Membranoproliferative glomerulonephritis (MPGN) is a pattern of glomerular injury. Based on the etiology of MPGN, Drs. Sethi and Fervenza proposed a new histologic classification of MPGN into Ig/IC-mediated MPGN and complement-mediated MPGN. In this “Hot Topic,” Senjeev Sethi, M.D., Ph.D., demonstrates the use of the new classification with case studies.

Membranoproliferative glomerulonephritis (MPGN) is a pattern of glomerular injury. Based on the etiology of MPGN, Drs. Sethi and Fervenza proposed a new histologic classification of MPGN into Ig/IC-mediated MPGN and complement-mediated MPGN. In this “Hot Topic,” Senjeev Sethi, M.D., Ph.D., demonstrates the use of the new classification with case studies.

In this “Hot Topic,” Bobbi Pritt, M.D., discusses how Lyme disease is the most common vector-borne illness in the United States and Europe and caused primarily by Borrelia burgdorferi in the United States, while B burgdorferi, B afzelii, and B garinii cause Lyme disease in Europe. We will also discuss using PCR and melting curve analysis to identify a new species of Borrelia.

In this “Hot Topic,” Elitza Theel, Ph.D., discusses how common cases of presumed Lyme disease go unreported each year and discusses scenarios in which testing for Lyme disease is indicated and reviews both recommended and inappropriate testing methodologies. The overall focus is on performance of the CDC endorsed two-tiered serologic testing algorithm and the latest CDC recommendations.

The diagnosis of Myeloproliferative Neoplasm (MPN) must include an integrated approach and combine the clinical findings with laboratory results. In our latest “Hot Topic,” Rong He, M.D., discusses the subclassification of MPNs and the use of JAK2, CALR, and MPL mutational analysis in diagnosis and prognosis.

Flow cytometric immunophenotyping method can be useful in assessing myeloid dysmaturation. In this “Hot Topic,” Dragon Jevremovic, M.D., Ph.D., describes a new flow cytometric test to detect aberrant patterns of expression in the diagnosis of myelodysplastic syndrome.