Placental CD34 immunohistochemistry in fetal vascular malperfusion in stillbirth.

AIM: To assess the use of CD34 immunostaining in diagnosing of fetal vascular malperfusion (FVM) in stillborns. METHODS: We examined 25 independent clinical (pregnancy and fetal outcomes) and 48 placental phenotypes in 100 placentas of consecutive stillborns at ≥20 weeks of gestation. Group 1 comprised 34 cases with no distal villous FVM; Group 2 comprised 36 placentas with clustered distal villous FVM (sclerotic villi, hypovascularity, stromal vascular karyorrhexis, and/or mineralization) determined using hematoxylin-eosin staining not upgraded by CD34 immunostaining, and Group 3 comprised 30 placentas with FVM diagnosed or upgraded by CD34 immunostaining (distal villous endothelial fragmentation and/or villous hypovascularity). RESULTS: Diffuse villous lesions of fetal retention with various degrees were present in approximately 50% of the cases in all groups; however, histological evaluation for FVM was still possible in most stillborns. Abnormal clinical phenotypes were significantly less frequent than abnormal placental phenotypes of FVM (8.6% vs. 24%, respectively). Chronic hypoxic placental injury patterns, fetal blood erythroblastosis, some features of shallow placental implantation, and muscular FVM lesions were most common in Group 2. Only decidual arteriopathy (hypertrophic and or hyaline necrosis/atherosis) was most frequent in Group 3. CONCLUSION: Most distal FVM lesions can be observed on hematoxylin-eosin placental slides only several days following the inciting event. CD34 immunostaining can reveal recent distal villous lesions of FVM featuring segmental villous endothelial fragmentation for de novo diagnosis or for upgrading FVM. Routine CD34 immunostaining has demonstrated FVM to be the major pattern of placental injury in stillborns.

Rapid Emergence of SARS-CoV-2 in the Greater New York Metropolitan Area: Geolocation, Demographics, Positivity Rates, and Hospitalization for 46 793 Persons Tested by Northwell Health.

BACKGROUND: In March 2020, the greater New York metropolitan area became an epicenter for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The initial evolution of case incidence has not been well characterized. METHODS: Northwell Health Laboratories tested 46 793 persons for SARS-CoV-2 from 4 March through 10 April. The primary outcome measure was a positive reverse transcription-polymerase chain reaction test for SARS-CoV-2. The secondary outcomes included patient age, sex, and race, if stated; dates the specimen was obtained and the test result; clinical practice site sources; geolocation of patient residence; and hospitalization. RESULTS: From 8 March through 10 April, a total of 26 735 of 46 793 persons (57.1%) tested positive for SARS-CoV-2. Males of each race were disproportionally more affected than females above age 25, with a progressive male predominance as age increased. Of the positive persons, 7292 were hospitalized directly upon presentation; an additional 882 persons tested positive in an ambulatory setting before subsequent hospitalization, a median of 4.8 days later. Total hospitalization rate was thus 8174 persons (30.6% of positive persons). There was a broad range (>10-fold) in the cumulative number of positive cases across individual zip codes following documented first caseincidence. Test positivity was greater for persons living in zip codes with lower annual household income. CONCLUSIONS: Our data reveal that SARS-CoV-2 incidence emerged rapidly and almost simultaneously across a broad demographic population in the region. These findings support the premise that SARS-CoV-2 infection was widely distributed prior to virus testing availability.