publications per million population per year and 0.4 publications per one billion US

Different fractions of human serum glycoproteins bind galectin-1 or galectin-8, and their ratio may provide a refined biomarker for pathophysiological conditions in cancer and inflammatory disease.

GDP. The citation frequency for Libyan published research was very low compared to Tunisian and Moroccan related research. Conclusion: This preliminary analysis shows that medical research output in Libya is about twenty times less than in other countries with similar backgrounds, and that it needs to be enhanced.

Increased urine IgM excretion predicts cardiovascular events in patients with type 1 diabetes nephropathy

Habeb AM, Al‐Magamsi MSF, Halabi S, Eid IM, Shalaby S, Bakoush O. High incidence of childhood type 1 diabetes in Al‐Madinah, North West Saudi Arabia (2004–2009).